Industrial lighting circuit

[Jm1980]

Hi guys

I have some industrial lighting circuits to wire in a workshop and was after some fresh ideas/suggestions as to how i could best do this.

Have done a few of these before and in the past i have sometimes run radials in SWA cable to single gang socket outlets. The High Bay LED lighting then connects via a normal 3 pin plug fitted with suitable fuse. Doing it like this has allowed individual fusing and easy disconnection of fittings (which was great in the early days when LED's seemed super unreliable).

Sockets were left non rcd but labelled, however being 12 metres up in the air nobody was likely to use them.

New job i have picked up is similar environment. Circuits will be swa wired, ref method clipped direct or on tray. The circuits will run on the metallic girders/structure in the roof however the lights will hang (jack chain) a good 3 metres below this. This is for 2 reasons, firstly the lighting design has indicated this height for the lux level required and secondly, the maintenance team at the site only has scissor lifts that will go so high (they will reach the hanging fittings but not the circuit wiring in the roof). Hence i need a way of extending my circuit down at each lighting point and a method of easy disconnection of fitting if possible.

I have seen similar done with a trailing socket outlet dropped down to lighting points via flex but this always seemed a bit rough to me as I've often seen 'not to be connected directly to the mains' on these sockets. Also now with the RCD requirements on socket outlets being tightened even further this would need a risk assessment to cover i presume? Doesn't seem worth the hassle.

Has anyone come across another way of being able to extend the circuit down for disconnection where the light hangs, preferably one that allows individual fusing? (although this is less of an issue now LED's seem a lot more reliable.)

Cheers

Jim

 

[James]

I have seen pc style trailing sockets used for this type of thing, they are small, rated for 10A load and easy to disconnect.

 

[7029 dave]

Only other product I have seen are the detachable celling roses.

 

[Rockingit]

Wondering if a trailing Trucon 1 solution might work for you - I'll find a product link and post below but basically you could drop a flex lead down from the main run and use a trailing socket/joiner at a drop length that works to be able swap out and replace if needed. You wouldn't have that fused, but tbh I'm not sure the need is there anyway, and you'd have issues anyway guaranteeing that a 3-5A fuse would blow before the reaction time of an MCB/RCBO.

 

[Rockingit]

https://www.neutrik.com/en/neutrik/products/powercon/powercon-true1-top/powercon-true1-top-cable-connectors

They're about the size of your thumb, 16A rated (there are cheaper copies available, some of which are rated at 20A), IP65.

 

[pc1966]

Do they need any specific IP rating?

These are cheap and for lighting (4 pole so PL/SL for emergency lights as well), but maybe an issue of cable types they would clamp:

Greenbrook 20A 4-Way Connector - Screwfix

Order online at Screwfix.com. Useful for all connecting requirements, including downlights, transformers, dimmers and control gear. Ideal for use with emergency lighting. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

 

[Jm1980]

Thanks for the replies guys.

No specific IP rating required, fittings and wiring all indoors.

I like the powercon connectors that Rockingit linked, will be having a look at those. Think the Greenbrook connectors might be an issue with the HO7RNF cable i had in mind for the drops down from the ceiling (and they look a bit flimsy/domestic).

Looking at it again i will probably split fittings up into a few more circuits than i planned so fusing at the fitting is less of a desire.

With the nature of the building and structure, the cabling really does need to be swa. Socket outlets have worked really well for me in the past but with no realistic access to the runs at ceiling height its not a sensible solution this time.

As im not using socket outlets this time how would others wire this circuit? All my calcs work out fine for 2.5mm swa 3 core with a c16 mcb. I need a method of terminating swa at each point so either a galv adaptable box or metalclad backbox with a 2.5mm flex glanded out and dropped down 3 metres to the connector and high bay?

Joints will be accessible if really needed (hire of a big enough scissor lift) but it would be a pain to have any issues with the circuit so how would others best connect the wiring inside the points, wago's would be allowed but what's others experiences of them long term? Current on each circuit will 6A approx

Thanks for the thoughts so far

 

[westward10]

The fastest way to do this is a busbar track, more expensive but you will save on labour with all the separate connections and cable. Some tracks will support more than one circuit again saving on cable.

 

[Rockingit]

As im not using socket outlets this time how would others wire this circuit? All my calcs work out fine for 2.5mm swa 3 core with a c16 mcb. I need a method of terminating swa at each point so either a galv adaptable box or metalclad backbox with a 2.5mm flex glanded out and dropped down 3 metres to the connector and high bay?

Joints will be accessible if really needed (hire of a big enough scissor lift) but it would be a pain to have any issues with the circuit so how would others best connect the wiring inside the points, wago's would be allowed but what's others experiences of them long term? Current on each circuit will 6A approx

I'd have some concerns about the risk of dirt/dust ingress up at that height but you could potentially use 3ch lighting track and just drop a flex outlet off as you need to. Would mean you could just run a 5c SWA up to the start of each length. Alternatively then I think you're stuck with an adaptable box or maybe a 20/25mm conduit 3way and wago's. Or, maybe just using conduit and singles (I'd imagine that they're all long straight runs so no need for many sets?) and take your SWA or HiTuff up to the start of each run, would save on all the glanding time. Only you know the environment and what you're looking at!

 

[lozarus]

Many diffrent ways but one that springs to mind is M20 galv thru boxes woth dome plates to M20 stuffer? Or adaptable boxes with CPC links

 

[Rockingit]

Many diffrent ways but one that springs to mind is M20 galv thru boxes woth dome plates to M20 stuffer? Or adaptable boxes with CPC links
View attachment 111860

Yes, that's basically where I was at only using a 3way instead of the added expense of the dome top - also one less cpc to do.

 

[lozarus]

Yes, that's basically where I was at only using a 3way instead of the added expense of the dome top - also one less cpc to do.

Ah sorry. Confess to having only glossed over the last few replies

 

[Jm1980]

Thanks for the input guys.

Lighting track is out of the question. The routing (h section guirders and angle iron) means that swa cable clipped direct looks by far the easiest way of doing it. Had another look today and i like the galv adaptable boxs with a stuffing gland out for the flex drop.

The 2 way through box and dome top would make the job a little quicker i think but there's something that i think looks ugly about swa into a through box (not that anyone will see it 50ft in the air!)..........i also think with 2 x 2.5 cables and the flex, the through box might start to get a little cramped.

Regarding my question of wago's used at junction points/adaptable boxes............would anyone have any reservations about using? Ive yet to see any joints with wago's that have 'gone bad' but wondered what others thought?

Cheers

Jim