Sync check

[RonShap]

Is there a simple applications guide for a sync check relay configuration? A SWBD with two mains (open transition) doesn't seem complicated, but I can seem to explain the circuitry connections needed to a local panel builder. A diagram or picture is worth a thousand words.

 

[davidbeach]

Typically the relay manufacturers provide connection diagrams for their relays. Find the manual for the sync check relay you intend to use and use that diagram. That will be much better than any generic diagram.

 

[unclebob]

Why do you need to check for synchro if you're using an open transition? Both the two mains will be feeding the load? Please provide more info about your application.

 

[RonShap]

Unclebob,
Sorry, you are correct. I meant closed tranition. It will be with two manually operated breakers.
I checked with Basler and their BE1-25, but they don't have an applications guide that shows the two relays and the related sequence of operation (dead bus, live bus, etc).

 

[davidbeach]

Manually operated.... What do you mean by manual operation? If manual operation is the pressing of a button that then causes electrical operation of the breaker then you can do this. If manual operation is switching the breaker by hand then you can't control it with the relays. Each relay will supervise the electrical closing of one breaker. Wire the relay to VTs on each side of the breaker and the contact of the relay goes in the close circuit of the breaker. Live/Dead conditions are set by switches on the relay, if the conditions are met the contact closes allowing the breaker to close if all other close conditions are met.

 

[waross]

If your two mains are from the same system you don't need a sync check. However if you don't trust your local utility, by all means use it.
If your alternate main is from a non utility source you will need it
Closed transition does open a can of worms in regards to protection, co-ordination, arc flash studies, and available fault current.

Bill
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"Why not the best?"
Jimmy Carter