Upgrading garage supply

[galooph]

Currently (no pun intended!) the feed to my garage is a 6mm cable from the house consumer unit to another consumer unit in the garage. That's been fine for years, supplying a 32A ring for 13A sockets, plus a few other 16A sockets.

After reorganising the garage layout, the consumer unit needs to move, but I'm also going to need a 32A socket for a new compressor. I'm planning on taking a separate feed from the meter box over say 20m of 16mm SWA, run externally, clipped to the wall, into the garage. While I'm doing that, I might as well replace the garage CU, and use RCBOs in there. I followed @RaceDiagnostics thread with interest, as that's pretty much what I want to do.

There's not a huge amount of space in the meter box to play with:

It'll be easiest to bring the SWA into the top, into a fused isolator. What would the resident sparkys recommend for splitting the output from the switched isolator? Henley blocks, or is there an isolator that can take two pairs of tails on the output?

 

[brightspark]

your not going to get a metal 60 amp switchfuse with armoured cable in to that box with henley blocks the only 60 amp metal switchfuses that are capable of taking 2 sets of tails supply are the wylex or simlar and there big https://www.ebay.co.uk/itm/18743504...4QoszOrGhihsId0AAAAAA&loc_physical_ms=9219481 have you got room to put the switchfuse somewhere else within 3 meters length of the meter

 

[Memmeddu]

Currently (no pun intended!) the feed to my garage is a 6mm cable from the house consumer unit to another consumer unit in the garage. That's been fine for years, supplying a 32A ring for 13A sockets, plus a few other 16A sockets.

After reorganising the garage layout, the consumer unit needs to move, but I'm also going to need a 32A socket for a new compressor. I'm planning on taking a separate feed from the meter box over say 20m of 16mm SWA, run externally, clipped to the wall, into the garage. While I'm doing that, I might as well replace the garage CU, and use RCBOs in there. I followed @RaceDiagnostics thread with interest, as that's pretty much what I want to do.

There's not a huge amount of space in the meter box to play with:

View attachment 511650

It'll be easiest to bring the SWA into the top, into a fused isolator. What would the resident sparkys recommend for splitting the output from the switched isolator? Henley blocks, or is there an isolator that can take two pairs of tails on the output?

I'm honestly unprepared for that, we use totally different solutions over here.
But judging by the look of those wires Wich are 35mm² most likely.
I'd put a three phase breaker cause they usually have a double clamp we might say? Anyways slimmer port meant to have flat conductors fittings in them, an regular ports for stranded conductors.
Put bridge plates on the input side so you'll make it essentially have the red and black wires in the middle and the bridges connecting the 1st to 2nd and the 3rd to 4th input terminals
Then you would have an output on the 1st and 3rd, another to 2nd and 4th .
I can't see a better solution with the space you have and assuming that the grey wires can't be elongated without joints.

 

[Kayos]

I'm honestly unprepared for that, we use totally different solutions over here.
But judging by the look of those wires Wich are 35mm² most likely.
I'd put a three phase breaker cause they usually have a double clamp we might say? Anyways slimmer port meant to have flat conductors fittings in them, an regular ports for stranded conductors.
Put bridge plates on the input side so you'll make it essentially have the red and black wires in the middle and the bridges connecting the 1st to 2nd and the 3rd to 4th input terminals
Then you would have an output on the 1st and 3rd, another to 2nd and 4th .
I can't see a better solution with the space you have and assuming that the grey wires can't be elongated without joints.

They look like single insulated 25mm tails to me, never seen domestic 35mm as the meters are not designed for it

 

[Memmeddu]

They look like single insulated 25mm tails to me, never seen domestic 35mm as the meters are not designed for it

Surely bigger than most shops power supplies over here too.
We've way lower output power supply.
Regular household meters are just 3kW, someone has 6kW.
And most shops have just 10kW three-phase, we have 16kW at my workplace despite it's a big shop for our standards.
We have 5 lathes, 4 milling machines, a CNC milling machine, a Jib borer, a line boring machine, an cylinder head skimmer, a crankshafts grinder, a cylinder boring machine, a cylinder honing machine, a serdi, and the air compressor.
Those are never running all together but adding a couple of welding machines running.
We are underpowered we have an undersized electrical installation but somehow we are working every day on a 16mm² line

 

[galooph]

your not going to get a metal 60 amp switchfuse with armoured cable in to that box with henley blocks the only 60 amp metal switchfuses that are capable of taking 2 sets of tails supply are the wylex or simlar and there big https://www.ebay.co.uk/itm/18743504...4QoszOrGhihsId0AAAAAA&loc_physical_ms=9219481 have you got room to put the switchfuse somewhere else within 3 meters length of the meter

I thought it was looking tight! The house CU is just on the other side of the wall, behind the meter box (well within 3m), so that would be a good solution. Would you recommend doing the split inside the meter box with henley blocks, or daisy chaining the tails first to one of those Wylex switchfuses, then to the house CU?

 

[brightspark]

I thought it was looking tight! The house CU is just on the other side of the wall, behind the meter box (well within 3m), so that would be a good solution. Would you recommend doing the split inside the meter box with henley blocks, or daisy chaining the tails first to one of those Wylex switchfuses, then to the house CU?

id fit henley blocks in the meter box and fit one of these or simlar. there cheaper and only able to take one set of tails https://www.amazon.co.uk/100A-SP-Me...hvtargid=pla-2281435176698&psc=1&gad_source=1

 

[brightspark]

if fitting the double pole block id put it to the right of the meter pull the tails from meter out of the mem isolator and feed them up in to the block then drop a pair of tails from henley down in to the mem isolator that feeds the house then run the new tails out from henley block in to your new garage swtichfuse https://www.screwfix.com/p/greenbro...ikpAuurrkoXtaSVxXEVzRGuBwzI9CWSxoCRj0QAvD_BwE

 

[galooph]

Thanks, @brightspark - much appreciated!

 

[MetalMonkey]

You can tell octopus haven't been in there.
I wouldn't bring in anything through the top, you are just asking for a leak.

Are you intending on doing this yourself or getting somebody in?
Reason being if you are going to pull the meter tails out of the isolator you will need to pull the fuse or have it pulled, and probably want to check the terminals after moving them around too.

Another option would be to leave the current isolator as is, which would mean you have the ability to switch everything off and remove the feed to the CU out of the bottom and rejig things at your leisure.
Either by replacing the tails from the house CU to the meter box to allow you to fit henleys further up, or splitting the tails inside the house to give you the space to mount a suitable isolator to feed your swa.

Wylex do quite a compact 4 pole isolator in a plastic enclosure, REC4 but I don't think that's going to help you in this situation as you'd still need extra pace to terminate the swa into something appropriate.

 

[galooph]

You can tell octopus haven't been in there.
I wouldn't bring in anything through the top, you are just asking for a leak.

The box is recessed into the wall, but good point.

Another option would be to leave the current isolator as is, which would mean you have the ability to switch everything off and remove the feed to the CU out of the bottom and rejig things at your leisure.
Either by replacing the tails from the house CU to the meter box to allow you to fit henleys further up, or splitting the tails inside the house to give you the space to mount a suitable isolator to feed your swa.

This is looking like the preferred option, I think. Could be a good opportunity to replace the house CU at the same time, as that must be 30+ years old.