Generator- Motor Operation

[Paulsont]

Our Generator is operating at 380V 60Hz and which is supplying to a 3 phase motor and name plate showing 380-420V, 50Hz. What will happen if the Generator and Motor frequency mismatch. And we also noticed, Right bank side of our Generator is creating white smoke and not taking load also RPM dropping etc.

We are using 1000kVA Cummins QST 30 model Generator.

 

[zeusfaber]

I'm not an expert on this - but someone who is will probably be along in a bit (it can take a while at the weekend). They are likely to ask questions like:

What sort of load is the motor driving (power Vs speed depends critically on this)
What speed was it (the load) designed to spin at?
Is the white smoke coming from the diesel end of the set or the generator end?
What scope have you got for turning up the AVR on the generator?

A.

 

[waross]

If the motor is rated 380-420 Volts at 50 Hz. To maintain the Volts per Hertz ratio at 60 Hz it will want to see
380V-420V x 60Hz/50Hz = 456V-504V. Those are delta connection voltages. Wye connected voltages will be higher.
Your motor is operating on a serious under voltage. At full load, the current will be above rated current and the motor will overheat.
Your motor shows a rated voltage of 440-480 Volts at 60 Hz.
The motor will perform the best if you run the voltage up to 480 Volts.
White smoke from a diesel generally indicates unburned fuel.
That indicates possible serious mechanical issues with the right bank.
Losing RPM under load is another sign of serious mechanical issues.
It may be a failed right side turbo, but it sounds more serious than that.
Possibly the cooling circulation to the right bank was impaired and the rings have been damaged.
Many years ago, I saw a small 15 KVA set run to destruction without oil.
The shop looked at the engine and then asked;
"What is your tax position?"
"What's that have to do with the cost of repairs?"
"Well if you are in a position to write the cost of repairs off your taxes, we can repair the engine for $4400. If you are not in a position to write the cost off taxes we can supply and instal a new engine for $4000."
Why did your question remind me of that?
Get ready for a similar question.
Probably going to be expensive.
Oh, the good news; It is extremely unlikely that the low voltage issue is in any way related to the white smoke.


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