I actually posted the data sheet link in this thread, not clear, but no mention is made of the oc element
The op said the are sc/instant only, no toc element
mag only is not uncommon on motor applications
or fire pumps
in mining they are the standard and are usually supplemented by an external OL pack
never heard a fa panel referred to as a 'booster' panel (btw, that word is not used in the panel schedules)
been to the following schools: Ansul, Fenwal, Kidde, Pyrotonics, Edwards, Honeywell, etc.
Worked for a firm for 4 years that did a large amount of work with fire/explosion suppression/detection (along with power dist) in the oil fields of Alaska, military facilities, telecomm facilities and Boeing facilities in WA: Seatronics Protection Systems
no motor loads anywhere on the system? or only downstream of the subject cb's?
as many have said:
turn the breakers up to a more reasonable setting, will not harm a thing since they have oc protection and will still be at a reasonable level (plus it doesn't cost anything but some time)
who knows what transients/reflections are being generated, on the line or load side
it sounds like the following has been eliminated:
cables are sound
no loads that would cause transients in excess of 300% of the rating
no correlation to generator transfer
no oc since loads are << than the setting and hold for days (or longer)
turning 2 breakers up at a time may isolate the offending circuit
what else is left?
Did you look at page 6-91?
The letter T, in position #8, indicates the breaker has Long time (e.g. thermal) tripping. There would be a letter I here, if this was a Motor Circuit Protector frame for magnetic only protection.
Just because you can, doesn't mean you should.