3 phase Power question

the gavel

Hi all

We have a 3 phase 32a socket in our workshop run over 4sq cable.

We want to set up a test unit that will be moved to trade shows.

Can we make off a 3 phase plug on a tail and connect the other end into a small fuse box,
We’re we will divide up into 3 single phase main fuses and out to Mcbs to control individual appliances.

Example
L1 appliance 5kw
L2 appliance 2kw
L3 sockets and lights approximately 1kw

Questions
Could this work?


Would a 4 Sq cable be able to handle this ?


Would there be an unbalanced load ?


Any info or recommendations would be greatly appreciated.

Thanks
The gavel

2011

A few points:
1) A 32A socket should not be wired in a 4 mm sq. cable.
2) Is never possible to perfectly balance different single phase loads across a 3 phase supply. This is why a neutral is required. You just balance as best you can (like your suggestion).
3) Cables should be sized to suit the load and length of cable run.
4) Protective devices such as MCBs should be selected so that they provide adequate protection to cabling.
5) A 3 phase 5 pin plug can be used to supply a temporary board however cables must be correctly sized.

the gavel

Hi 2011 , thanks for the response

I thought the cable was a bit small all right.

So if the cable was say 10mm or 16mm suppling the 3 phase red socket.

Could I make a 10sq cable off on red plug top and at the other end get a small fuse box and connect

L1 L2 L3 to 3 single phase main fuses with 32a fuse
And neutral to unprotected neutral bar

From there connect L1 and L2 into 2 x 32a RCBO and L3 to a 20a RCBO and a 10a mcb.
Linking all neutrals back to main bar

Would this work ?

Would there be a problem with the neutral?

Thanks again
The gavel

Tuco88

It might be very difficult to terminate anything larger than 6mm^2 into that 3phase plug i would think.

..at least a 32A 3 phase plug.^
You'll fit it in a 63A....don't worry I already got my coat.

brightspark

An important point to consider too is what power options are available at the trade shows.