Generator Problem

It could be possible due to leakage current like any electrical equipment could get ground that may cause leakage current to ground. I hv found this problem 2 times in my company.

First I assume this is a 3 phase gen. What is the voltage? What should the amperage be? Did you measure the actual amperage with a meter to see what it is? Let us know?

Is this generator run on line with other MG's?

If the amps are high at low KW when run alone you might have a problem with the exciter, check the diodes and the coils, be sure to use a megger on the coils and disconnect the diodes to check them.

Now if you are getting these high amps when it's on line with another generator it's the voltage regulator causing cross currents between the generators.

Dear,

The Gen set it self has not current means (load). When you put the load the current start to flow. It means that there is no fault in the Gen set there is some thing wrong on the load side.

I think you should check the load side may be cable insulation is weak or there is short circuit in the equipment you are using. In this case most probably insulation will be weak the cable you are using.

M.nasir Khan, welcome to CR4. Your reply brings up a good question and should not have been rated as off topic (OT). If this gen set does not trip with no load on it, then it very well could be a fault with the load or cabling to the load.

He rated himself off topic and someone (you?) has kindly taken one off. It was probably due to the bad grammar, but I agree, he was probably correct in what he said.

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The OP to ask such a question obviously has no idea what causes current flow/load on his generator. Its a constant mystery to me as to how such uneducated people come here and are asking such basic electrical questions......no wonder shit happens so often.

He is probably related to the owner/boss and got himself taken on for that reason......he should go onto the website of the Darwin awards, and imagine himself starring on page 1 one day:-

http://darwinawards.com/darwin/darwin2008-27.html

The current is too high causing the generator set acb to trip....

That is what circuit breakers are supposed to do.

....trip with only a small kw load.

If the current is too high then the load is not small.

What is the indicated or measured current on each phase? Voltages...? Frequency?

pl check the pf. If it is poor, then check if there is a problem with the load e.g. application of higher voltage than rated e.g use 380 V old motor on 440 V generator output . Pl check the voltage also as other possibility is over-excitation due to some fault in AVR circuit . Old AVRs ( E & I type) without electronic circuits used to have wider voltage bands and used to generate high voltage on low loads of the air gap was not set properly in them

I have to ponder why someone working with a "small" 250kW generator isn't aware of the process for working out why the trip is blowing?

Using the word "small" implies experience with bigger generators. The question, however, implies a serious lack of experience with anything electrical.

(Unless tech has jumped forwards a long way recently, a 250kW generator is at least the size of a small car, far heavier, and so not "small".)

If it is on load alone and all the rest is normal, a low load and high current could mean

1) a very low pf. Pls confirm your pf correction board is ok on all three phases.

2) If newly commissioned verify your ct ratings.

3)Confirm if your KW gauge is reading correctly meaning it is actually high load with high current.

Has the downstream wiring been tested and have all faults been eliminated?

hello delta , pls tell us the small kw load your consuming ???

and the tripping that you mention is there is a two posible problem !

1) tripping the ACB is more than the load than the genset spec load !!

2) may posible you have leaking current !!

3) pls tunr off all circuit breaker then start your genset and tunr on one by one of your circuit breaker this is to trace were is the line wire current leaking !!

hope this will give you an idea how to fix !!!