Electrical Expansion For Factory

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cullynofc

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Hi,

The factory I work in is expanding to include some high usage machines.  I was given the following information and I was hoping someone could simplify these notes and perhaps provide a simple diagram to show the flow of electrics.

"There are currently 2 x 400A supplies coming into the building from 2 x main switches.

Supply A feeds one area and is currently feeding around 200A per phase.

Supply B feeds into the switch room and is drawing around 180A per phase.

With the expansion program we are looking to more than double capacity which will push the limit of supply to over 400A on supply B.

There is enough power on supply A to transfer across to supply B which will require approx. 100A @ 400V taking this to approx. 380A of use.

There is no way to transfer energy between the feeds in its current existing form that was inherited.

So this requires the 2 x feeds to be brought into one system from the main switch panel into the building separate to the factory panel board, which will be a new panel board.

I would suggest based on current and future expansion this new panel board be installed and increased to a 2000A rated capacity.

We only have 800A capacity at present, but with expected expansion, then this upgrade will provide the correct panel board."

Any help is appreciated.

Thanks.

 
in short you need a bloody big board to combine the 2 supplies then re-distribute as appropiate.

Sounds like you may not be the right person to do this work. We know nothing about you so hard to say, but if you aren't used to this sort of work it is worth staying away from , or commissioning someone like Canoeboy to aid you. Canoeboy works on this size of system all the time.

 
Depends somewhat on HOW the supply is derived....are there two direct 400a supplies, or one split into two, or an on-site transformer, or.........

Last one I did we had to have an 11kV sub installed outside, and that was JUST to feed a server room! Mind you it was a BIG FO server room. Probably all going to get decommissioned shortly....hopefully by me

 
in short you need a bloody big board to combine the 2 supplies then re-distribute as appropiate.

Sounds like you may not be the right person to do this work. We know nothing about you so hard to say, but if you aren't used to this sort of work it is worth staying away from , or commissioning someone like Canoeboy to aid you. Canoeboy works on this size of system all the time.
And a thoroughly decent chap he is too, just don't let him near your goats for gawds sake

 
Please tell me you are not planning to parallel up the two existing supplies. Please.

If it's a new building I would seriously consider getting a new third supply for the new building.

 
Errm, yes.... I do not think the DNO would be very impressed with people paralleling their network... For one thing, you have no idea how the current will be distributed [it would depend on the different supply impedances] and so you will blow cutout fuses and/or damage service cables, and what about neutral currents??? you have no idea how they will be split between the two feeds, and, as neutrals are unfused, it is all a recipe for disaster.

john...

 
Most DNO's have a brick wall strategy for supplies.

In that a brick wall must exist in full between two separate supplies.

If not then you have to talk to them.

WPD for sure say this.

You can have personnel doors between but not much more IIRC.

 
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