Discuss Main 100A switch tripping in the UK Electrical Forum area at ElectriciansForums.net

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Visited a job today. Small shop. 'Lectrics are tripping out. Ok! Newly rewired due to the problem that still exists. New board 100A main switch. Not rcd. Board has 12 rcbos. Intermittent tripping. When it does trip it takes out main switch and ALL rcbos. Tncs system. Not widely experienced so have asked a number of people, nobody has heard of this happening. Any thoughts guys n gals? Appologies no photos as yet
 
You say tripping so are we to assume it is provides O/L protection, if so has it been clamped?

What is the shop, is it heavy on load?
 
Board is in a locked cupboard. Not clamped as yet. Didnt have 1 handy today. Small charity shop. Tbh nothing heavy loadwise. Usual stuff till p.c. Small kitchen. Intermittent tripping apparantly. Not always every rcbo but a good number and most times the main switch aswell
 
Board is in a locked cupboard. Not clamped as yet. Didnt have 1 handy today. Small charity shop. Tbh nothing heavy loadwise. Usual stuff till p.c. Small kitchen. Intermittent tripping apparantly. Not always every rcbo but a good number and most times the main switch aswell

What is the main switch if it is tripping?
Are there lots of inductive loads on these rcbo's ... lighting etc?
Check tightness of all main common cables and busbars, arcing joints can cause rcbo's/rcd's to trip absent of any earth leakage.
 
3 seperate rings across the rcbos. My concern was the lights. Quite a few fittings on main shop floor. Im not positive of what type. Plug n play type transformers. Halogen or possibly small hallide lamps? Everything at board has been checked for connections etc. Could leakage or indeed arcing be of enough amount to completely wipe out a whole board?
 
I presume that you mean the main 100 mA is tripping as well as the RCBO's? A 100A main switch can't trip!

Not enough info to go on from what you have said but the line "newly rewired due to the problem" is a bit scarey!
 
No murdoch not mA. The main switch on the board is rated 100A. This operates aswell as the rcbos. I agree i havnt given enough to go on. Will be going back so will get some snaps etc. Apparantly the rewire was down to the current problem. Obviously the problem was never solved.
 
So was the main switch an over-current device or an isolator? Daz
 
Why is the customer not contacting the electrician that did the rewire ?

Edit: answred above

Bet they have moved to Oz!!

As said above, if it is a main switch, then it can't/won't trip!! It must be an RCD main switch. The oldish MEM ones look simularish to a main switch. Not enough info.

Cheers

Jay
 
So whereabouts is this cupboard? As others have said, a 100A main switch won't 'trip', it has to be physically turned off by somebody.
If someone was turning everything off before, rewiring the place won't have made any difference.
 
I had a customer a cupla years back that swore blind the main switch on a 3036 board was 'tripping'.. Though I know they don't do that, I could not think of any possible reason why he would have lied about it. He didn't come across as being stupid, had nothing to hide, etc etc.

Only thing I could possibly think of is old contacts being worn and and any springs within being a bit lively. I still don't believe it though!
 
I had a customer a cupla years back that swore blind the main switch on a 3036 board was 'tripping'.. Though I know they don't do that, I could not think of any possible reason why he would have lied about it. He didn't come across as being stupid, had nothing to hide, etc etc.

Only thing I could possibly think of is old contacts being worn and and any springs within being a bit lively. I still don't believe it though!

Well.........what was it????
 

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