Question

hi!

very interesting problem. first, differentiate wether it is mechenical engine side problem or it is from alternator / avr side > Since, you have already replalced avr once, can you just check wether it is due to engine over speed ? or it is at the time of engine start cycle?

It is common with capacitors in the circuits, many times, due to transient over speed of the engine ( fly wheel inertia effect ) you observe high voltages of the order 500v. I have observed with even 160 kva engine. Just increase the trip time delay of the over voltage relay, keep at 2 sec. once speed establishes at steady rated speed, voltage will be normal & no trippings.

Then switch on the power breaker.

In respond to your answer, thats I have tried and it still the same,

Hi aishaamadumamamariama,

Try these;

While the engine is OFF

1. Adjust SLOPE fully clockwise and back a small bit.(to increase voltage drop).

2. Adjust STAB FULLY clockwise and back a small bit.(to increase response time,increase stability)

3. Adjust VOLT very small bit counter clockwise.

Start the engine

If same problem exist, put both SLOPE and STAB fully clockwise and start the engine (you can encounter either HI or LOW voltage then just make the small adjustment needed from VOLT potentiometer).

Please note: this exercise was not shown on the trouble shooting guide as REMEDY, but for sure it works,

I am using Volvo Penta and I am encountering that problem and can fixed it easily through that procedure, (in fact early this morning I also encountered that and I am thinking of due to some abnormal vibration, so I lock up the adjusting potentiometer with liquid white paper erasure. and it works.

Hopefully my input work helpful with you.

Kind regards

Roman

Hi Roman

Its makes sense, I will try it and get back to you ASAP

Kind regards

Aishabaisatu

Yours too but still the same