Westinghouse Seltronic MCCBs - Settings and Time-Current curves
Westinghouse Seltronic MCCBs - Settings and Time-Current curves
(OP)
I'm doing protecton grading in a 415V distribution system which includes old Westinghouse Seltronic NC molded case circuit-breakers. My websearch for Seltronic data was unsuccessful.
Can anyone supply LTD, STD, Inst protection setting ranges, tolerances, and time-current curves ?
Can anyone supply LTD, STD, Inst protection setting ranges, tolerances, and time-current curves ?






RE: Westinghouse Seltronic MCCBs - Settings and Time-Current curves
You can probably get the information from Cutler-Hammer (Eaton Electrical) - they still sell these.
RE: Westinghouse Seltronic MCCBs - Settings and Time-Current curves
A few time-current co-ordinates would define the curves.
Is EasyPower a software for system analysis including protective device co-ordination curves ?
RE: Westinghouse Seltronic MCCBs - Settings and Time-Current curves
SKM has that in their library. Contacting Eaton-Cutler Hammer is you best bet.
RE: Westinghouse Seltronic MCCBs - Settings and Time-Current curves
Long-time pickup is function of the rating plug. The long-time curve looks pretty much a typical thermal curve on a thermal-mag breaker.
Instantaneous (short-time) is adjustable from 4X to 8X with an override pickup that is a function of the rating plug size.
The maximum interrupting time for the instantaneous is about 0.033 seconds.
Hope that helps.
RE: Westinghouse Seltronic MCCBs - Settings and Time-Current curves
RE: Westinghouse Seltronic MCCBs - Settings and Time-Current curves
RE: Westinghouse Seltronic MCCBs - Settings and Time-Current curves