3 phase circuit

[boberty]

I am wiring for 3 32amp 3phase sockets, is it acceptable for all 3 to be wired on a radial? The equipment they will be feeding is often moved around, so cant say for certain what the total load will be. Any help greatfully recieved.

 

[telectrix]

i would deffo. not put 3 on 1 radial. individual circuit for each one.

 

[bugsy]

I'll second that - what is it with more that one outlet on 3 phase radials and even worse rings at the mo!

 

[boberty]

Thanks for replys will have word with client as dbs will be full once ive wired for first outlet.

 

[Des 56]

Perhaps feed a smaller dist board with the available way, and seperate ways from that dist board for individual supplies

 

[Engineer54]

I'll second that - what is it with more that one outlet on 3 phase radials and even worse rings at the mo!

3 phase outlets or 1 phase outlets, all have to be designed and installed as to be fit for purpose...

So why is it a problem for you to have more than one outlet on a 3 phase radial?? Is there something different about the basic rules for 3 phase outlets to single phase ones??

Design the overall circuit right for the application and usage it is intended for, and there shouldn't be a problem!!! I'm not saying that every 3 phase outlet radial can support multiple outlets, that very much depends on it's application....

 

[Steve1412]

3 phase outlets or 1 phase outlets, all have to be designed and installed as to be fit for purpose...

So why is it a problem for you to have more than one outlet on a 3 phase radial?? Is there something different about the basic rules for 3 phase outlets to single phase ones??

Design the overall circuit right for the application and usage it is intended for, and there shouldn't be a problem!!! I'm not saying that every 3 phase outlet radial can support multiple outlets, that very much depends on it's application....

Fully agree. I have come across this many times. Very rare all the sockets would be used at the same time and circuit is designed for this!!!! Similar to busbar trunking with tap off units!!!

 

[bugsy]

Bus bar tap off's are fused, ( except lighting ), and what would the consequences be if a machine takes out the ocpd and someone else is using a woodworking machine or something simular, I just think it's bad practice ok for small workshop with 1 op in it but apart from that I think it's pants unless every point has its own fused isolator

 

[Engineer54]

As i stated before, you design and install a circuit to it's needs and requirements. If the designer see's a need for a switch fuse at the machine, then one shall be installed. You can't go round saying you ''can't'' have multiple outlets on 3 Phase radials or 3 phase rings based on your own ''What ifs and maybes'' !!!

Can you imagine the cost to wire every single 3 phase outet back to a DB in an industrial setting in the real world?? And that is why in 9 out of 10 cases they won't do it, and quite rightly so too!!!

 

[Knobhead]

In an ideal world you would run 3 separate radials from a new board. Unfortunately this isn’t that Nirvana, economics rears it ugly head every time.
As others have said you have got to go with what is practical.
There is one alternative and that is to fit fused socket outlets with a hefty radial cable.

 

[malcolmsanford]

I'll second that - what is it with more that one outlet on 3 phase radials and even worse rings at the mo!

Simple, it takes very little design concept to say 3 phase sockets, ok every socket on a dedicated radial, and that is becasue we are not training electricians as we should be.

Every installation should be designed on it's own merit, if individual radials is the best design then that is what it should be, if it is best to run a ring main and then take sockets off that ring, then that is the best design. The trouble is that to design a ring takes a little bit of thought, which some don't seem to want to do.

 

[Chr!s]

I would of thought a simple distribution circuit feeding protective devices for each outlet, that way you will have discrimination between the oultlets and the dB circuit.

 

[Steve1412]

Bus bar tap off's are fused, ( except lighting ), and what would the consequences be if a machine takes out the ocpd and someone else is using a woodworking machine or something simular, I just think it's bad practice ok for small workshop with 1 op in it but apart from that I think it's pants unless every point has its own fused isolator

Would expect machinery to be fixed equipment and as such on its own circuit. We are talking sockets which would be used for portable/movable plant etc.

 

[boberty]

Many thanks for all your reply's. The banging together of all the gray matter has been a great help. So when I got to the job this morning client had changed their minds, as is their option I suppose. Probably didnt want to spend more than they had to is more likely. So thank you all again till next time.