Comments on this incoming supply and fuse boards?

[FatAlan]

Looking to install a bathroom extractor and isolator. Looking at the set up it looks like a TT system with old fuses and later additions protected by an RCD. Looking forward to doing some testing before I jump in. It’s an ex LA semi with an extension to the side. Have so far been unable to locate the rod.

 

[Richard Burns]

It is not looking good for installing accessories in a bathroom with a voltage operated Earth leakage circuit breaker, especially as it seems that bonding may be in place. That possible shower off to the left seems like it could do with some attention as well. Presumably the earth rod would be the one going downward, but you can never tell. I am sure the rod will be nicely enclosed in a suitable earth pit and clearly labelled!

Lots of luck.

 

[FatAlan]

It’s the classic set up under the stairs. Supply comes in overhead. The large 32A volex supplies the cooker. Extractor will be in loft area above shower with ceiling vent.
House belongs to good friends and old neighbours. I managed to get SSE out to change my TT to PME a couple of years back so may be worth looking at seeing if it can be done hear. TBH from what I’ve seen of the rest of the house the wiring is a real mish mash. They’re having a lot of decorating and refurb done and have told them that if they’re knocking walls down etc now is the time to look at a rewire.

 

[Richard Burns]

I would strongly recommend that they get at least modern RCD protection for the installation as a minimum, the VOELCBs are not reliable.
The supply is overhead? They have really gone round the houses with the supply cable then.
For your extractor installation it is possible that, with an inline fan in the loft, you could manage to not have to change anything at the board, but I hope the light switch is outside the bathroom and that you are doing the work this year not next year.
If they are having decorating and refurbishment done then this is an excellent time to bring the electrical installation up to modern standards and should be done first.
I would never have pegged the Volex for the cooker, I thought the main board was cooker, sockets, lights up, lights down, but where is the immersion! Second board for extension sockets, ring and radial perhaps and lights, then a shower added later.
However assumption is the bane of electrical work.

 

[FatAlan]

Was definitely looking at doing work without touching board. It’s actually a ground floor shower room with pull cord light switch on ceiling just inside door. I should be able to get a fan isolator switch on the wall outside. Good thing is that there is a hatch in the ceiling with the remains of a decommissioned shower pump which is in the perfect position for the inline extractor.

 

[The Ghost]

Asbestos! in the fuse carriers.

 

[Richard Burns]

All TT installations that have higher than TN level RA require an RCD for fault protection and all circuits in a room containing a bath or shower require a 30mA RCD as additional protection and from the 18th edition so do all domestic circuits supplying a light. You would need to address this current lack as part of your install.
If you are not touching the board then a 30mA RCD fused spur at the bathroom supply is probably the simplest option.

 

[FatAlan]

What protection does the Chilton Type D provide?

 

[Marvo]

What protection does the Chilton Type D provide?

Unreliable. Even if it does trip to a reasonable voltage on the MET (30-40v), which in itself isn't going to be easy to test, you still can't test the disconnect time. I'm not sure what your regs say but I'd personally suggest that voltage operated protective devices should be replaced on sight with an RCD.

 

[FatAlan]

Cheers Marvo. I’m really intrigued by the old kit and to be honest feel that while teaching to current standards is ok it doesn’t prepare you for the previous 40-50 years worth of equipment that is still out there.

 

[Marvo]

No probs, I didn't realise you hadn't come across them before. It's a predecessor to the RCD but where an RCD trips to current inbalance this device detects voltage.

Check this out for an explanation

 

[FatAlan]

Yes. Must dip in to some more of JW’s videos.