The Right Swa Cable For Machines.

[MARIOW]

Hello gentlemen. I'm fairly new to this but done some good quality simple jobs already as a sparky. I have a task to do and need to know how to select elements to make it right and safe. I've been asked to put 2x 16A sockets on the wall for 2 machines. One socket is already there and powered  by 1.5mm2 SWA cable (which can takes about 23A) and protected by 16A fuses (I hope this is right). Just been ask to put another socket (16A 3ph) next to that one (16A 3ph)for another machine. My query is: can I connect second socket to the same SWA cable and still make it safe and possible to run 2 machines at the same time? If 2 machines need 16 A each,cable rating is 23A,fuses are16A.

Thank You for any help.

 

[Essex1]

Welcome,

Am I right in saying you want to run 2 x 16A machines on a single 16A circuit?

 

[steptoe]

so,

you have a 1.5mm swa running to a 16a1ph skt and you now want to tag a 16a3ph skt onto it? 

Im confused as to how you would propose this could ever work?  :shakehead

 

[MARIOW]

I'm asking because I heard from another sparky that machines do not need full required current for them to run. And this confused me a bit. From my point of view (but I'm new to this) all the elements (cable,fuses) can't deliver requied current. But I thought he may be right. Maybe them machines will need 16A in "pick times"/ occasionally. In this case it could work.  BUt as I said I'm beginner and still learn.

It's 1.5mm2 SWA running to 16A 3ph socket

It's 1.5mm2 SWA running to 16A3ph socket,and I need to put another same socket next it.

 

[Andy™]

you can put as many sockets on the same circuit as you want, providing all wiring is compliant. but if you have a few machines that will always run near the max laod of the circuit, then you will get problems with tripping every so often

 

[steptoe]

ah, ok,

so both 3ph,

I'd still say no,

the first has more than likely been designed as a 16a radial feeding that ONE socket,

I cant see how you could justify adding another socket to it,

 

[Essex1]

You need to know what the machines will pull to then decide what you need to supply them with.

 

[steptoe]

you can put as many sockets on the same circuit as you want, providing all wiring is compliant. but if you have a few machines that will always run near the max laod of the circuit, then you will get problems with tripping every so often

thats easy,

you just put a bigger mcb/fuse in,  :C

 

[MARIOW]

So what is the best solution? Run another 1.5mm2 SWA cable for second 16A 3ph socket and make it separate circuit?

 

[Essex1]

If you need two 16A supplies then yes.

 

[MARIOW]

All I've been told is that I need to put another 16A 3ph socket next to one that is already there (16A3ph). 

 

[Essex1]

Ok. So what is the issue?

 

[bluetobits]

So what is the best solution? Run another 1.5mm2 SWA cable for second 16A 3ph socket and make it separate circuit?

You need to know what the machines will pull to then decide what you need to supply them with.

As Essex says, you need to determine the load characteristics of the machines in question and then make a decision as to whether an addition to the existing circuit would suffice or if indeed a new one would be required.

 

[Rob_the_rich]

what machines are they?

Where did you get 23A from? table 4D4A gives for methods C,D or E only 18-19A for 1.5mm multicore 70oC whereas 90oC (4E4A)gives 23A for method C. Are you sure it is thermosetting insulation in the SWA?

 

[Andy™]

even if it is XLPE, you need to ensre all other parts are also suitable for running at XLPE temperatures

 

[Essex1]

what machines are they?

Where did you get 23A from? table 4D4A gives for methods C,D or E only 18-19A for 1.5mm multicore 70oC whereas 90oC (4E4A)gives 23A for method C. Are you sure it is thermosetting insulation in the SWA?

It is still protected by a 16A OCPD so.....

 

[Rob_the_rich]

It is still protected by a 16A OCPD so.....

But he may be tempted to put 20A OCPD in.

 

[Andy™]

which can be done providing the wiring is suitable for the increase for 20a, so valid question to be asked

 

[steptoe]

not only the cable,

but, is the 16a skt he is using rated at 90 as well? possibly not I'd hazard.

 

[MARIOW]

machines are gilotine(use in printing industry) and another one that is comming is die cutter. Circuit protected is by old type "flat ends" fuses (I think they are NSD or ESD called).

I'll run extra cable. As from what I just read its imposible to do it in different way and make it safe.

Thanks to all