QA problems at ABB Sace?

I do not know about SACE. But I have seen very problematic quality issues with other supposedly reputable manufacturers. I see it as a result of bean counters taking over all aspects of engineering and newbies doing all their work on simulators. I do not like it at all.

Gunnar Englund
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Half full - Half empty? I don't mind. It's what in it that counts.

I agree with Gunnar 100%, see the same thing. Not to be cliche but they don't make them like they used to.

Does anybody still make them like they used to?

Nope, no one will ever build another Magnablast, those things will last forever if you maintain them and that is not good for business. Imagine if GM made a car good for a million miles, they would sell a ton of them and be out of business in a few years.

SEL anyone?

I'll post an update about the MCCBs when I get chance to speak to ABB about this problem. Hopefully there will be a good explanation why we have a batch of bad breakers, although I'm having a little difficulty imagining what kind of explanation would be excusable.


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If we learn from our mistakes I'm getting a great education!

smallgreek - Are you using SEL as a modern-day example of Magnablast, or another company that has gone off the rails?

OK, a brief update:

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!

I certainly hope so, too. A non-functioning tripping coil is among the worst things that can happen. My old colleague Djurgardskalle once had to use a plank to trip a 10 kV breaker where the tripping coil failed.

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
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Half full - Half empty? I don't mind. It's what in it that counts.

De-energise to trip designs are rare on big systems because of the high holding power which would be required from the tripping battery, so instead there are duplicate or triplicate tripping systems on major transmission and generation substations. Distribution subs tend to fall prey to the cost / benefit equation and get a single tripping scheme, perhaps with a breaker fail scheme if you're lucky.

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!

After lubrication related failures trip coils have to be one of the most common failures.