HeLp with 3 phase

[p11jor]

Hi guys just need some help with 3 phase.I have done some theory on it a while back but not alot.So I get the fact there are 3 phase's and a neutral The three phases are colour coded and go to three separate parts on the 3phase db,Is this correct?What next? For the final circuits?Cheers for any help!

 

[Hawk81]

The 3 phases are brown, black and grey and will go into a 3 pole isolator on the 3 phase board. Then if you have 3 phase circuits coming from the board you fit the correct size tripple pole mcb. Then take the 3 phases to your socket/ isolator/ motor ect. You can also take single phase supplys from the board.

 

[johnboy6083]

The thing to remember is to balance the load across all 3 phases. The total neutral current will be 0 amps if all phases are correctly balanced, ie like a induction motor. In reality you will rarely see a 100% balanced DB.All phases and neutral must be run through the same hole in any metallic containment or equipment, to stop eddy currents. With 3ph motors, if you want change the direction, you swap any 2 phases over.When testing, your PSCC should be measured between live and neutral and then multiplied by 1.732. Some say multiply by 2, but in some situations, this could cause quite a difference.I can't think of anything else at the mo, but I'm sure others wil help.

 

[philipb]

Also dont forget 3 phase is 415volts between phases and is very dangerous,take great care when working with it.

 

[Knobhead]

If you have singe phase supplies fed from the board don’t go mounting sockets for example on different phases in close proximity to each other. There’s something about in the regs.

 

[p11jor]

Thanks guys

 

[RWJ]

If you have singe phase supplies fed from the board don’t go mounting sockets for example on different phases in close proximity to each other. There’s something about in the regs.

Your meant to put a
<<<<< 400V Between >>>>>
Sticker on them..........

BUT... in a recent conversation with IQ he claims in the BGB they've removed the need for the 400v stickers

 

[Knobhead]

Flippin double post!!

Aahh I’m not the only one it’s happening to.

I still wouldn’t be happy with sockets in say an office with 415V between them.
OK we don’t know the situation this is going to be installed in, but it’s something to bear in mind.