Purpose of Synchronizing transfer on MEP-803a generator trailer

[rorub]

 

[rorub]

Neither of those small 5+10 Kw synchronizers allow you to parallel 2 machines, just synchronize the frequency then shift the load from one machine to the other. You can not have both machines on-line together.
The small machines are different than the larger ones which are designed to be paralleled together.
You can physically parallel 2 small machines using several different methods that folks have posted on-line, but most of these methods are not really good for the machine.
There is a video out there where someone uses the voltage regulator from machine to control both machines. This would probably be better than simply forcing both machines to fight each other due to slight differences in voltage and frequency, but I'm not electrically smart enough to know how well that would work either, long term.

That’s the answer I was looking for, thanks. I will pass on this device. It was for sale locally so it interested me.

 

[Ray70]

Yup, that's one of the videos I was talking about. It will physically work, but the machines will fight each other a bit due to slight differences in output voltage and frequency. No idea if long term operation will cause any damage to the regulators or any other components. There's another video somewhere on You tube possibly?? where the guy rewires the machines to share a common regulator. ( which is similar to how the larger gens operate when in parallel )
He claims that method is more accurate and safer for the machines.

 

[Guyfang]

Neither of those small 5+10 Kw synchronizers allow you to parallel 2 machines, just synchronize the frequency then shift the load from one machine to the other. You can not have both machines on-line together.
The small machines are different than the larger ones which are designed to be paralleled together.
You can physically parallel 2 small machines using several different methods that folks have posted on-line, but most of these methods are not really good for the machine.
There is a video out there where someone uses the voltage regulator from machine to control both machines. This would probably be better than simply forcing both machines to fight each other due to slight differences in voltage and frequency, but I'm not electrically smart enough to know how well that would work either, long term.

Indeed. The first sentence says it all. They synchronize, not parallel.

 

[Guyfang]

That's indeed a WAY to parallel two small sets. It works. But the problem is, on two sets built to do Parallel work, there is some more circuitry. That involves some relays that in a mini second, decide that the sets are for some reason going out of matched phase. The relays pop the main circuit breaker. Why is that so important?

"but the machines will fight each other a bit due to slight differences in output voltage and frequency." Ray has this right. But what happens when they get into a "fight" with each other? One gen set can then "Drive" the other sets main gen. This can often lead to you needing a new gen set.

Yes it works. Would I do? hell no. Another thing to keep in mind. In the event one set shuts off, and kicks the circuit breaker, the one can often think, its safe to fool with the set now turned off. Unless you have more breakes in the set up then what was shown, you will still have voltage at the load terminals on the set turned off. And few folks turn off the main CB when this happen. So you can potentially have voltage being back fed into the second/turned off gen set. Why am I saying this? Cause PFC Wiltfang, in 1974 reached into a set turned off, and got bit.

 

[Ray70]

Yet all the more reason not to do it.... reasons most of us would have never thought of!

 

[Guyfang]

And this I just rememberd. Should you close the second main load CB, when that light is ON, you melt the contacts on the CB. I was in a power room in Ft. Belvoir, Va in 1973. The engineer school. Twice a month, they transferred the entire Fort load, from city power, to the power plant on post, for test purposes and training the young soldiers. When they did that, the students were allowed to also move the load back and forth. We had this Greek guy............. His English was at best, bad. He understood, close the second breaker when the light was ON. Well, what a light show! All the breakers and relays were behind plexiglass. What a show!! The Greek spent all his free time replacing melted contacts, for the next two weeks