Merlin gerin masterpact problem
Merlin gerin masterpact problem
(OP)
Hi all,i have a problem with a merlin gerin masterpact 800amp m08 h1 circuit breaker.
over the weekend the breaker has been randomly tripping with little load on it,the tripping mechanism will indicate a fault and the breaker will discharge
the phases have around 45 amps on them when this happens as the plant it usually feeds is not in operation,the loads on it are heating and lighting circuits etc from local distribution boards
the breaker will reset ok after the trip and then may go on for another few hours before it happens again
ive had issues on these breakers(there are another 2 fitted elsewhere)in the past when weather is bad,a lightning flash has been enough to trip them
im not clued up on them but am sure they dont have ground fault monitoring presesnt,im also sure they were not set up correctly when installed roughly 4 years ago
ive tried to enclose a few photos to see if you can shed any light on the issue
let me know any further details you may need
Thanks
over the weekend the breaker has been randomly tripping with little load on it,the tripping mechanism will indicate a fault and the breaker will discharge
the phases have around 45 amps on them when this happens as the plant it usually feeds is not in operation,the loads on it are heating and lighting circuits etc from local distribution boards
the breaker will reset ok after the trip and then may go on for another few hours before it happens again
ive had issues on these breakers(there are another 2 fitted elsewhere)in the past when weather is bad,a lightning flash has been enough to trip them
im not clued up on them but am sure they dont have ground fault monitoring presesnt,im also sure they were not set up correctly when installed roughly 4 years ago
ive tried to enclose a few photos to see if you can shed any light on the issue
let me know any further details you may need
Thanks






RE: Merlin gerin masterpact problem
RE: Merlin gerin masterpact problem
RE: Merlin gerin masterpact problem
Of course the tripping unit might be knackered too. There's a test port on the front for a breaker test set to plug in, or you could hire in someone to do a more comprensive test than you can from the test port.
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If we learn from our mistakes I'm getting a great education!
RE: Merlin gerin masterpact problem
RE: Merlin gerin masterpact problem
To me the breaker's Instantaneous setting (I) appears to be set to lowest (most sensitive). Plus I am not sure how other setting fares when plotted on a TCC curve.
For starters set the INST Setting near to highest and then have a testing firm test the breaker and have a coordination review performed by a competent engineer. If this breaker is representative of other breakers in the facility, they would be having much more issues or potential issues.
RE: Merlin gerin masterpact problem
RE: Merlin gerin masterpact problem
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If we learn from our mistakes I'm getting a great education!
RE: Merlin gerin masterpact problem
They suggested an engineer visit to re programme the trip unit to sort out the issue,it seems to be quite a common problem
RE: Merlin gerin masterpact problem