UL489 and IEC947-2

[StuMurr]

We are currently re-furbishing an offshore platform built to North American standards. Part of re-furb is to equip spare space on an existing 380V switchboard.

The switchgear uses Masterpact MP16H1 ACB's. My problem is that we are based in the UK and the circuit breakers in the original switchgear are obselete. I have been offerd a quote for the same breaker to but can only be made to IEC947-2, the orginal breakers are certified to UL 489 - question is what is the difference between the two? Does anyone have a comparison so I quantify the differnce?

Appreciate anything anyone can offer.

 

[dpc]

UL 489 is for molded-case circuit breakers. A UL 489 breaker has no withstand rating and must be equipped with an instantaneous trip element. I believe the IEC947-2 spec is similar, but the short circuit testing requirements are somewhat different. The UL breakers will have a fixed thermal trip setting (non-adjustable) but may have adjustable instantaneous trip.

Since most manufacturers such as Cutler-Hammer and GE build to both standards using the same frames, I doubt there is much difference in the internals of the breakers.

 

[rbulsara]

You may have better luck contacting either Square D compnay in the USA which is now owned by Schneider group. Sq D sells UL listed Masterpacts in the USA. Or you may conctact Merlin Gerin , the mfr, of masterpacts , in France, also owned by Schneider group.

I beleive if it physically fits and electrical characterisrtics are acceptable, you should be able to convince the owner or the authority to accept a breaker meeting IEC. The UL is a well accepted / code recognized standard, but not a Code requirement or a law requirement in the USA. In other words its not illegal to sell non-UL listed items in the USA, but you should inform the people concerned.

 

[dpc]

It probably doesn't apply in this situation, but actually it is not uncommon for equipment, especially circuit to be rejected if it does not have a UL label. This varies depending the local and state inspectors. In the Northwest, the inspectors are generally insistent on UL labeling.

I've learned that you can't always appeal to logic when dealing with inspectors.

 

[rbulsara]

dpc:

you last sentence is very true.. unfortunatley lately (in fact one curerntly) I have run into three of them...