QA problems at ABB Sace?
QA problems at ABB Sace?
(OP)
I recently rejected a switchboard going through factory test because of problems with ABB's MCCBs. I'm curious if anyone else is aware of a manufacturing problem? I'm unable to disclose everything because this is a 'live' problem where we are having some fairly concerned discussions with the third-party switchboard builder. The MCCBs concerned were all fitted with a shunt trip unit and a couple of auxiliary switches at the factory. Symptoms noted included the following, although not all breakers exhibited all symptoms:
- sluggish response to shunt trip (5 or 6 cycles to clear)
- failure to trip
- noisy operation (audible 'buzz' from the shunt trip coil)
- noticeably tight mechanism
I suspect that there's a tolerance problem on one or more internal components which is why the tripping mechanism is tight, certainly needing more effort to operate than either the Siemens 3VF series or the Merlin Gerin NS series equivalents I had available for comparison.
Anyone seen anything similar?
- sluggish response to shunt trip (5 or 6 cycles to clear)
- failure to trip
- noisy operation (audible 'buzz' from the shunt trip coil)
- noticeably tight mechanism
I suspect that there's a tolerance problem on one or more internal components which is why the tripping mechanism is tight, certainly needing more effort to operate than either the Siemens 3VF series or the Merlin Gerin NS series equivalents I had available for comparison.
Anyone seen anything similar?
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If we learn from our mistakes I'm getting a great education!






RE: QA problems at ABB Sace?
Gunnar Englund
www.gke.org
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Half full - Half empty? I don't mind. It's what in it that counts.
RE: QA problems at ABB Sace?
RE: QA problems at ABB Sace?
RE: QA problems at ABB Sace?
RE: QA problems at ABB Sace?
RE: QA problems at ABB Sace?
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If we learn from our mistakes I'm getting a great education!
RE: QA problems at ABB Sace?
RE: QA problems at ABB Sace?
The shunt trip coil for the 160A frame appears to be marginally capable of tripping the standard 3-pole breaker, but if the breaker is a 4-pole device or the breaker has some auxiliaries fitted then the coil doesn't reliably have enough power to trip the breaker. Manufacturing tolerances appear to give enough variation in the tripping force required to operate any given breaker to the extent that some trip and some don't. ABB have supplied a modified tripping coil, although at present it is a prototype and hasn't hit mainstream production.
The 400A frame tripping problems appear to relate to alignment problems with the coil assembly, and ABB must have known about it before we found the problem because a modfied design was available very quickly. The later design has two locating screws, so is easily distinguishable from the earlier type.
My understanding is that the magnetic release and the internal tripping coil used by the electronic tripping unit are ok, and this affects the optional accessory tripping coil.
I don't want to say too much as this is a live problem and is ongoing, but I do hope that ABB will make some effort to identify where these tripping coils have been used and offer a replacement.
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If we learn from our mistakes I'm getting a great education!
RE: QA problems at ABB Sace?
He was a really tough guy. But that time, he was shaken. And me too.
Active tripping is something I never understood. Trip when anything fails is what I prefer. Active tripping - too much that can go wrong and not be noticed until needed.
Gunnar Englund
www.gke.org
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Half full - Half empty? I don't mind. It's what in it that counts.
RE: QA problems at ABB Sace?
I had a problem similar to yours when a 275kV breaker failed closed and we couldn't de-sync a generator. Having dropped the field it defiantly continued to run as an induction motor because of the tiny windage losses of the steam turbine under vacuum. We transferred the other machines to the reserve busbar and isolated the main bus section to get the generator off the system. I was very happy when that day ended with nothing broken and no one hurt.
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If we learn from our mistakes I'm getting a great education!
RE: QA problems at ABB Sace?