Singles in conduit.

[drew35]

I don't usually get involved with singles run in conduit but I'm wiring a workshop and the customer asked for conduit and singles, but he has asked me to do a couple of things which I'm not to sure off.

1. To save cable, instead of running cable down the socket drops and back up, and then along to the next socket, he wants me to use crimps at the top of the socket drop so there is only the three singles down to each socket. I don't like relying on crimps but I couldn't think of a regulation against it?

2. Again to save cable, I'm running three banks of fluorescents and he wants each bank switched separately, from different locations. I was going to run a separate circuit for each bank via a 1g switch. But to save cable he wants me to through wire with the neutral and cpc to all of the lights, then take the live to the first switch and piggyback a live from the supply side on to the next switch. Is there anything wrong with that? Again no regulation sprang to mind, I will go through the book later but any advise is gratefully received.

Cheers.

 

[J@mes]

1. I think crimps have to be accessible if used so I wouldn't want to pull them in to conduit without having an access plate/ conduit box at the top - in which case you could just use connector block or WAGO connectors. Is it going to be a ring or radial? If he wants to save cable then make it a 20A radial and although you'll have the drops/ risers to the sockets, you won't have the return leg to the board. although as you are running it in singles unless it is a huge place he isn't exactly going to save much on cable!

2. Don't think this is any different to looping at the switch instead of at the rose like some now do in domestic situations!

 

[accordfire]

Wagos in a conduit box would be the way to go.

Realistically though, I don't think it will save the punter very much money....what you spend in Wagos, you'll spend in cable anyway.

 

[Adam W]

I would not be happy wiring the power like that.
Firstly because I don't like to see jointed cables on a new install.
Secondly what kind of circuit would that be? Ring? Radial? Ring with all the sockets as spurs (to my recollection the regs only permit one spur for every socket on the ring)?

The way this guy is proposing wiring the lighting seems ok provided you're taking a cpc to all the switches, however I wouldn't feel comfortable working for such a penny-pinching miser.

 

[Richard]

I don't usually get involved with singles run in conduit but I'm wiring a workshop and the customer asked for conduit and singles, but he has asked me to do a couple of things which I'm not to sure off.

1. To save cable, instead of running cable down the socket drops and back up, and then along to the next socket, he wants me to use crimps at the top of the socket drop so there is only the three singles down to each socket. I don't like relying on crimps but I couldn't think of a regulation against it?


2. Again to save cable, I'm running three banks of fluorescents and he wants each bank switched separately, from different locations. I was going to run a separate circuit for each bank via a 1g switch. But to save cable he wants me to through wire with the neutral and cpc to all of the lights, then take the live to the first switch and piggyback a live from the supply side on to the next switch. Is there anything wrong with that? Again no regulation sprang to mind, I will go through the book later but any advise is gratefully received.

Cheers.

1. If you do this, assuming your using 2.5mm it can't be fused as a ring (because it's spured to many times) so you'll have to put a 20A breaker on it. Personally I don't think he'll save any money when you calculate your time for having to terminate so many more cables

2.The way he said seems ok, LOAD depending. With flourecents remember to multiply your total load by 0.8. So if you well under 6A then fair enough.

If you run more than 1 circuit, you can't just one neutral and earth because that one cable could carry way more than 6A and still not trip. I think i'm right in saying each circuit should have a dedicated neutral and earth.

 

[drew35]

Thanks everyone, just confirming what I thought which is good. I was only going to allow him a radial with a 20a breaker, I have a feeling he is a tinkerer and would probably end up breaking the ring given a chance. I made the argument for labour cost verses cable cost, you know what some customers can be like, they get an idea they think is fantastic and just wont let it go.