Adjacent sockets on different phases

[briwire]

I have been asked to provide two 32 amp blue industrial type sockets in a server room by the IT fella at work. The loading could be around 25amp on each.

We have a 100amp DB nearby which is operating at around 50-60amp. I don't want to put both sockets on the same phase as it might exceed the 100amp DB feed. I would prefer to feed them from different phases.

I'm not too familiar with the 17th edition, but seem to remember the 16th saying that sockets fed from different phases have to be a minimum distance apart. Anyone know how the 17th treat this?

A solution could be not to use sockets, but a fixed connection to two adjacent isolators. Does the 17th allow this? I would have to clear it with the IT man first though.

 

[plugwash]

IIRC it's ok to have sockets on different phases close together as long as you put up a "danger 415V" warning notice.

 

[electronicsuk]

Wouldn't recommend it in a domestic environment, but somewhere more controlled like a data room is a little different. I wasn't aware of anything forbidding it in the 16th or 17th, but I wouldn't be happy stating that as fact.

 

[RF Lighting]

IIRC it's ok to have sockets on different phases close together as long as you put up a "danger 415V" warning notice.

Yep. Regulation 514.10.1 requires this. (second paragraph)

Although it would be 400V these days

 

[Stoday]

If you couldn't have two adjacent single phase sockets on different phases, you'd never be able to have a three phase socket.

 

[bernardgreen]

Even if the electrical regulations will permit the two sockets to be on different phases you need to confirm with the IT people that the equipment can be fed from two different phases.

In theory with modern individual power supply modules in IT equipment racks there should not be any serious problems in the racks if the supply modules are fed from different phases. But if the power supply modules are in any way linked or synchronised with each other then the use of two phases might present the IT people with problems.

 

[plugwash]

I really can't see it being a problem. Some servers have redundant PSUs but the whole point of those is if one PSU or mains supply dies the server keeps running so I would expect the two PSUs to be designed to be as independent as possible.

 

[ColJack]

can't see why not as long as the sockets are labled as which breaker feeds them..

the only concern I could see is that if the socets feed 2 things in one rack then the data cabling needs to be rated for 400v not just 240... but surely most of it would be anyway? ( usually 300v and 600V ratings?)

 

[electronicsuk]

I really can't see it being a problem. Some servers have redundant PSUs but the whole point of those is if one PSU or mains supply dies the server keeps running so I would expect the two PSUs to be designed to be as independent as possible.

Yes, they are totally isolated units in every server I've seen. They have to be in order for you to be able to pull out the broken one while leaving the other in place.

the only concern I could see is that if the socets feed 2 things in one rack then the data cabling needs to be rated for 400v not just 240... but surely most of it would be anyway? ( usually 300v and 600V ratings?)

I wouldn't think that's really necessary any more than with the phone/data/coax cables that are physically in contact with mains cables behind your TV. The patch and power leads within the rack aren't really part of the fixed installation, and the cables that are fixed will be routed well away from mains wiring in a datacentre to reduce the chances of interference.

 

[SteNova]

i've got this setup in my server rooms, everyone who has access to the rooms knows the setup, it's all marked up with 415v stickers

and they are a bit tidier than when i started working there