Need help with wire spec- Cold room

[bernardgreen]

Its 3 phase and N bernard so a bit more copper

Drat, I should be more carefull

2.5 mm £70.50
4.0 mm £100.00
difference £29.50

Even 5 core 4 mm would not be that much extra 3 phase Neutral and Earth

oops, container, big metal box, earthing might need a bit of good design. Safety devices to prevent accidental lock in of employee or boss.

 

[stillp]

The volt drop will increase the pull-in time of the contactors, possibly leading to an early failure of the starter (and the consequent loss of all that food). Much better to spent the extra few quid on 4mm².

 

[kavehh]

Thank you For all the information. I hope I can contribute to this forum somehow in future.

Went for 4mm 5 core. A bit expensive a my £150 but peace of mind.

Also putting a switch just before the freezer

Found this in box and I think it's quite dangerous how it's been done. Don't think the electrician is happy to work on the box like this

Almost touching the box

 

[333rocky333]

Hard to see what the wires do, your electrician may be able to sort that, at extra cost, providing he can get access to turn the power off, maybe just needs a large bush and locknut.
That is one reason you should NOT remove the cover with the power on, though if it is the incoming supply there maybe no simple way to turn it off.

 

[Iggifer]

Hard to see what the wires do, your electrician may be able to sort that, at extra cost, providing he can get access to turn the power off, maybe just needs a large bush and locknut.
That is one reason you should NOT remove the cover with the power on, though if it is the incoming supply there maybe no simple way to turn it off.

It will turn itself off when one or two of those phases rubs down to the copper! Will be a spectacular switch off I imagine depending on the size of the incomer.

 

[kavehh]

It will turn itself off when one or two of those phases rubs down to the copper! Will be a spectacular switch off I imagine depending on the size of the incomer.

It's 16mm 3 phase and the brown is the live wire. Told the neighbour but he seems quite relaxed about it. It already ate through half of the protector. It's matter of time before we have a firework there. I separated mine from that box. The MCB were old from federal electric and needed mcb on the day so went for a box.

 

[Iggifer]

It's 16mm 3 phase and the brown is the live wire. Told the neighbour but he seems quite relaxed about it. It already ate through half of the protector. It's matter of time before we have a firework there. I separated mine from that box. The MCB were old from federal electric and needed mcb on the day so went for a box.

All 3 of those are live. Brown is L1 but Black is L2 and grey is L3.

Those federal electric breakers basically don't open when they need to anymore.

I accidentally cut through a live cable on a 6A FE breaker and shorted to earth. Big Bang, went to check the board and the circuit was still energised. And that was only a 6A