I gotta question I never had before

[Pootnaigle]

I recently had occasion to PHASE 2 generators together. I have never done it before and after the readings I got on the voltmeter I aint entirley sure it can be done . seems to me if they are out of sync by just a tad yer Voltmeter will go nutz. So I spoze I am askin fer sum Technikal advice, ( wuz 480 delta ) Awaiting everyones input but Swamps.

[BigClive]

I recently had occasion to PHASE 2 generators together. I have never done it before and after the readings I got on the voltmeter I aint entirley sure it can be done . seems to me if they are out of sync by just a tad yer Voltmeter will go nutz. So I spoze I am askin fer sum Technikal advice, ( wuz 480 delta ) Awaiting everyones input but Swamps.

We covered that at college during my apprenticeship many moons ago. There were lamps connected between phases of the two generators and you could see when they were running close to sync by the way the light moved between the lamps. When the speeds were near enough matched we waited until the sync lamp went out and banged the switch in.

Never had to do it in real life though.

Here's a vid of a biggie being synced with a few extra bells and whistles.

http://www.jcmiras.net/jcm/item/98/

[tramp67]

If it's portable generators you are trying to sync, I wouldn't try it. There's a good chance you'll burn one or both up in the process. Large generators that have the controls to adjust frequency (rpm's), excitation voltage, vars, etc are designed to be run together. Your typical stand alone generator scenario will end up with one generator taking all the load, and possibly backfeeding to the other generator. trying to drive it as if it were a motor. Generator protection is also a fairly comlex control scheme to add after the fact.

[Figurehead]

Used to do it on ship in the Navy, gen to gen, ship to ship and ship to shore. Using the cabinet mounted synchroscope wait till 10 degrees before top dead center and slam in the breaker. Other than that have only read of using lights to sync and close the breaker. Did you get the generators to sync and the breaker to close? How?

[Pootnaigle]

Appreceiate your help guys. These were 2 300 kva 480 volt generators and while there are controls for the voltage and frequency there is no sync switch.
Also No lites available but I do see how the dark light method could work.
I bleve it would behoove me to find a different spot to hook em up where they wont ever tie thru the buss in the existing scenerio that needs to be fed temporary.
Needless to say this whole idea is the brainchild of an engineer...... the total load is about 100 amps and either generator should be large enough to carry that load........ But since the load is critical he doesnt want a generator failure to bring us down......... Thus the parallel generator scheme.

[BigClive]

You get generator systems where if one fails the other instantly takes over. It does require that they are both running continuously though.

They're used in the entertainment industry where loss of power takes the whole show down.

[shaun]

Used to do it on ship in the Navy, gen to gen, ship to ship and ship to shore. Using the cabinet mounted synchroscope wait till 10 degrees before top dead center and slam in the breaker. Other than that have only read of using lights to sync and close the breaker. Did you get the generators to sync and the breaker to close? How?

Me too. Always used the light to sync gens together or shift to shore power. You could speed up or slow the gen down to match the parallel and close into it. If or rather when ever you got it wrong it would rock the generator sumthin fierce. Poor ole BT's and MM's scattered! I'd like to know how it worked out too Fig, good question.

[tramp67]

You get generator systems where if one fails the other instantly takes over. It does require that they are both running continuously though.

They're used in the entertainment industry where loss of power takes the whole show down.

Like a mechanical or static automatic transfer switch, right, Clive? For this scenario, I'd have to agree with you. Definitely wouldn't tie both generators together like the "engineer" wants to do. Then, if one fails, it might take the whole system down anyway. It doesn't sound like a very large system with much protection.

[Stinger]

I remember when I was in the CB's at a generator course, if I remmeber right we would use the sync lights, I did not bring the generator off the pad, so I guess I did it right. But that was back in the 70's. The generators I am talking about were 3 phase for supplying 120/240 for a forward base or encampment. Back then most of the 3 phase was 240V vs 120/208 like today.