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Phoenix

Operating aged switchgear problems

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Phoenix

Was thinking I can't be the only person to have had stuff like this happen, but have others had issues with older kit that perhaps hasn't been maintained as well as it should have.

 

Today's drama involved a 200A switchfuse unit in a pain panel in a mains room that I'm guessing that I guesing prior to the current roller shutter doors, may have had louvered doors due to the many spots of surface rust on it. You can see where this is going can't you. Switched off fine but when it came to switch back on, would not move fully into engagaed position, oh, and it wont latch into fully off position, and therefore the door is solidly locked. No amount of moving it back and forwards through the amount it will travel would result in it going fully to either state, nor would choice of four letter words, or banging it loudly. Go off and have a cup of tea, back and it still hasn't amazingly sorted itself. Damn. Trying to get the cover forward with an old large terminal driver opens up a slight gap and can see that the carriage is fully retracted, but the door is held on interlock for some reason. So with handle held in fully off position, with enough 'persausion' it opens. bit of oil on the interlock mechnism (which dosen't look so bad) and n the handle mechanism on the back of the door (which does seem quite rusty), as well as on one of the locking catches on one side of the carriage which wasn't closing properly. we finally get the thing to shut up and switch back on.

 

I hate touching stuff thats not been moved in 20 years or more!

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Sharpend
Just now, Phoenix said:

 

 

I hate touching stuff thats not been moved in 20 years or more!


perhaps this is the reason the missus doesn’t touch me???

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roys

The last one I had similar to that was an ACB bus tie breaker on a 660V board. Pressed trip with the remote key switches, failed to trip, stood to the side of it and pressed the manual trip, still no trip, oh oh. Got all the loads removed, then tripped the incomers.

Defeated the door interlock, then my mate and I set about it with our big screwdrivers being very aware of the spring mechanisms, eventually it tripped with a very load mechanical bang, both of us looked at each other wondering if each other still had all ten fingers.

Definentley one of my more check clenching moments.

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Tony S

What make of switchgear is this?

 

I’ve resorted to a scaffold pole on the handle and mindless violence. Shorting across a 4000A 660V ACB raised a few eyebrows but it meant I could demolish the ACB from the front.

 

One problem with old switchgear is the grease on the switch blades drying out and acting like glue.

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roys

Terasaki, if my memory serves me correctly.

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Tony S
5 minutes ago, roys said:

Terasaki, if my memory serves me correctly.

 

From memory that should have RoB swearing.

 

But it’s the switchgear the OP is working on I was asking about.

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Phoenix

It was an old Dorman Smith panel, installed circa 1974

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Tony S

Replacement parts are unavailable (discontinued 1997) so you’re going to have to be gentle.

 

Try putting a bit of tension on the rotary handle with an adjustable spanner and hitting the pivot point with a hammer, it should shock the switch open. Clean the switch blades and apply a small amount of Vaseline.

 

A word of warning, some old switch grease is carcinogenic, wear gloves.

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Evans Electric
On 25/01/2020 at 12:13, Tony S said:

some old switch grease is carcinogenic

Now he tells us . 

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Tony S
6 minutes ago, Evans Electric said:

Now he tells us . 

 

The green switch grease made by Castrol was withdrawn not long after I came out of my time. Everyone had a tube stashed in their tool cupboard, I was still finding them 30 years later.

 

I’m sorry but I thought most electricians knew about this. It’s why I recommended Vaseline.

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Evans Electric

No need to be sorry Tony , not your fault ,   just that I'd never heard of it being carsinogenic  .     Lets face it there was a load of stuff the same ,   soldering  was one , cutting MDF was that another ,    plasterers suddenly wearing face masks to mix when dry ,  asbestos gaskets around switch fuse doors  etc 

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