3 phase "mini CU" needed

[ProDave]

I know this must be available, I just can't think from where.

What I'm wanting to do is connect a 4 post car hoist in an old building that's recently just been used as a store, but was formerly a car repair garage.

The fuse box is ancient with rewireable fuses and the owner doesn't want to pay for the cost of a new 3 phase distribution board.

But there's a 3 phase supply from the old board terminating in an old MEM isolating switch.

so what I want is a 3 phase mini CU to connect from that to feed the car hoist.

Anyone know where I can buy one? or is it a case of make your own?

I can find switch fuses, but I want an MCB instead of fuses.

 

[steptoe]

one way Dave?

I think its going to be a case of a 6 [7 if you want a neutral] module enclosure and make your own,

remember to have it type tested and get the relevant certification done before you use it though.

 

[karlb]

I would also be interested in this as the smallest ones I have found are 4 way and are huge. I was possibly thinking of trying to a adapt a 6 module enclosure in some way

 

[Riggy]

As Steptoe says, 6/7(+) module enclosure 3/4 pole incoming switch and suitably rated 3 pole MCB.

The beauty of this method is that you can write your own manufacturers instructions, which you can then comply with!

I prefer metalclad, but that's maybe just me.

 

[alpha spark]

I've seen one the size of a cu it had a 3 pole main switch and about 4 ways the bus bars were staggered in a strange arrangement not sure how old it was and if they still make them

 

[Evans Electric]

I had the same situation at the printers , 3Ph supply in an old isolator . They wanted to move our small machines into there so I made one myself . A Merlin metalclad enclosure with a dinrail, clipped in some 3 pole breakers and looped them together with cable !!!OMG!!!! Call the Electric Police !!! After 5 years service we've now altered it all again .

I did of course pay out

 

[steptoe]

I had the same situation at the printers , 3Ph supply in an old isolator . They wanted to move our small machines into there so I made one myself . A Merlin metalclad enclosure with a dinrail, clipped in some 3 pole breakers and looped them together with cable !!!OMG!!!! Call the Electric Police !!! After 5 years service we've now altered it all again . I did of course pay out

 

[wozz]

Out of interest what's the problem with fuses?

 

[Evans Electric]

no worries Deke,do you need any more photoshopped approval certs done?

No M8 I've taken it out again now .

 

[sellers]

what about a 3phase switched fuse? unless manufactures instructions state mcb needed?

 

[kme]

You can get 2- and 3-phase "comb" busbar...the 2- pole is good for a board full of 2 pole RCBo`s

 

[apprentice87]

Hi All,

What is wrong with this, done it a few times...!!

Metal 2 way consumer unit from Denmans, [

 

[kme]

What is "wrong" is that the CU isn`t designed by the mfr for that purpose - so you have to have it type-tested before doing this..................................

 

[steptoe]

John, when you are throwing the main switches away can you throw them away in this direction please.?

 

[ProDave]

Some interesting points.

Reading the above, I think I'll go with just a 3 pole MCB in a metal enclosure. I'll mount this directly below the existing isolator, so that will still be there as a means of isolation in front of the MCB.

As to type approval, it's my understanding that's only needed if you are manufacturing and selling something. Most "one off" or prototype units are exempt from those requirements.

As to why I want to do this? it's nothing to do with manufacturers instructions but wanting to avoid modifying this very old installation. The existing isolator is fed from 3 30A rewireable fuses. I only need a 16A supply. So rather than open the can of worms involved with modifying the existing fuse box and circuit, I'll just follow it with a 16A MCB and leave the rest alone. Anyway it's far better to have to reset an MCB if something trips than delve into this hideous old rewireable fuse box.

I'll use a metal enclosure mainly so it can properly terminate the SWA feed to the hoist.

 

[Sharpend]

John, when you are throwing the main switches away can you throw them away in this direction please.?

Isn't that taking the collecting junk a bit far when you start collecting someone else's?

 

[apprentice87]

Hi KME,

Yes, i take on board what you are saying, but the thing is, you have a four module enclosure that IS type tested to be a CU.

So, you throw away the main switch and fit a TP mcb. There is not really much difference between this, and having the main switch and two SP mcb's. Still 230V to earth, ok it is 400V between poles of the mcb, but it [the mcb] is designed for this..

As it happens, the only reason i do this, is because they never have just the metal enclosure version in stock, only the CU one, which is EXACTLY the same thing, but with a switch in it, [oh and it costs more!!]

Presumably the "just an enclosure" version IS type tested to have an MCB in it, as otherwise it would not be much use [although you could use it as a bird box i suppose!!] so it is not like i am using unsuitable parts or accessories, although, technically, strictly speaking, you are of course 100% right!!

john..

 

[Steve3948]

All this "type testing" and mixing Mcb's, it's all garbage, I'll do it how I like providing it's safe, tests ok then that's it, send the Electrical Police after me if you want, which court do I go to because I used a MK Mcb in a Merlin board. :red card

 

[alpha spark]

We do the same when doin shop fits throw the main switch and fit contractors on the din rail

The nic eic bloke has seen it and never said ought

 

[Steve3948]

We do the same when doin shop fits throw the main switch and fit contractors on the din railThe nic eic bloke has seen it and never said ought

Them must be very very small "Contractors" then, are they Part P :slap