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ATS short circuit rating

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kookypedia

Electrical
Jun 9, 2016
62
Guys,
I have an ATS data sheet and wondering what is 100KA? Is this the current that ATS can stand (not interrupt) for no more than 0.05 second?

Breaker_grr2w2.png


An investment in knowledge pays the best interest (Benjamin Franklin).
 
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This is a 3-cycle rated ATS per UL 1008. This unit is able to withstand a fault of 100 kA for 3-cycles (0.05 sec) and up to 42 kA for 18 cycles (0.3 sec)and not exceed certain damage criteria.
Should be noted that If circuit breaker is used, must have an instantaneous trip and clear as follow:
. ATS ≤ 400 A Continuous 1.5-cycles clearing time and tested for 10 kA.
. ATS > 400 A Continuous 3-cycles clearing time
When protected by current-limiting fuses, the ATS, regardless of manufacturer, amp size, and options used, have higher interrupting rating same as the fuse up to 200,000 A.

WARNINGS:
The ATS rated for 3 cycles (0.050 sec) are not suitable for mission critical or life safety systems such as heath care facilities where continuity of service is crucial. The NEC requires ATSs to be “listed for emergency system use”
Use circuit breakers with short time delay cannot be used for 3 cycle rated ATS.


 
The ATS is not intended to interrupt fault currents. It is intended to be protected by a breaker that meets the limits stated on the rating plate.
The withstand rating as opposed to the interrupting rating is given in a previous post.

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