The NEW FORCE in Power Savings

PowerwoRx e3 Frequently Asked Questions

1. Does the PowerwoRx e3 work in any home? »

2. Installation Considerations? »

2. Installation Considerations?

 

PowerwoRx e3   must be installed by a licensed electrician or the 10-year Warranty is void.  The PowerwoRx e3   mounts next or behind the power panel. Questions regarding proper attachment and wiring should be directed to the electrician who can verify state codes are being complied with.

The Installation Guide which accompanies the product can be found Here.

 

Some specific questions from Electricians…..

1.  Sometimes the panel can be found inside the home away from the meter box. Can it be located elsewhere, and if so how far from the panel is this permitted?   ANSWER:  The PowerwoRx e3   can be remotely located in a garage or some other less-conspicuous location.  Distance from the panel should be minimized. Keep in mind that the two indicator lights are the only indication that the PowerwoRx e3   is operating properly.  Consequently the unit should be located in an area where the lights can be checked.  An inaccessible spot would not be the ideal location.

 

2.  If there were enough room in the panel inside the home, could the PowerwoRx e3   be placed inside the panel box?  ANSWER:  Because the two indicator lights are the only indication that the PowerwoRx e3   is operating properly. The Australian standard does not permit the cover of the power panel to be modified. Locating the unit inside the panel would not be the ideal location.

 

3.  Can the wires coming from the PowerwoRx e3 be shortened or lengthened and if so do they need to be the same length?  ANSWER:  Yes the wires can be shortened to whatever length is necessary and no the wires do not need to be the same length. Continental Power allows the lengthening of the wires to accommodate mounting the unit further away from the meter box than the current wiring allows.  As a general rule, the length of the wires should be kept as short as possible and electricians should follow standard electrical code regarding adding wire to the unit.

 

4.  Can PowerwoRx e3 be mounted horizontally rather than just vertically and why does it have to be mounted at least 300mm from the main meter box? ANSWER:  Due to the way the PowerwoRx is assembled internally, the ideal mounting orientation is vertically (as instructed in the Installation Instructions) with the wires coming out the bottom. Continental Power allows a horizontal mounting orientation with the cover on the top side and the wires coming out on the right.  In addition, the 300mm requirement is being removed from the installation instructions.

 

5.  If a home or small business has two 60-amp main panels, does a PowerwoRx e3 need to be installed on both panels? ANSWER: Typically one unit is recommended for each 60A panel.  One reason you may want to only install one unit is if the boxes are located next to each other, and the total electrical usage is low – typically in the $200-$300 per month range.  If the electrical usage is well above this level or the panels are not side by side, the only way to adequately treat the panels and protect the attached appliances and electronics is to have a unit on each panel.  The PowerwoRx provides adequate treatment for typical home electrical usage, in other words for typical inductive loads.  If the electric bill is quite high – over $500 per month, a single PowerwoRx will not provide the expected results.

 

 

3. How long will the PowerwoRx e3 last? »

3. How long will the PowerwoRx e3 last?

 

It has a predicted lifespan of over 20 years and comes with a 10-year warranty.  This claim is based upon the synergy between the three components which protect each other and lessen the de-rating of components which is typical in “capacitor in a box” type products. Units installed in1993 are still operating today.

 

4. What is the PowerwoRx e3 Warranty? »

4. What is the PowerwoRx e3 Warranty?

 

The warranty on PowerwoRx e3   is the best in the industry – a full 10 year! The patent pending design and the quality of the components used in the PowerwoRx e3   Whole House Energy Management System lets us offer this industry leading warranty.  No other manufacturer comes close.  Even if the PowerwoRx e3 performs as it should in the event of a lightning strike nearby, and the Industrial rated MOV’s which absorb the energy sacrifice themselves, Continental Power will repair or replace the unit.

 

In addition, a $25,000 warranty on the homeowners appliances AND electronics is included!  For more details on this warranty see the policy at www.iconicpowerworx.com.au website. It should be noted that the PowerwoRx only protects against surges on the electrical lines, not on the Telephone or TV Cable. For 100% protection Telephone and Cable surge protectors are needed.

 

Note:  The $25,000 warranty on the homeowners appliances AND electronics applies to the residential PowerwoRx e3 only. A PowerwoRx e3 installed in a commercial facility is not covered. The commercial 3-phase PowerwoRx have the same industry leading 10-year product warranty, but do not have the appliance/electronics warranty. This is not a liability insurance policy. The PowerwoRx, along with all products offered by Continental Power are insured by a multi-million dollar manufacturer’s liability insurance policy.

5. How much current will the PowerwoRx e3 handle? »

5. How much current will the PowerwoRx e3 handle?

 

The PowerwoRx e3   is designed for 240V and 60A which is typical for residential applications.  The PowerwoRx cannot be damaged if used on an application which would be better served by a larger unit.  The only down side would be the inability to store as much reactive current required for the motors being used, which means that current must come from the utility. In addition, where harmonic filtration is needed for larger “Commercial” applications, a line of 3-Phase Commercial PowerwoRx e3   units is available through Continental Power.

 

 

6.Will the PowerwoRx e3 affect any of my appliances and their normal use? »

6. Will the PowerwoRx e3 affect any of my appliances and their normal use?

 

No, if anything, your motors will run about 10% cooler, which is good because heat is the enemy of a motor.  PowerwoRx e3 reduces I2R line losses which improves voltage stability, improving motor performance.

 

 

7. Is the PowerwoRx e3 tested and approved by independent labs? »

 

8. How much can I expect to save per month by using the PowerwoRx e3? »

8. How much can I expect to save per month by using the PowerwoRx e3?

 

That depends on many factors. The size of your home, the amount of inductive motor load, and the amount you are paying per kilowatt-hour for electricity, harmonic noise on your electrical lines, surge & spike issues, etc. Based upon customer feedback by far the majority of users are seeing a savings but it is important to point out that some users have seen no energy savings based upon initial power factor above 95%, low harmonics and other factors.

 

A few states have electric utilities which are beginning to penalize residential electric customers for poor power factor as implementing charges for peak demand.  In these locations the opportunity for savings by installing the PowerwoRx is increased significantly due to the PowerwoRx ability to eliminate Power Factor penalties and reduce peak demand.

 

 

9. How long will it take for the PowerwoRx e3 to pay for itself? »

9. How long will it take for the PowerwoRx e3 to pay for itself?

 

Looking strictly at Energy Savings the product can pay for itself within 2-4 years.  This of course depends on individual circumstances, number of appliances and age, electrical costs and usage patterns, the homes power factor as well as other criteria.  The other benefits can turn out to be the biggest benefit of all!  Consider Surge & Spike Protection, as well as the harmful effects of harmonic distortion.  These invisible but very real threats to all electrical appliances and electronics in the home can and will cause premature failure.  Considering the significant investment in these appliances and electronics, often totaling in the 10’s of thousands of dollars, the protection provided by PowerwoRx e3   could be the biggest money-savings benefit of the product.

 

 

10. Is the PowerwoRx e3 easy to install and who is qualified to perform the installation? »

10. Is the PowerwoRx e3 easy to install and who is qualified to perform the installation?

 

Yes, but the PowerwoRx e3 must be installed by a licensed electrician. Qualified installers can be HVAC contractors.  It is ultimately the responsibility of the Continental Power distributor to insure the installer is qualified. Continental Power does not evaluate installers as to their qualifications and only in the event of a warranty claim will the qualifications of the installer be questioned.  If the installer is determined to not be qualified based upon local standards, and the product failure is attributable to improper installation, the product warranty will be void. We suggest that you contact the Master Electrician Association

 

Installation requires opening up of the electrical panel, exposing potentially dangerous high voltage wires.  The unit comes with complete installation instructions and installs in about 30 – 45 minutes as long as there is space to add a 6A or 10A single pole breaker.

 

 

Why haven’t I heard of these products until now? »

 11. Why haven’t I heard of these products until now?

 

That’s easy; two words “cost effectiveness”. Up until recently, electricity rates throughout AUSTRALIA were cheap, costing us 12 or 14 cents per kilowatt-hour. Now, electric rates are above 25 cents per kWh for residential and still rising. At the cheaper rates the PowerwoRx e3 was a long time return on investment, but at the current rates, it makes all the sense in the world today. These power conditioning products have been available to industry for many years.

 

 

12. What about PowerwoRx e3 for Surge Protection? »

12. What about PowerwoRx e3 for Surge Protection?

 

One of the most important features of the PowerwoRx e3   is the ability to protect the entire home against power surges. No longer is there a need for so many individual surge protectors in the home. The PowerwoRx e3 provides a broad range of protection for hardwired appliances and most home electronics such as appliances, televisions, satellite equipment, entertainment systems, etc using Industrial-Rated MOV’s. The unit protects from power line surges as well as spikes caused by internal wiring problems, loose connections and fluctuating demand from large motors such as vacuum cleaners, heating and cooling equipment, etc.

 

 

13. Is the PowerwoRx e3 Energy Star rated? »

13. Is the PowerwoRx e3 Energy Star rated?

 

PowerwoRx e3 is not Energy Star rated because this type of product does not fit into the Energy Star rating system.

 

 

14. Does the PowerwoRx e3 save any energy on Resistive (non-motor) loads? »

14. Does the PowerwoRx e3 save any energy on Resistive (non-motor) loads?

 

Resistive loads are equipment like incandescent lighting, electric resistant heating, electric hot water heaters and electric ovens and ranges.  These devices require no “magnetic power” or “reactive power” to operate; consequently they have no negative impact on Power Factor.  The energy savings capability of PowerwoRx e3   is achieved by storing the reactive power which is typically wasted, and making it available for reactive loads as required.  There is no energy savings from PowerwoRx e3   being attached to a purely resistive load.

 

 

15. Can the PowerwoRx e3 cause my electric bill to go up, and does it use electricity when there is little or no power demand? »

 

15. Can the PowerwoRx e3 cause my electric bill to go up, and does it use electricity when there is little or no power demand?

The PowerwoRx e3   will not cause the electric meter to turn on its own. The product does not “Use” energy – it captures energy from reactive (motor) loads and then provides it back to the motors when they need it.

 

 

16. Mounting Considerations – what if the Residential Power Panel is flush-mounted in an exposed area? »

16. Mounting Considerations – what if the Residential Power Panel is in an exposed area?

The PowerwoRx e3   is designed to be SURFACE MOUNTED.  Even if the 60A Power Panel is recessed, the PowerwoRx e3   must still be surface mounted.  With about a meter of wire to tie into the power panel in the meter box, the PowerwoRx e3   can be mounted in a less obvious location.

 

 

17. What is the difference between PowerwoRx e3 and other “Energy Saving” devices in the market? »

17. What is the difference between PowerwoRx e3 and other “Energy Saving” devices in the market?

 

There are over a dozen manufacturers of products that “look” similar and make similar claims as PowerwoRx e3   regarding energy savings.  These products are in many cases less expensive so what is the difference?

 

The numerous “Power Savings Devices” on the market today consist of two electrolytic capacitors in a box. The PowerwoRx e3   contains:

 

  • 2 Electrolytic Capacitors
  • 2 Harmonic Filters
  • 2 MOV’s for Surge/Spike protection
  • Additional electronics

 

A comparison of the two products is like comparing a golf cart and a sports car.  They are both considered transportation, but the sports car has a lot more capability.  As far as the literature goes, we all know that companies make all kinds of claims.  The PowerwoRx e3   has:

 

1.  The best warranty in the business (10 years)

2.  A patent pending product developed by a team of MIT PhD’s with no other product like it in the market

3.  True Harmonic and Noise Filtration

4.  True Surge & Spike Protection thanks to Industrial MOV’s

5.  $25,000 warranty on connected appliances & electronics (see the end of this document).

 

PowerwoRx e3   is a premium product that has premium features.  Consequently there is no comparable product on the market today that combines all these features together.

 

 

18. Does the PowerwoRx e3 consume energy on its own? »

18. Does the PowerwoRx e3 consume energy on its own?

 

No.  The PowerwoRx e3   stores and supplies energy to the electrical appliances in the home, it does not directly consume electricity.  Consequently, if an amperage meter (current probe) is placed on the electrical lines leading to the PowerwoRx e3, a reading of 2.5-3 amps will typically be shown.  Even when no appliances are on, and therefore no electricity is being consumed, there will still be current flow showing on the current probe.  Most assume this translates into 400W of energy being “used” which on an annualized basis will cost the homeowner well over $100 per year at current electric rates.  The truth is the PowerwoRx e3   “uses” no energy.  This is easily proven by turning off all electrical loads and going to the Electric Meter Box and reading the consumption – the meter will not be turning.

 

Another interesting test is to power a typical motor load like a bench grinder.  Use a current meter to measure the inrush current at start-up as well as the steady-state current draw with and without the PowerwoRx e3   in the circuit.  With PowerwoRx e3   activated the current draw at start-up and steady-state is typically reduced by over 30% thanks to the storing of the reactive energy by the PowerwoRx e3.

 

 

19. What authorized company is selling the PowerwoRx e3 in Australia? »

19. What authorized company is selling the PowerwoRx e3 in Australia?

 

Continental Power and its President Ed Kimmel has been a Power Conditioning solutions provider for over 19 years. Continental Power owns the intellectual property for PowerwoRx and there is only one way to obtain the original PowerwoRx brand, and that is through an authorized Continental Power Distributor in Australia –Iconic Energy Solutions 1300 133 396

 

 

20. Some Power Company Representatives have said Power Factor Correcting devices do not result in savings on the customer’s electric bill – why? »

20. Some Power Company Representatives have said Power Factor Correcting devices do not result in savings on the customer’s electric bill – why?

The following response was provided by Ed Kimmel, President of Continental Power:

 

I have nineteen years worth of data that I have shared with many engineers that have made the same statement as above.   I can tell you with 100% confidence that our systems do reduce kWh and kW usage as well as reduce or eliminate power factor penalties and reduce harmonic distortion.

 

As you know, no two electrical systems are the same, and no two utility companies bill their customers exactly the same.  There are electric utility companies that charge more for kW and kWh usage than others.  There are electric utility companies that penalize a customer for poor power factor.  We see much larger reductions in usage in less efficient electrical system.  This is to be expected.  We also see shorter payback periods and larger ROI’s on electric utilities with higher rates than others.

 

Power factor is just one third of the technology incorporated in the PowerwoRx Systems.  We also install PowerwoRx for noise reduction and protection, using MOV’s for surge and spike protection and harmonic filtration for noise reduction.

 

In my nineteen years of installing our equipment I have never had a dissatisfied customer.  This I have done by being honest and upfront with every customer I have had. We do reduce kW and kWh usage!

 

Ed Kimmel, President

Continental Power Corporation

 

Most Power Companies do not charge a penalty for poor power factor.  Some states are currently charging a residential Power Factor penalty.  Regardless of power factor penalties, PowerwoRx can and does save energy, but is important to understand that the amount of saved energy is dependent upon an almost infinite number of factors so being able to predict what the savings is not possible.

 

Some of the factors which can lead to power savings beyond reducing reactive current by improving power factor include reductions in harmonicas as well as surges & spikes.  Feedback from customers has shown that the majority of homeowners are seeing a savings on their electric bill, which is beyond the benefits provided by increased equipment life from reduced harmonics and surge and spike protection.

 

 

21. Can PowerwoRx e3 be mounted on the outside of the building? »

21. Can PowerwoRx e3 be mounted on the outside of the building?

 

The standard PowerwoRx e3   case is a NEMA 1 and therefore cannot be mounted outdoors or where exposed to moisture.

 

For exterior mounting order the PowerwoRx mounted in a NEMA 3 enclosure.

 

 

22. Will PowerwoRx e3 affect X10 lighting control systems, or Telephone or TV signals that are sent over the AC line? »

22. Will PowerwoRx e3 affect X10 lighting control systems, or Telephone or TV signals that are sent over the AC

line?

 

Considering the Harmonic and Noise Filtration technology used in the e3, this is a good question.  Continental Power Corporation has found that the harmonic filtration capability of the e3 WILL cancel out the X10 and other control signals generated to communicate over the AC line.  Other systems include UPB (Universal Power line Bus), CEBUS, Insteon and LONWORKS to name a few. Consequently PowerwoRx e3 should not be used in buildings where the AC line is being used to transmit lighting control, telephone, TV or any other signal.  A special PowerwoRx may be available in the future which has the harmonic filtration removed.  For now, contact customer support and request a custom unit with the filters removed.

 

Note that most new control systems are no longer using power line data transmission.  This includes Insteon although they still provide downward compatibility with X10 if necessary.  The PowerwoRx will have no impact on radio frequency (RF) control signals.

 

 

23. How can the PowerwoRx e3 provide the exact amount of capacitance to correct the Power Factor in every home? »

23. How can the PowerwoRx e3 provide the exact amount of capacitance to correct the Power Factor in every home?

 

Understanding that the ideal power factor is 1, and that poor power factor makes for an inefficient electrical distribution system which translates into higher kVA as well as higher KWh. A common question is “how can this device work in every home”?  Some companies promote having an electrician come out to a home, measure power factor and then create a custom unit designed for that home.

 

There are several reasons such a process is not recommended:

 

1.   The power factor will vary depending upon what appliances are running at any given time.  If the goal is to measure power factor, what appliances should be turned on?

 

2.   Years of experience have shown that the configuration of PowerwoRx provides the optimum solution for the majority of homes.  To produce a custom solution adds significant cost and provides little if any payback.

 

3.   Some are concerned that adding too much capacitance will put the home into a lead condition (where the current waveform will lead the voltage waveform). Again, this will be dependent upon what appliances are running at any given time.

 

 

 

24. What meter can be used to verify Power Factor and the other parameters required to evaluate my electrical system? »

24. What meter can be used to verify Power Factor and the other parameters required to evaluate my electrical system?

 

There are dozens of meters on the market.  At the high end are meters like the Fluke model 435 that sells for $7000+. Continental Power recommends a simple and basic Power Clamp Meter manufactured by Extech (P/N 380976) that includes the ability to measure Power Factor.  This meter are available several on-line merchants including http://www.tequipment.net/Extech380976.html.

 

Continental Power also recommends the Fluke 1735.  For more information go to: http://www.transcat.com/Catalog/ and search on the Fluke model 1735

 

 

25. Some customers using other “Energy Savings Devices” or basic capacitors in a box of which there are a dozen products like this, have not experienced any energy savings. Does this mean we will not see any energy savings with the PowerwoRx e3? »

25. Some customers using other “Energy Savings Devices” or basic capacitors in a box of which there are a dozen products like this, have not experienced any energy savings. Does this mean we will not see any energy savings with the PowerwoRx e3?

 

Typical “Energy Savings Devices” on the market contain capacitors which place 30 micro farads on each phase, potentially over correcting the system in many cases. The advantage of the PowerwoRx e3 is the “synergy” of the 3 elements; surge and spike protection, harmonic filtering, and energy savings. These synergies are vital together. The biggest difference between the other devices and the PowerwoRx e3 is line conditioning. By cleaning up the power the motors are more efficient and not as wasteful. Competitor’s products overcorrect and in some cases no savings are realized. In these cases installing a PowerwoRx resolved the problem. In no cases have we experienced a customer’s electric bill going up due to the addition of capacitance. There have been instances where a customer was saving energy and then added a swimming pool and another unit was added to compensate, but never the other way around.

 

Here is an excerpt from a university about using capacitors to increase power factor:

 

“Adding too much capacitance can push the system from “lagging” to “leading”; for example, adding too much capacitance may change the power factor from 95% lagging to 95% leading.  Although leading power factor does not harm equipment, purchasing excess capacitors is expensive and serves no useful purpose.  In addition, some meters may read a leading 95% power factor as 95% lagging.  If so, you would not get credit for the power factor correction from 95% to 100%. (Other utility meters would read a power factor of 95% leading as 100%).  Because of these reasons, we recommend a conservative approach to power factor correction in which we never overcorrect the power factor past 100%”.

 

 

26. Does PowerwoRx e3 protect me from all Surges and Spikes? »

26. Does PowerwoRx e3 protect me from all Surges and Spikes?

 

PowerwoRx e3   provides protection from Surges and Spikes coming in on the main power line, as well as internal threats such as those originating on a branch circuit.  Although electrical appliances and electronics in the branch circuit where the surge or spike originated are exposed, once it reaches the main power panel where the PowerwoRx e3   is connected the surge or spike will be arrested.  Considering there are typically 15-20 branch circuits in a typical home, the risk exposure is minimal.

 

It should be understood there are two additional paths which a surge or spike can enter the home from which are NOT protected by the PowerwoRx e3.  These two paths are your cable service and your phone service.  The only way to protect a“surge back feed” through cable and phone wiring is to provide surge protection on all three sources of entry that includes your electrical system, cable system and phone system. Cable and Phone surge suppressors are available from most electrical suppliers.

 

 

27. What causes power line surges? »

27. What causes power line surges?

 

Surges can be classified as external and internal. External surges are generally more severe than internal surges while internal surges generally occur more frequently (about 80% of all surges are internal). External surges are frequently caused by storms and normal power company switching operations. Internal surges occur when equipment within the building is cycling on and off.

 

 

28. How often do surges occur? »

28. How often do surges occur?

 

Very large surges occur infrequently (from a few times a year in medium exposure areas to 40 times a year in high exposure areas) since they are mainly storm induced (lightning and temporary interruptions due to storm damage), but surges over 1000 volts may occur many times a day since they are caused by normal equipment operation.

 

29. Can PowerwoRx e3 help resolve issues with interruptions in electricity? »

29. Can PowerwoRx e3 help resolve issues with interruptions in electricity?

 

PowerwoRx is not a solution for brownouts or power interruptions which last more than a few milliseconds.  Many customers complain of these types of power issues and the only solution for insuring an uninterrupted supply of electricity is a UPS, or uninterruptable power supply.  These devises are much like what is used to power computers, just much bigger.  The PowerwoRx would be able to help resolve issues with harmonics, noise, surges or spikes, but the PowerwoRx cannot help with power dropouts that last more than 2 cycles or 1/30th  of a second.

 

It should be noted that the major risk in a power dropout or brownout condition is when the power comes back on.  At the point at which power is restored, all inductive loads come on at the same time, creating damaging power spikes and distortion (noise and harmonics).  The PowerwoRx provides protection for this damaging condition.

 

30. How can PowerwoRx e3 help reduce surges and spikes if it is merely connected to the panel and only has 12 gauge wiring? »

30. How can PowerwoRx e3 help reduce surges and spikes if it is merely connected to the panel and only has 12 gauge wiring?

 

The surge & spike protection is accomplished by a device called an MOV (Metal Oxide Varistor). When the voltage rises significantly above the rated voltage (+20%), the MOV turns on and the voltage is shunted to ground, insuring the system doesn’t see the spike or surge.  By definition this is considered a spike arrestor.  The other components in the PowerwoRx, the harmonic filters and electrolytic capacitors act as suppressors by capturing the small surges and spikes that come down the line.

 

Confusion often occurs because logic would say that the unit should be connected in series like a fuse or breaker, so when there is a surge or spike the PowerwoRx would open the line.  This line of thinking is logical but that is not how this device or others like it operate.

 

Regarding the 12 gauge wiring, logic would also say that no wire that small could handle 40,000 amps (max rating of the PowerwoRx).  What needs to be understood is the rating is based upon a very short spike, literally milliseconds in length which is occurs in a lightning strike.  The product cannot handle a sustained over voltage but such occurrences are extremely uncommon.

 

31. Can PowerwoRx e3 be used with a back-up power generator? »

31. Can PowerwoRx e3 be used with a back-up power generator?

 

Back-up power generators are becoming more and more common in home applications as well as commercial, often run off propane or natural gas as a protection for power outages.  PowerwoRx is an excellent addition to a system which incorporates a back-up generator for several reasons:

 

  • In the switchover process which is typically automatic, as the generator comes on line and the relay which connects the generator to the main panel is closed, typically a spike in power is induced. The PowerwoRx e3 will clamp this spike, thereby protecting appliances and electronics.

 

  • Power supplied by back-up generators is typically not clean – meaning the noise and harmonic content is high.  The PowerwoRx e3 will reduce the overall noise and harmonics.

 

  • Back-up generators are typically not sized to run all appliances.  In some instances loads will exceed the rated output.  PowerwoRx reduces KVA demand from the generator by supplying the reactive power to inductive loads. This means that a customer can realize additional capacity from their generator they would not have had without PowerwoRx e3.

 

  • PowerwoRx will help to reduce I2R losses when powering inductive loads.

 

  • One note of caution:  Most back-up generators are connected to a sub panel which powers a select group of circuits so as to not overload the generator.  The installing electrician must take this into account.  If the PowerwoRx e3 is placed on the main panel and a contactor to isolate a sub panel for back-up power loads is used, the PowerwoRx e3 will not be connected when the generator is engaged.

 

  • In no way will there be any detrimental effects to either the PowerwoRx e3 or the generator.  We highly recommend the PowerwoRx e3  for emergency backup generator applications.

 

 

 

32. Can PowerwoRx e3 be used with Solar Panel/Wind Turbine installations and/or Reverse Metering? »

32. Can PowerwoRx e3 be used with Solar Panel/Wind Turbine installations and/or Reverse Metering?

PowerwoRx e3 is an excellent addition to any solar panel/wind turbine installation regardless of the configuration including the use of Reverse Metering (where electricity is fed onto the grid by the user).  Some common configurations are:

 

  • Solar or wind is used to supplement the systems energy needs
  • Solar or wind is connected to the grid via a bi-directional electric meter (Reverse Metering)
  • The system is off grid and relies on 100% solar energy for all the energy needs
  • All three of the PowerwoRx technologies benefit a system which incorporates solar and wind energy generation:
  • Surges & spikes are more frequently internally generated than external.  Solar Power Center protection is accomplished by a device called an MOV (Metal Oxide Varistor). When the voltage rises the PowerwoRx prevents the spike from potentially damaging the expensive electronics including the Inverter.
  • Harmonics are more prevalent in a solar generated power system due to the nature of how the AC waveform is created by the Inverter.  These Harmonics waste electricity, and are damaging to appliances and electronics. PowerwoRx significantly reduces Harmonics and Noise in the system
  • Improved Power Factor translates into reduced I2R losses, increasing system capacity and reducing energy use.

 

 

33. If the PowerwoRx is hit with such a large spike that it sacrifices itself, will the electricity still be on? Is the home still protected? »

33. If the PowerwoRx is hit with such a large spike that it sacrifices itself, will the electricity still be on? Is the home still protected?

 

The PowerwoRx is connected in parallel (not like a fuse which is in series) so in no case will the supply of electricity to the home be affected.  If the home is hit with a surge & spike of great magnitude like what would occur from a lightning strike in the area, and the PowerwoRx e3 sacrifices itself, the result is the PowerwoRx will no longer be operational.

 

This is indicated by:

 

1.   One or both lights will no longer be lit.

2.   There is typically a strong smell of a damaged electrical device.  This is normal and indicates the unit has sacrificed itself in order to protect your homes electronics and appliances.

 

In either case it is just as if the PowerwoRx had been disconnected from the panel, meaning the home will no longer be completely protected or a replacement unit should be ordered immediately.  Remember, PowerwoRx carries a 10-year warranty, and the only limitation is the product must be installed by a licensed qualified electrician.

 

 

34. What happens if a lightning spike comes into a building through a window air conditioner or some path other than the electrical line? »

34. What happens if a lightning spike comes into a building through a window air conditioner or some path other than the electrical line?

 

Surges and spikes often come through paths other than the main incoming electrical line. The PowerwoRx is effective at arresting these surges and spikes but the owner must realize that the surge or spike must reach the PowerwoRx.  This means that any electrical appliances or devices on the branch circuit where the surge or spike originates will potentially be damaged since they are located before the PowerwoRx.  For this reason point-of-use surge suppressors should be incorporated on very costly or sensitive electronics.

 

 

35. When a Demo Case is being used in a home with PowerwoRx Installed, why does the meter still show the same as before the PowerwoRx was installed in the home? »

35. When a Demo Case is being used in a home with PowerwoRx Installed, why does the meter still show the same as before the PowerwoRx was installed in the home?

 

The PowerwoRx Demonstration Case is an excellent way to show exactly what the PowerwoRx is doing with regards to a motor load.  When first turning on the demo case we see that the current coming to the case (what we call the SUPPLY side) is the same as what is going to the motor (LOAD side).  Once the PowerwoRx in the case is turned on, the current coming into the case (supply side) drops, yet the current going to the motor (load side) is the same.  This is because on every cycle of the AC waveform, literally 60 times per second, the PowerwoRx is storing reactive current and supplying it to the motor when it needs it.  In essence the PowerwoRx is recycling energy which otherwise would have been wasted.  When then the PowerwoRx in the demo case was turned off, the PowerwoRx in the home was storing this reactive energy and supplying it back to the motor.  Since the motor always received the current necessary to run, approximately 1.2A, the meters don’t show any signs of a PowerwoRx in the home.  A person would have to go back to the 200A electric panel and take an inductive current meter around the incoming power line at the top of the panel to see the effects of the PowerwoRx mounted in the home.  This is a typical method to show that the PowerwoRx is not only working, but is having a very positive effect. But when the PowerwoRx is turned on in the demo case, now the PowerwoRx closest to the load takes over the responsibility to store and supply (recycle) the otherwise wasted reactive current, which is why we see a drop in the current in the demo case.  Even if a home 5 PowerwoRx installed it would be the same, because the PowerwoRx in the case will always be the closest and therefore it will always be the device to recycle the current.

 

 

36. The electrician who installed our PowerwoRx tested the electrical system and said the PowerwoRx is making no difference in the current being used. How can I verify the PowerwoRx is operating? »

36. The electrician who installed our PowerwoRx tested the electrical system and said the PowerwoRx is making no difference in the current being used.  How can I verify the PowerwoRx is operating?

 

Adding capacitance will always change the amount of current coming into the electrical panel as long as there is at least one inductive load turned on.  With inductive loads activated, the Power Factor will always change and there is never a case where the amount of current being drawn from the utility or generator will stay the same.

 

The confusion is typically where the measurements are made.  A common mistake is placing the clamp meter around the wires going to a load like an air- conditioner.  As the previous question details, the current on the load side will always be the same.

 

We suggest the installer verify PowerwoRx is properly operating.  By reading the current being drawn on either L1 or L2, and then switching the PowerwoRx on and off will show a difference in current.  The percentage difference between current draw with PowerwoRx on and PowerwoRx off is dependent on initial Power Factor and the number of inductive loads.

 

 

37. How to determine if the PowerwoRx e-3 is working properly? »

37.  How to determine if the PowerwoRx e-3 is working properly?

 

Using a typical current clamp meter measure the current going to the RED and BLACK wires on the PowerwoRx unit.  An installed and operational PowerwoRx e3 unit should “draw” (but not consume) approximately 2.75 amps.  Another way to show proper operation is using a Power Factor meter on the lines feeding the panel which the unit is installed.  With inductive loads connected to the panel and running, turn the units breaker on and then off.  You will see the overall current drop with the unit on due to a reduction in reactive current. You will also see the Power Factor (PF) increase with the unit on and decrease with the unit off.   Be aware that if little or no inductive loads are operating when doing this test, the meter may show what appears to be a decrease in Power Factor.  If you look closely at the meter, you will see that the Power Factor display is showing that the PF went from lagging to leading.  We suggest turning on some inductive loads so the PF stays lagging but shows an increase.

 

It is important to remember that Power Factor measurements are a “snapshot” in time.  On a residence, don’t be looking for the PF to go from 78% to 96%.  The PowerwoRx e3 has a fixed amount of capacitance based upon average consumption for a typical 200A residential application.  From studies of many homes, we know the PowerwoRx e3 will raise the average PF to approximately 95%.  Some electricians have voiced concern that during their measurements, the Power Factor rose up only 5 or 10% and is still below 90%.  Again, this is a snapshot, and in most cases the measurement was taken with the majority of inductive loads turned on.  Our goal when using a Current Meter/Power Factor Meter to validate that the unit is working and to show the customer that when the unit turns on the current drops and Power Factor goes up.  The amount of decrease/increase is inconsequential for the purpose of the test.

 

 

38. What does the number on the e-CoMeter indicate regarding noise and harmonics? »

38. What does the number on the e-CoMeter indicate regarding noise and harmonics?

 

The e-CoMeter has been developed by Continental Power to show the overall harmonic and noise level on the AC line.  The actual reading of 0-1999 does not correspond to any specific value such as volts or frequency, but should be considered a relative level of harmonics and noise.  By taking an initial reading, the distributor can show the building owner or occupant the current reading – the lower the number, the better power quality.  A good demonstration to the customer is to show what the current level is and then plug in a PowerwoRx e3 with a standard ‘B’ plug connected into the same outlet.  You will typically see a reduction of 60-90%.  If the meter reads 2—, or shows no numbers, the meter is in an “Over Range” condition, meaning the actual value is above the maximum displayable value of 1999.  In these cases the distributor should point out to the customer that the Noise and Harmonics are exceptionally high and action should be taken to protect their electronics and appliances.

 

 

Electrical Terms – Definitions

 

Alternating Current (AC) »

Alternating Current (AC)

 

The flow of electrons in a conductor measured in amperes. Alternating current reverses its direction of flow in a cyclical manner; i.e. 60 cycles per second. Conversely, direct current always flows in the same direction at 0 cycles per second.

 

 

Amperes (Amps) »

Amperes (Amps)

 

The unit measure for the flow of current in a conductor (analogous to litres per minute in a piping system).

 

 

Voltage (Volts) »

Voltage (Volts)

The measurement of the electromotive force or potential which will make electrons flow in a conductor or circuit.

 

 

Watt, Kilowatts, Kilowatt Hours »

Watt, Kilowatts, Kilowatt Hours

 

Electrical power consumption is measured in watts. A Kilowatt is 1000 watts. A Kilowatt Hour is 1000 watts used for one hour. We are concerned with true power which is the measure of power actually used by the load as measured by the utility watt meter and our T.I.F. meter. In pure resistive A/C circuit, power could be calculated by measuring the voltage across the phase conductors and multiplying by the current flowing through the circuit conductors with an amp meter. To measure true power in inductive circuits, power factor must be considered.

 

 

KVA (Kilovolt Amperes) »

KVA (Kilovolt Amperes)

 

KVA is the non power measure of the voltage multiplied by the amperes. KVA is not a measure of true power it is a measure of the level of apparent power a generator or transformer could deliver to a circuit with a power factor of one. To convert from apparent power to true power, you must take the KVA and multiply it by the power factor. For example, 100 KVA of measured apparent power serving an inductive load with a power factor of .9 would result in a real power of 90 KW. If Kilowatts (KW) is the measure of true or real power available for work then KVA is a measure of apparent power needed to get the true power to the work. From a utility’s point of view they are generating power with a power factor of one. In other words the KW and KVA at the outlet of the power plant is the same value. As the power factor is degraded by load and transmission factors it takes proportionally more KVA per KW used to create and deliver to the consumer true or USABLE power. The effect that a lagging power factor has on the utility is then to force it to generate more apparent power to satisfy our clients’ needs for true or USABLE power. In other words, if we measure a power factor of 1.0, then each KVA is being turned into a KW and the real and apparent power are equal. If the power factor is .5 then each KVA supplied to the transformer by the utility results in one half of one KW of real power being consumed and measured. This means the utility has to absorb the difference in real vs. apparent power. The affect on the utility supplying power to a network of customers with lagging or poor power factor is that its generating and distribution efficiency is reduced. Because the current being generated by the utility has to increase as the demand for KVA increases and in a poor power factor network the current increases disproportionately faster than in a network with unity power factor, then the losses due to the resistive heating in the power distribution network of conductors increases.

 

The term most frequently used to express this problem is W=I2   R meaning that conductor, transformer and motor heating increase at the rate of the amperes squared time the resistive component of the circuit. Some customers are penalized for low power factor by being charged for the difference between KVA and KW. PowerwoRx e3   reduces the I2   R losses by improving power factor and reducing KW.

 

 

KVA(R) »

KVA(R)

 

The measure of the amount of reactive KVA that is necessary to raise a lagging power factor toward unity.

 

 

Harmonic Interference »

Harmonic Interference

 

AC power is delivered throughout the distribution system at a fundamental frequency of 60 Hz. (50 Hz in Europe.) Harmonics are defined as, “integral multiples of the fundamental frequency.” For instance, the 3rd harmonic frequency is 180 Hz, the 5th is 300 Hz, etc. In the US, the standard distribution system in commercial facilities is 208/120 wye. There are three phase wires and a neutral wire. The voltage between any two phase wires is 208, and the voltage between any single phase wire and the neutral wire is 120. All 120 volt loads are connected between a phase and neutral. When the loads on all three phases are balanced (the same fundamental current is flowing in each phase) the fundamental currents in the neutral cancel and the neutral wire carries no current. When computer loads and other loads, using switched mode power supplies, are connected, however, the situation changes.

 

Switch mode power supplies draw current in spikes, which requires the AC supply to provide harmonic currents. The largest harmonic current generated by the SMPS is the 3rd. The magnitude of this harmonic current can be as large as or larger than the fundamental current. Also generated, in smaller amounts, are the 5th, 7th, and all other odd harmonic currents. Like the fundamental current, most harmonic currents cancel out on the neutral wire. However, the 3rd harmonic current, instead of canceling, is additive in the neutral. Thus if each phase wire were carrying, in addition to fundamental current, 100 amps of 3rd harmonic current, the neutral wire could be carrying 300 amps of 3rd harmonic current. In many cases, neutral-wire current can exceed phase wire currents. This extra current provides no useful power to the loads. It simply reduces the capacity of the system to power more loads, and produces waste heat in all the wiring and switchgear. When the 3rd harmonic current returns to the transformer it is reflected into the transformer primary where it circulates in the delta winding until it is dissipated as heat. The result is overheated neutral wires, switchgear, and transformers. This can lead to failure of some part of the distribution system and, in the worst case, fires. In addition, waste heat in all parts of the system increases energy losses and results in higher electrical bills. 3rd harmonic currents can increase electrical costs by as much as 8%.

 

 

Circuit »

Circuit

 

A closed loop consisting of conductors (wires) from a source of voltage (a transformer in our case) to a load (motors, fluorescent lamp ballasts or resistive loads) that provides the path for the flow of current through the load.

 

 

Phase »

Phase

 

Phase is a trigonometric measure of the angle between the 60-cycle wave current form and the 60-cycle voltage wave form. In a perfect world, the current wave form and the voltage wave form leaving a generator would start at the same time. In reality, the inductive characteristics of the electrical distribution system and the inductive loads imposed on it retard the current wave form and cause it to lag the voltage wave form.  If a circuit had more capacitance then inductance, the current wave form would lead to the voltage wave form.

 

 

Inductive Load »

Inductive Load

 

In general loads that operate by the passing of alternating currents through a coil of wire wound around an iron core.

 

The resulting magnetic field is used to:

 

a – cause a motor shaft to rotate, or

 

b – induce a similar current in another coil of wire wound around the same piece of iron core as in a transformer

(There are inductive heaters that are coils of wire wound around the media to be heated.)

 

 

Resistive Load »

Resistive Load

 

A load that turns all energy (current and voltage) applied to it into heat. Includes incandescent lamps, space heaters, immersion heaters, etc. These loads are not inductive.

 

 

Power Factor »

Power Factor

 

When current and voltage wave forms start at the same time they are in phase and power factor is 1. As circuit inductance retards the current wave form it falls out of phase or lags the voltage wave form. The measure of a lagging current wave form is expressed as a percentage; i.e., if the current lags the voltage by 10%, the power factor is 100% less 10% or 90% or 0.90.

 

Effects of low power factor:

 

It is sometimes considered that the watt-less component of a current at low power factor is circulated without an increase of mechanical input over that necessary for actual power requirements. This is inaccurate because internal work or losses due to this extra current produced and must be supplied by the utility. Since these extra losses manifest themselves in heat, the capacity of the distribution network is reduced. Moreover, wattless components of current heat the line conductors, just as do energy components, and cause losses in them.

 

The loss in any conductor is always:  W=I2R

 

Where W = the loss in watts, I = the current in amperes in the conductor, and R = the resistance in ohms. It requires much larger equipment and conductors to deliver a certain amount of power at a low power factor than at a power factor close to1.

 

An excellent document is available from the Department of Energy describing the importance of Power Factor and how improving power factor can reduce electrical costs.

 

See http://www1.eere.energy.gov/industry/bestpractices/pdfs/mc60405.pdf

 

 

Capacitance »

Capacitance

 

Is a measure of a circuit or device’s ability to store electrical energy. Applied primarily to A/C circuits where the alternating nature of the current charges and discharges the capacitor as the current reverses its direction of flow in the circuit.

 

Capacitors ability to store electricity is measured in “Farads” or increments thereof as in microfarads. Capacitors are used to improve the performance of certain inductive circuits as discussed under power factor.

 

 

Electro Magnetic Field (EMF) »

Electro Magnetic Field (EMF)

 

Technically, the term “electromagnetic field” (EMF) refers to all fields throughout the electromagnetic spectrum. In common usage, however, the term usually refers to so-called extremely low-frequency no ionizing radiation fields—those fields below 300 Hertz (Hz)—and often only to those fields in the 50 to 60 Hz range, which are also known as power-frequency EMFs. As a type of no ionizing radiation, EMFs in this range do not have sufficient energy to remove an electron from an atom or molecule, but generally transfer thermal energy to other particles. Power-frequency EMFs are those generated by electric power delivery systems—those for which there have been the greatest public concern and research about possible adverse human health effects.

 

Power-frequency EMFs have two components: electric fields and magnetic fields. The electric fields are generated from potential energy, or the presence of voltage on a power line. The magnetic fields, on the other hand, are generated from the actual electrical current, or the flow of electricity. Thus, when a standard household electric light is plugged into a live electrical socket, but turned off, it generates only an electric field. Once turned on, it generates both electric and magnetic fields, since the voltage is still present but current is now flowing. The size of a magnetic field increases as the amount of current flow increases, as the size of the source increases, and as one gets nearer to the source.

 

 

Metal Oxide Varistor (M.O.V.) »

Metal Oxide Varistor (M.O.V.)

 

A discrete electronic component that is commonly used to divert excessive current to the ground and/or neutral lines. Acting like a pressure relief value, an MOV is comprised of zinc oxide with small quantities of bismuth, cobalt, manganese and other metal oxides.

 

 

Mathematics Of Electric Power In Circuits »

Mathematics Of Electric Power In Circuits

 

Electric power, like mechanical power, is represented by the letter P in electrical equations. The term wattage is used colloquially to mean ‘electric power in watts. In direct current resistive circuits, instantaneous electrical power is calculated using Joule’s Law, which is named after the British physicist James Joule, who first showed that heat and mechanical energy were interchangeable.

 pvi

Where P is the power (watt or W) and V is the potential difference (volt or V) and I is the current (ampere or A)

For example:

2a

Joule’s law can be combined with Ohm’s law to produce two more equations:

pi2r

Where R is the resistance (Ohm or Ù).

For example:

2a6

And

12v

In alternating current circuits, energy storage elements such as inductance and capacitance may result in periodic reversals of the direction of energy flow. The portion of power flow that, averaged over a complete cycle of the AC waveform, results in net transfer of energy in one direction is known as real power (also referred to as active power). That portion of power flow due to stored energy, which returns to the source in each cycle, is known as reactive power.

 

 

Power triangle – The components of AC power »

Power triangle – The components of AC power

 

The relationship between real power, reactive power and apparent power can be expressed by representing the quantities as vectors. Real power is represented as a horizontal vector and reactive power is represented as a vertical vector. The apparent power vector is the hypotenuse of a right triangle formed by connecting the real and reactive power vectors. This representation is often called the power triangle. Using the Pythagorean Theorem, the relationship among real, reactive and apparent power is:

copentents of ac

(Apparent power)2 = (real power)2 + (reactive power)2

 

The ratio of real power to apparent power is called power factor and is a number always between 0 and 1.

 

Wild-leg or Red-Leg Delta or High-Leg Delta »

Wild-leg or Red-Leg Delta or High-Leg Delta

 

Wild-wire or red-leg delta properly referred to as high leg delta is a type of three phase transformer winding connection sometimes found in older electrical installations. A transformer wound in this fashion will have four wires coming out of the secondary: the three phases, plus a neutral that is a center-tap of one of the windings. The voltages between the three phases are relatively the same; however the voltage magnitudes between a particular phase and the neutral vary. The phase-to-neutral voltage of two of the phases will be half of the phase-to-phase voltage. The remaining phase-to-neutral voltage will be 1.7 times the phase-to-phase voltage. Typically, the transformer is designed such that the ‘B’ phase is the ‘high’ leg. According to Article 110.15 of the 2005 National Electrical Code, panel boards connected to this type of transformer must explicitly identify as the high leg, preferably by coloring it orange. Generally the high-leg cannot be used for loads requiring a neutral such as lighting because of the high voltage potential. In other cases such as three phase motors which do not utilize a neutral the wild-leg is irrelevant because it has the same phase to phase voltage potential as the other two legs.

 

It is important to identify systems with a wild leg as the PowerwoRx Commercial Y units cannot be used with these systems due to the MOV’s being connected from phase to neutral.

 

 

Variable Frequency Drives »

Variable Frequency Drives

 

(Sometimes abbreviated VFD) is electronic equipment that allows an electric motor to be run at varying rotational speeds. VFDs are frequently used to start large three-phase AC synchronous motors. These motors cannot be started simply by applying line frequency mains power; the rapidly rotating magnetic field would be unable to overcome the inertia of the rotor (and any connected load). Using a VFD provides one possible means to start these motors: the VFD will start using a low frequency that the rotor can follow, ramping up the frequency as the rotor accelerates. And unlike other starting methods, the VFD also allows very efficient speed control once the motor is running (simply by varying the ultimate frequency of the supplied power).

 

The most common type of packaged VF drive is the constant-voltage type, using pulse width modulation to control both the frequency and effective voltage applied to the motor load.

variable frequency

 

VFD Controller »

VFD Controller

 

Variable frequency drive controllers are solid state electronic power conversion devices. The usual design first converts AC input power to DC intermediate power using a rectifier bridge. The DC intermediate power is then converted to quasi-sinusoidal AC power using an inverter switching circuit. The rectifier is usually a three-phase diode bridge, but controlled rectifier circuits are also used. Since incoming power is converted to DC, many units will accept single-phase as well as three-phase input power (acting as a phase converter as well as a speed controller); however the unit must be de-rated when using single phase input as only part of the rectifier bridge is carrying the connected load.

 

As new types of semiconductor switches have been introduced, these have promptly been applied to inverter circuits at all voltage and current ratings for which suitable devices are available. Introduced in the 1980s, the insulated-gate bipolar transistor (IGBT) became the device used in most VFD inverter circuits in the first decade of the 21st century.

 

AC motor characteristics require the applied voltage to be proportionally adjusted whenever the frequency is changed in order to deliver the rated torque. For example, if a motor is designed to operate at 460 volts at 60 Hz, the applied voltage must be reduced to 230 volts when the frequency is reduced to 30 Hz. Thus the ratio of volts per hertz must be regulated to a constant value (460/60 = 7.67 V/Hz in this case). For optimum performance, some further voltage adjustment may be necessary, but nominally; constant volts per hertz is the general rule. This ratio can be changed in order to change the torque delivered by the motor.

 

The usual method used for adjusting the motor voltage is pulse-width  modulation (PWM). With PWM voltage control, the inverter switches are used to divide the quasi-sinusoidal output waveform into a series of narrow voltage pulses and modulate the width of the pulses.

 

Operation at above synchronous speed is possible, but is limited to conditions that do not require more power than nameplate rating of the motor. This is sometimes called “field weakening” and, for AC motors, is operating at less than rated volts/hertz and above synchronous speed. Example, a 100 hp, 460V, 60 Hz, 1775 RPM (4 pole) motor supplied with 460 V, 75 Hz (6.134 V/Hz), would be limited to 60/75 = 80% torque at 125% speed (2218.75 RPM) = 100% power.

 

An embedded microprocessor governs the overall operation of the VFD controller. The main microprocessor programming is in firmware that is inaccessible to the VFD user. However, some degree of configuration programming and parameter adjustment is usually provided so that the user can customize the VFD controller to suit specific motor and driven equipment requirements.

At 460 Volts, the maximum recommended cable distances between VFDs and motors can vary by a factor of 2.5:1. The longer cables distances are allowed at the lower Carrier Switching Frequencies (CSF) of 2.5 kHz. The lower CSF can produce audible noise at the motors. The 2.5 kHz and 5 kHz CSFs cause less motor bearing problems than caused by CSFs at 20 kHz. Shorter cables are recommended at the higher CSF of 20 kHz. The minimum CSF for synchronize tracking of multiple conveyors is 8 kHz.

 

 

VFD Operation »

VFD Operation

 

When a VFD starts a motor, it initially applies a low frequency and voltage to the motor. The starting frequency is typically 2 Hz or less. Starting at such a low frequency avoids the high inrush current that occurs when a motor is started by simply applying the utility (mains) voltage by turning on a switch. When a VFD starts, the applied frequency and voltage are increased at a controlled rate or ramped up to accelerate the load without drawing excessive current. This starting method typically allows a motor to develop 150% of its rated torque while drawing only 50% of its rated current. When a motor is simply switched on at full voltage, it initially draws at least 300% of its rated current while producing less than 50% of its rated torque. As the load accelerates, the available torque usually drops a little and then rises to a peak while the current remains very high until the motor approaches full speed. A VFD can be adjusted to produce a steady 150% starting torque from standstill right up to full speed while drawing only 50% current.

 

With a VFD, the stopping sequence is just the opposite as the starting sequence. The frequency and voltage applied to the motor are ramped down at a controlled rate. When the frequency approaches zero, the motor is shut off. A small amount of braking torque is available to help decelerate the load a little faster than it would stop if the motor were simply switched off and allowed to coast. Additional braking torque can be obtained by adding a braking circuit to dissipate the braking energy or return it to the power source.

 

 

VFD Applications Considerations »