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Can a Pre-trip contact be added on a VFD?

The time from the energization of the trip circuit to the Main contact to part is about 1.5 cycles, but it can be extended to 2 cycles by using a special coil assembly. the device that sends the signal to the trip coil, can, at the same time send a signal to another ``device`` indicating that the main contact will be parting in 1.5 or 2.0 cycles depending on the type of trip coil.
If there is a good fault sensing system, it will take 2 cycle from the fault initiation/sensing [.5 cycle tripping delay plus 1.5 cycle opening time] to part the contacts, again that signal can be used as an early warning signal for the 2 cycle time before the contacts open.
I suggest that whoever is designing the system study the C37.010 4.7 Figure 2 and see if the breaker operation is acceptable as is, or they will need a special trip coil.

CTA-ID : 2031049
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