Generator Frequency Fluctuation

Generator frequency fluctuation can occur when the generator is under load.

The diesel engine can he heard to be struggling or hunting randomly. If this audible fluctuation continues, you may see the frequency rising and falling erratically on the control panel.

Generator Frequency Fluctuation – Causes to investigate and then resolve

Machinery has suddenly started up and caused a wild spike load beyond the range of your generator. Your generator is struggling to cope. Check the generator size is correct. Then check the maximum spike load of your downstream equipment to ensure that they are within the capacity of the generator output.

Motor drives down stream going ON & OFF erratically, causing generator overload.

Old motor drives without electronic governors starting up, hitting the generator with a large power spike beyond the power range of the generator.

The load on the generator isn’t balanced and has increased recently, then dropped and back again etc.

Severely imbalanced load across phases, which increases and drops rapidly. For example:
Phase One: Zero      Phase Two: 100%      Phase Three: 10%

Fuel blockage or restriction.

Fuel pump – intermittent fault.

NO functioning AVR on the generator – Basic alternator/governor on an old generator , hence never had an AVR fitted.

AVR failure or intermittent AVR failure.

The AVR (Automatic Voltage Regulator) is a small device that sits on the alternator, monitoring the power output. You may never even notice it.
The AVR is there to maintain constant voltage and power line conditioning to the equipment load. This is done under a wide variety of conditions, especially when the load on the generator could vary widely. The AVR smooths out the constant power output of the generator.

Contact your generator supplier, who can send out an engineer with a laptop to log into your control panel. Once inside the software, he can determine whether this is an AVR fault or not.

Power Continuity can assist
Call us on 0845 055 8455


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