over voltage alternator.

What does the manufacturer say on this topic?

Firstly what is causing the alternator to go overvolts - usually this is due to bad setup of the governor failing to pull the energine speed back befor the overvoltage spike becomes an issue .

Rob

dear,

did you tried for folowing checks...

1. Check for Capacitors... Over capacitors at the starting of DG may cause over voltages

2. Check for Over speed... Generally over speed protection is provided in AVR, does AVR have this feature ?

3. Check for performance of AVR, if you find the over voltages while in normal operating conditions , ( most of the time, at specific % of load say 25- 35 % rated load )other wise dg runs properly, then design of AVR is not good & calls for replacement of AVR by better quality AVR.

You may provide over voltage relay in the panel, to prevent high voltages being fed to the load.

dear guru.

thank you for the information that you shared to me it helps a lot.

more power.

You might need to check the following:-

1- Excitation field circuit (AVR - Automatic Voltage Regulator) of your alternator, as the higher the field the higher the output.

2- Check the speed governor of the prime mover for over speed control.

3- Check the magnetic pickup sensor for correct installation and healthy signal to the speed governor.(in case this is a Diesel engine set)

4- Check your overload setting of your main CB ( could be over rating ).

5- I f you have more than one alternator connected on parallel , make sure that they are synchronized and no reverse power is happening which make one of them act as a motor.

Hope that of help to you.

Salem