Feeding 4 FCUs using 4mm 32A cable - how?

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Hello,

I've got a 32A breaker feeding 4mm (32A) T&E cable, which in turn is to feed 4 FCUs - that feed two 12.5A ovens, a 5A microwave and a 1A extractor fan.

That's two 13A fuses, a 5A and 1A fuse.

My question is, how do you get the 4mm cable to each of the FCUs?

You can't loop in an out because the cable entry hole in the FCU will only fit one 4mm cable.

I see from the post below, that the 4mm cable has to supply each FCU, and then it's permissible to use cable appropriate to the fuse rating in the FCU following the FCU.

//www.diynot.com/forums/viewtopic.php?t=113061

So I can't go from 4mm to smaller cables before the FCUs.

30A connector blocks are not big enough, same problem with 30A junction boxes - and they're under rated too.

25mm crimp to split the one cable four ways? Where do you get a crimper to do that? There must be an easier way.

Thanks.
 
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What brand of FCU are you using? Fitting 2x 4mmsq conductors into the terminals on a good quality accessory should not be particularly challenging.
 
You can't loop in an out because the cable entry hole in the FCU will only fit one 4mm cable.
Either the FCUs you have are junk, or the cable isn't 4mm.

Most of the FCUs I have used / seen have terminals similar to those on socket outlets, and you can get 2x4mm cables in there easily.
 
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So I can't go from 4mm to smaller cables before the FCUs.
You can have a short run (IIRC 3m) of cable just before the FCU rated for the fuse inside the FCU (so 2.5mm² to cover 13A) as long as it can take the prospective fault current. But then again...

... you shouldn't have to. As others have said 2 cables in there shouldn't be an issue.
 
Don't know where this fairy tale has come from.

If 'The Regs' allow us to feed an unfused 2.5mm spur off a 4mm radial, (providing it supplies one single/double socket outlet only) - then why on earth wouldn't you be allowed to feed a 13 A FCU in 2.5mm from a 4mm radial?
 
I can only assume you are using rubbish FCUs, and that they match something you already have.

I wouldn't consider 30 amp junction boxes undersized.

They are designed to accomodate 2x 4 mm cables.

So, to get three to fit, get a cable to run CONTINIOUS from the supply to the last FCU.
At each other FCU location, remove some cable sheath without cutting the wires.
Remove the terminal screws from the jb.
Line up the cable with the terminals of the jb, trim sheath back so cable fits neatly into cable entries.
Still do NOT cut the cable. Keep it continious. With a knife remove just enough insulation on the live and neutral so you can neatly 'drop' the cable into the terminals.
Now run a cable from the FCU to the junction box.
Connect the cable into the jb.

This way you effectively have three cables at the junction box, but only have to get two wires under each terminal.

You can only do this if the junction boxes are all accessible.

It would be more desirable not to fit joints, and fit different FCUs with larger terminals.

Use 35 mm or even 47 mm deep boxes to make wiring up easier.
 
I don't.

What's the point of all that fannying about, and all those unnecessary joints when all the OP needs to do is buy some decent FCUs?
 

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