incompatiable avr changing

[bedane]

hi all
i am planning to change an obsolete stamford avr (series 3 part number 450-11700) with datakom product avr 8 automatic voltage regulator for old 250 kva cummin generator set. this is because we need the generator working as soon as possible and we dont have the compatiable avr at hand.(avr-8 can work with generator of this capacity)
the problem is that the stamford avr get the supply from the permenant magnet generator at the end of the alternator and sensing voltage from the main stator.but since the datakom avr dont support the permenant magnet generator i am planning to use the datakom avr without the permenant magnet generator out put connected with only the sensing from the main stator out put (which also used as supply for the avr) and by connecting the exitation terminal connected to the excitation out put of the avr.

Will it work properly?
best regards

 

[niallnz]

It should work, according to the Datakom AVR8 product specification it only needs 4VAC residual voltage on the stator start. The sense and power inputs are rated for full line to neutral voltage so you can connect them to the stator winding ends and not half way down the winding as the stamford is.

 

[waross]

I have replaced PMG AVRs with self powered AVRs until a proper replacement could be delivered. You lose the voltage stability that the PMG provides for motor starting and you may have protection issues under fault conditions. The generator will function as well as with the original AVR under normal, steady loads.
The PMG is an option that is often added to a generator that is suitable for use with a non PMG AVR.
However I have had issues with insufficient residual voltage when changing from one AVR to another economy AVR.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[bedane]

thankyou all
I have replaced the avr and it is working well.
best regards