Discuss 3phase cut out for Isolation in the Commercial Electrical Advice area at ElectriciansForums.net

Electro-tech

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Hi Guys, Have a situation with a Wylex 60A single phase switch fuse isolator that is overheating & conductor insulation is burnt. It is supplied by 25mm tails from a henley block. There are also more henley block connections across all phases which I don't like at all. Anyway, for safe isolation, the only means is to pull the main fuses. The DNO's supply is a Lucy 185mm cut out. There are no seals in place, looks like previous workers have removed them if they were there in the first place, knurled nuts holding front cover on. I am thinking 70mm supply by the size of the main earth. To pull or not to pull the fuses? To prevent a fire, or would the DNO come out as an emergency? Either way, there will be a power down & I guess we would have to wait for someone to replace the fuses when the remedial works are completed. The company is a minibus service with garage workshops, for local County Council & have a tracking system & a lot of IT equipment, phones are important for parents if they need to check on their child. Meanwhile, the supply is only ticking over until the morning when the office staff come in, the total load previously measured was around 52 Amps. I would like to turn the 6oA supply off as being unsafe, but I guess it could have been like that for ages. Would appreciate some input & thanks in advance for your time.
 

Pete999

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Hi Guys, Have a situation with a Wylex 60A single phase switch fuse isolator that is overheating & conductor insulation is burnt. It is supplied by 25mm tails from a henley block. There are also more henley block connections across all phases which I don't like at all. Anyway, for safe isolation, the only means is to pull the main fuses. The DNO's supply is a Lucy 185mm cut out. There are no seals in place, looks like previous workers have removed them if they were there in the first place, knurled nuts holding front cover on. I am thinking 70mm supply by the size of the main earth. To pull or not to pull the fuses? To prevent a fire, or would the DNO come out as an emergency? Either way, there will be a power down & I guess we would have to wait for someone to replace the fuses when the remedial works are completed. The company is a minibus service with garage workshops, for local County Council & have a tracking system & a lot of IT equipment, phones are important for parents if they need to check on their child. Meanwhile, the supply is only ticking over until the morning when the office staff come in, the total load previously measured was around 52 Amps. I would like to turn the 6oA supply off as being unsafe, but I guess it could have been like that for ages. Would appreciate some input & thanks in advance for your time.
Does your "Safe Isolation Dilema" come from a single or 3 Phase installation, would maybe sugest a call to the DNO to install a TP and N isolator
 

buzzlightyear

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I would agree on that score with peter ,once one is fitted you can isolate the full system and change the fuse isolator .
 

Pete999

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I would agree on that score with peter ,once one is fitted you can isolate the full system and change the fuse isolator .
What's with the Peter Buzz? Pete will be sufficient:tongue: Never liked that Name anyway. Still better than the name my Mum wanted to call me before I was Christened!!!!!!!!!!!!!!!!!!!!!!
 

telectrix

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we are not a team because we work together, we are a team because the marketing suits think it makes us look good to the punters.
 

telectrix

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pretty much the same as the local nick cell block is now a "custody suite"

suite my arse, it's a cell block.
 
OP
E

Electro-tech

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Does your "Safe Isolation Dilema" come from a single or 3 Phase installation, would maybe sugest a call to the DNO to install a TP and N isolator
Thanks, Pete, it was in the title 3 Phase. I agree with you! Maybe the best approach would be to provide an Isolator & upgrade the supply so we can add a new DB & get rid of unnecessary Henley blocks across all phases. There are no means for further expansion at present. Anyway, hope the place does not burn down in the meantime. Cheers Guys.
 

anthonybragg

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The DNO usually only fit up to 100A 3 phase isolators for use with self-connection. After that, it is the customer to supply a switch-fuse/main switch with the "tails" going directly into the metering chamber.
Have you got only one load off each Henley block if not you would need to consider an MCCB panel board?
You need to find out the cause of the 60A switch fuse burning out.[/QUOTE]
 

Spoon

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What's with the Peter Buzz? Pete will be sufficient:tongue: Never liked that Name anyway.
We can call you "Stud Muffin" instead, if you like...
 

Pete999

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Don't know what Sparkjack will call you?
Yep Peet, but I don't give one, he is a non entity in my life, a mere blot on the Horizon that you come across in this short life span we have as Human beings, not worth a second thought.
 

Pete999

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Yep Peet, but I don't give one, he is a non entity in my life, a mere blot on the Horizon that you come across in this short life span we have as Human beings, not worth a second thought.
Am I bothered, does this face look bothered? do I give a Monkeys?
 

Pete999

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Anyone who can continually spill the vitriolic carp he dished out, and blaming it of Alcohol, deserve all he gets, bit like drink driving really. But enough don't get me started please.
 

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