Minimum Contactor Closing Time for Generator Synchronization

[bedane]

Dear all

I have a 1600 ampere electrical contactor which I plan to use for automatic generator synchronization using datakom automatic synchronizing module. The manual says the closing time of the contactors is between 40ms-80ms. But I have read on some synchronizing manual it says the closing time of a contactor should not be greater 20 ms. Can't I use the contactors. Please give me some advice.

Best regards

 

[waross]

The time window for a smooth sync closing depends on the difference in frequencies of the incoming set and the bus. The smaller the frequency difference the more time is available for breaker closing.
A statement that breaker closing must be less than 20 ms would be accurate only in reference to a specific combination of generator and synchronizing device.

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

 

[GTstartup]

Most modern synchronizers allow you to imput the closing time so the order to the breaker will be issued in advance. Check your manual.

 

[dpc]

As mentioned, you should be able to set the closing time in the synchronizing relay. Also, if you keep the delta freq low, the closing time has less significance.

The manual you were reading may have been for a device that assumed circuit breakers were being used and had an upper limit for the delay of 20ms.

I'd set it as close as you can and probably not worry about it beyond that. This is generally not critical.

 

[bedane]

thank you all
i also believe too that if the frequency is closely matched that will not be a problem. consider it with the manual synchroscope if the frequencies match good enough then the rotation of the needle on the synchroscope will be slow then when the automatic synchronize r tries to close at zero phase angle (12 o'clock position)the needle will not got far from the the zero degree position.that means not much greater phase angle difference.
BUT I have read that there are some automatic synchronization controllers which have a setting for advance breaker closing time setting which allows to compensate the breaker closing time.
please suggest me if you know one for the future use.
best regards

 

[GTstartup]

ABB Synchrotact 4/5 - expensive - complicated
Beckwith - Easy and not expensive

 

[jhonsom]

I see the SEL 700G relay has upto 1000ms and compensates for breaker close time.