How would you change this.

[MrPupsi]

How would you go about changing this unit over?

Old wylex board with Pyro mains tails. Earthed via Pyro, and all circuits via conduit.

Protrudes out the wall so I was thinking 1 of options, as I can’t see any other way round it.


Option 1
Batten on each side of the DB to the same level of the current one, crimp all cables and mount new unit over the old one.
Take a 16mm cpc from old board to new board.

Option 2
Angle grind the DB so it’s level with the wall and do same as above.

Option 3
Remove current DB completely and try to get another one in the same space, attempt to alter conduits and pyro to fit.
Don’t fancy bending pyro!

 

[pc1966]

Actually one blindingly obvious thing just after posting is the pryo cables might be a lot less than 16mm so common crimps won't be OK as they are not size-converting.

Might be a job for a couple of big DIN terminals?

 

[7029 dave]

The best option would be, giving that the client would have to forebear decor etc, carefully dig out the CU, keep all existing lock rings/lock nuts in case imperial sizing, obtain a cu with no knockout's, make up template and pre drill for conduit entries, refit existing lock rings/lock nuts hence no need for joints etc, like for like retermination.

 

[pc1966]

The best option would be, giving that the client would have to forebear decor etc, carefully dig out the CU

That would be ideal, but given there is conduit entering both top & bottom it might be difficult/impossible to remove the old CU, or indeed find one to fit the same conduit-conduit spacing that can be inserted again and conduit attached.

I see a whole lot of re-threading pain going down that route...

 

[7029 dave]

That would be ideal, but given there is conduit entering both top & bottom it might be difficult/impossible to remove the old CU, or indeed find one to fit the same conduit-conduit spacing that can be inserted again and conduit attached.

I see a whole lot of re-threading pain going down that route...

Yes difficult, without seeing the job it's hard to see a good solution.

 

[UNG]

Great idea if it fit. If it doesn’t what then?

Is it permissible to use different components from different manufacturers to build a board?

It's a Wylex 3036 board if a Wylex skeleton board fits in the enclosure your not mixing different manufacturers components

im surprised there isn’t something out there ready designed for this issue as it is not uncommon.

Don’t like doing Frankenstein jobs but in this instance I don’t see how it can be avoided, but in doing so are we breaking our regs.

Personally I would either do a full rewire or walk away. But I would let customer know there could be electricians out there who are willing to do a Frankenstein job.

im not criticising either option, just giving my take.

The problem is some of these sites were originally a bespoke solution for each developer, 60 years on and an adapted solution is the only way to replace them

Not sure why you term this type of job a Frankenstein job is it because there is no out of box solution

 

[7029 dave]

Whats made it a ball ache, using threaded conduit entry with lock ring and a female bush, that is rubbish I always use socket and male bush for this type of install.

 

[ipf]

Whats made it a ball ache, using threaded conduit entry with lock ring and a female bush, that is rubbish I always use socket and male bush for this type of install.

Done 50-60 years back........maybe they ran out of mb bushes or couplings. Just a couple of lads dropped off on the job, stuck in the middle of nowhere, no van, no phone..........and they don't know the code for smoke signals....give 'em a break for using their initiative. ?

 

[richy3333]

I don't think they are suggesting grinding down the replacement CU, I think it is to level the old metal to the wall and then mount a new external one over the top.

In that case the old CU is simple a large box and the only real issue would be safely and professionally extending the cables to reach in to the new CU. For most of the cables probably MF boxes would do if the fit in the remains of that old CU behind.

Not so sure about the pyro, but I would be inclined to use bare crimps and glue lines heat-shrink to extend the pyro's tails. At 60A and enclosed as it is you could use 16mm tri-rated for that, assuming proper crimps and ferrules to match.

But I might have missed something blindingly obvious here.

Sorry. I read it as cutting the back out of the new Cu to fit over the old one. My bad - as the youngsters say ???

 

[Deleted account]

Not sure why you term this type of job a Frankenstein job is it because there is no out of box solution

Frankenstein job is basically taking components from different sources that where not designed to go together and adding them together to or incorporating into an older product.

So yes, “no out of box solution” that’s about the reasoning behind it.

 

[telectrix]

rip out the innards. fit din rail, main switch and RCBOs . get a lid fabricated, (needn't be too fancy, any F**k ups will be covered in stickers anyway),

 

[MrPupsi]

I did contemplate that Telectrix but unsure how BS would take to my own line of DB production.

Its a small studio flat, the landlord isn’t going to pay for a full rewire, especially when it doesn’t need one.

Turning the original box into a junction box with proper crimps/no maintenance joints, and then mounting over would look quite decent in my opinion.
Regarding using a grinder, it would only be to bring the existing box level with the wall to get a neater finish.

I get the whole walk away from the job mind set as I’ve done it many times before, but I don’t think it applies here when a satisfactory result can be had without going full rewire.

 

[richy3333]

You'd probably find that the band saw would be better than a grinder as there won't be any sparks.

 

[Dave OCD]

Better to leave that protruding and batten round the edges in order to fix a flat piece of ply for the new CU. It would give you more wiring space in the old enclosure in behind too.

 

[freddo]

The difficult bit is that the existing is a surface fuse box that has been partly flushed in, If it was all surface or fully flushed in it would be much easier!

 

[ipf]

Better to leave that protruding and batten round the edges in order to fix a flat piece of ply for the new CU. It would give you more wiring space in the old enclosure in behind too.

Most simple method, by far.

It makes me think, though. What extra work has been done, points wise. The number of outlets needed, these days, compared with the 60's doesn't bear thinking about. Looks like one ring and a cooker. I could see at a couple of 4 way extension leads around. Probably OK if not in a kitchen, though.
Wonder what that 2.5 is from the 5amp.

 

[MrPupsi]

The 2.5 was supplying a switch and socket on one of the walls.
I'm guessing it was intended to be a 3pin lamp plug and it has a normal light switch, but somebody decided to swap it over with a normal plug or just installed a normal plug instead!

Tenant told me it kept blowing the fuse wire when he plugged the hoover in and he lost his lights as well ?

As said, its a small studio, 4 x single sockets in the main living/bedroom area, 13a oven, a washing machine/tumbledryer all in one unit, a 3kw immersion heater and a few other bits like an extractor fan etc.