Regarding Power Factor Loss..?

Question

We are facing power factor loss in a dyeing mill it has dropped down from .85 to . 75 in past 3 months could you please give me a reason for the loss ? add. info: anyhow no machines were run for 3 months

Answer 1

Does “no machines were run for 3 months” mean that the mill is shut down and power is being used only for office lighting, air conditioning, ventilation etc? If that is the case, the air conditioning and ventilation equipment may have a lower power factor than the machines that are not running. The power factor for the entire facility is essentially the average of the individual loads weighted according to the size of the loads. If high power factor loads (or loads with attached pf correction) have been shut off, the remaining low pf loads will make the facility pf lower.

If the pf measurement method measures harmonic current as reactive current, harmonics caused by office equipment, light ballasts, etc. will reduce the power factor.

If the supply voltage has increased in the mill because of reduced load or if there is a higher voltage at the service entry from the utility, that will reduce the pf of any motors that are operating.

If any motors that are operating have experienced a load reduction, that would reduce the pf. That might include ventilation fans that have had the air flow cut back by dampers etc. Any pumps that are operating with flow reduced by control valves would also be operating at lower pf. Any machines that are operated unloaded for cleaning etc. would have a pf reduction.

Power factor correction capacitors may have fuses that have blown or the capacitors may have been taken off line in some other manner.

Answer 2

it almostly because of the need of the machine for extra electric current for field generation ,that is caused by the internal losses and deformation of the machine internally or by the leakage of materials within the rotor and the stator such cases cause the current to be more reactive than ever.

Answer 3

You don't mention what type of motor this is, which is important information.

Has the load dropped? Power factor will drop with load.

You call it a loss which I don't understand. Depending on your power consumption and agreement with you supplier, you may not be penalized for power factor and even if you are, its KVAr's you pay for so you have to factor in the power.