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 find that on the control panel you can see the frequency drop and rise erratically.

Causes to investigate and then resolve

Machinery loads have 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 down stream equipment to ensure that are within the capacity of the generator output

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

Old Motor drives without electronic governor 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.etc..

Severely imbalanced load across phases, which increases and drops rapidly-
For example
Phase 1 Zero
Phase 2 100%
Phase 3 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 is a small device that sits on the alternator monitoring the power output. You may never even notice it.
The Automatic Voltage Regulator (AVR) is there to maintain constant voltage and power line conditioning to the equipment load under a wide variety of conditions, especially when the load on the generator could vary widely. The AVR smooth’s 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 the AVR fault or not.

Power Continuity can assist
Call us on 0845 055 8455


Search – Knowledge Base

Talk to Us: