Split Suppy Advice Please

[Gazthesparky]

Can you post a picture of the consumer unit as stated it carnt take out a 100amp switch

 

[Marvo]

Can you upload some photos to Imageshack or Photobucket of the existing CU from various angles?

 

[Yorkie]

Don't under stand how it can take out the 100 amp switch as this is not a breaker unless it is an RCD ?

Dunno. But sometime it does if we get a really, really bright flash when a bub goes. I thought the 100A was some sort of rating, can they get a bit weedy with age?

 

[Wiresandthings]

Id say the bright flash when the lamp goes is even more of a worry than a lamp supposedly taking out a 100a breaker!! It must be a 100a rated rcd as main switch as 100A main switches don't trip

 

[Marvo]

Switches don't trip when there's a fault they're purely a device for manually isolating the supply. MCB's and RCBO's trip to a fault. I assumed your switch is an MCB (circuit breaker) when you said it tripped.

 

[Yorkie]

Thanks for the replies so far. My son-in-law is a sparky (but industrial, not Part P registered) so I'll get him to pull the lid off tomorrow and I'll take some photos.

Thinking back, when the CU was fitted the brand new 100A breaker was duff, wouldn't latch, and he had to fix something up for a day or two until he got a replacement (hence the reason for me getting goosed and over charged for labour). Maybe the replacement wasn't too smart either? I'll think about having it swapped while we're at it, just to be sure.

The consensus seems to be that if the switch is okay, just get the new CU fed from an RCD in the main CU. If so, what size should I ask for, is 50A big enough?

 

[Marvo]

I think photos would go a long way in getting better advice. Surely if your sons a sparky you could persuade him to install an RCBO for your garage circuit and take it off the RCD. Threaten to torture him with some childhood photos....it always worked for me when my parents did.

 

[Yorkie]

Update............... I'm glad I'm not doing the job myself.... .. 'cos I'm a berk.

Of course the new CU will take 25mm tails - they go into the RCD, not in the neutral rail. Agghh!. So all's well.

But of course, if all is well in the main CU, is it best practice to split the tails and feed each CU separately, or just to take it out of the main CU on a big ol' RCD (not under cover of the RCD that's in there)?

I don't mind spending a few quid extra so long as it's as good as it gets.

 

[Yorkie]

I think photos would go a long way in getting better advice. Surely if your sons a sparky you could persuade him to install an RCBO for your garage circuit and take it off the RCD. Threaten to torture him with some childhood photos....it always worked for me when my parents did.

Always an option, but I thought is was notifable work and he can't Part P register it?

I keep threatening to sponsor him to get accreditation, but the problem is that business is so good there's never any time. In any case, if the cables aren't as thick as your finger he's not always too interested!