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Member Since 13 Aug 2009
Offline Last Active Aug 20 2009 10:12 AM

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Energy Saving Device, Power Factor Correction Type

13 August 2009 - 09:43 AM

Dear All,

I'm evaluating a Energy Saving Device (powerliner) based on power factor improvement. This unit manly consists of capacitors which are installed near the motor.

Already in this forum there is a lot mentioned about such units. Most of the savings consist of power line savings which is logical and can be explained.

The manufactor claims to have high savings, up to 5 or 6%. From my point of view, that's not realistic.

To do further investigation, we've done some measurements on a motor (application: water pump)

We've installed 2 measuring points. 1 at the power cabinet, 1 near the motor, just before the energy saver connection.
Normal measured load is appr. 150 kW. As expected we see a large variation in Q (kvar) but we see also a slight decrease in P (kW) power when the unit is switched on. Even near the motor we see a decrease of approximately 8 kW = 5%.

At this point we cannot explain this variation. It was not possible to do torque measurement on the motor shaft. But in generally, such a passive device can nog influence the motor output power, can it?

Does anyone know how to explain this variation, or has some experience with these type of devices?

Thanks for your answer,

Kind regards,