Generator Problem

that is a residual voltage in generator without avr, that is no need to replace the avr,

i'm a service engineer for the avr panel, for any doubt ask me

thanks, but with this residual voltage in the generator of around 600volts AC, is it safe to turn on the avr of the generator without harming it? we are apprehensive to turn on the avr since before, the residual voltage (avr off-state) was just around 90-110volts ac. will the avr control the gen voltage with this higher residual voltage?

please advice and once again thank you and much appreciated

I bet dollars to donoughts, that the lover voltage shows up only in no load condition. A few 10 kW load (lights, heater) drops it low. It is caused by the remaining magnetism in steel (both rotor and stator), but there is no real power in it. No need to bother the voltage regulator.

Once the test is done, do not forget to remove the temporary load, before going online.

got it! thank you guys. appreciated much

It sounds like it could be a transductor arrangement(see <http://accelconf.web.cern.ch/accelconf/p73/PDF/PAC1973_0360.PDF> ) or saturable reactor.

Briefly, one type of transductor is a transformer, single or multiphase which is designed to be able to put out excessive voltage.

Additional windings are then added which are controlled by an AVR. These windings introduce an additional current into the core to saturate the core and thus limit the output voltage to the desired level.

There are several different transductor configurations.

Check the battery in your digital voltmeter.

Our maintenance man was baffled by 260 VAC indicated from a 120VAC receptacle until someone else measured the voltage using a different voltmeter.

Isnt there supposed to be a bleeder resistor (high value) in that circuit somewhere to bleed off stray voltages? Seems like it got disconnected.