Low Power Factor Values @ PLC and Field Instrumentation Power Supply


Thread Starter


A dedicated and classified control panel receive 480 VAC @60 HZ (Input) for provide power to all control systems (PLC, OIT, I.S. barriers, etc)and
some motor (One of 75 HP, 1 of 10 HP). The electrical measurement executed with electrical data logger installed on the three phase of the incoming power were the followings: Power Factor Range (.19 to .31), Harmonics (7th)=1.67 %.
Questions: Do the values mentioned above can affect PLC power and Instrumentation power supply performance?

Hakan Ozevin

It is already known that harmonics affect sensible devices, especially those having SMPS's. However, harmonic level you mentioned is very low.

I am not sure about mains power factor, however specifications for your devices should give enough advise I think.
The main affect of low power factor, is switching of your compensation capacitors, which may lead to resonate together with the inductance of distribution transformer with high level harmonic currents.

Hakan Ozevin