Commercial premises electrics questions

[MattH]

To all the sparky's out there.

Our new business unit has a Hager 3x100A distribution unit.
It was previously occupied for a long time by a mechanic.
There seems to be years of bodged on electrics, loads and loads of double sockets spurred off original MK sockets with T&E stapled to the walls, metal clad boxes with plastic faceplates, odd MCB's in the board, lighting spurred off all over the place etc etc etc.

There is a single run of 3 phase to an isolator that was for the ramps. I need to use this and another 32a socket ASAP for my first cnc and vacuum pump.

Question is: what are the regs around installing new circuits and cleaning up the existing ones?

I will probably get a spark in to install the new 32a 3 phase circuit but really I'd like to refresh all the wiring. At this point I can't see the funds being available for this but I would happily run SWA around the entire unit up high with drops down to new MK metal sockets and a few 16a and 32a circuits, maybe leaving a spark to do the final connection and MCB installations.

Would this be ok? I have not idea around the regs regarding commercial units.
FYI I trained as an Electronic service engineer years ago so should be considered "competent".

Here's a pic of the board currently (didn't get a pic of the whole unit but there's no RCD just a triple 100a isolator at the bottom):

 

[Wendelspanswick]

Being classed as 'competent' is a grey area but completing the C&G 2382 meets the minimum requirement in the eyes of the law.
If you are happy with your level of knowledge then go for it but if I was in your position I would get a copy of the regs or at least the Onsite Guide and make sure you understand and perform correctly the dead and live tests on your circuits.
If you get a sparky to finish off your circuits find one before you start work to discuss what installation methods he will sign off on.

https://www.tlc-direct.co.uk/Products/BKPOSslash3.html?ad_position=1o1&source=adwords&ad_id=45425533757&placement=&kw=&network=g&matchtype=&ad_type=pla&product_id=BKPOS/3&product_partition_id=120630398477&test=finalurl_v2&gclid=CjwKEAjwxce4BRDE2dG4ueLArHMSJADStCqM_yovvCxi8Jt-7Jbv71GKmU7YkrSgaO0mZYxtolY3ARoCnivw_wcB

There is a good series of videos on electrical testing:
Electrical Installation Testing: http://www.youtube.com/playlist?list=PLSVLgJeK7oWvP9rycMH4Cfp-EwEMz-KN0

 

[WorkshopChris]

As above being non domestic the part p nonsense does not apply.
If you work to the latest regs, i think the book is about £70.00 it will give you all the info you require.
When choosing your electrician, ask lots of questions. You want someone with industrial experience.
I have seen some truly shocking work done by new trained electricians who have virtually no experience working with 3 phase.
Including one installation where he just fitted 3 domestic consumer units then ran a breaker on each board for each phase of a machine.

 

[Robotstar5]

Haven't seen your unit/workshop, but I would go with a run of metal trunking round the top of the walls and trunking down to the board. You can then drop to sockets etc and go up to lighting with metal/plastic conduit or SWA. The trunking also allows future changes much easier.

 

[Spark plug]

As robo says if you can run a metal trunking right around the perimiter walls, this is what I wished I had done in my workshop.

But before you start, consider how many 3 phase supply's you are likely to need as that board will only support 6 not leavening anything for your single phase stuff.

I fitted an 8 way board in my workshop thinking I would never fill it, then I filled it so I fitted a 6 way alongside now that is just about full also.

 

[MattH]

Good advice from all you chaps. I'm about to pop down there to measure up so I'm going to take some more pics of the electrics. In a perfect world I would love to trunk all the way around with drops for everything. Weather I have the time to do that before I'm in there and up and running is another story.

 

[Spark plug]

If you want to get up and running but also want to make a good job of the wireing you could build an MDU (mobile distribution unit) out of what ever you can beg borrow and steal.

 

[MattH]

Here's some electrically horrors for you all to enjoy:


Lights spurred off spurs, spurs off sockets, conduit falling apart:



Dogdy wiring to water heater, thus feeds two double sockets on the other side of the wall!



Double socket hanging from twin and earth up in the rafters:

Incorrect MCB's, earth wrapped in tape, red wire hanging free made "safe" with some tape (is this a circuit return? Who knows).

 

[WorkshopChris]

That doesn't look to bad have seen much worse.
Looking at that you could probably use that existing trunking for the lights and some of the conduit drops.
1st job, try to see what switches what. Then decide what would be safe/ok to keep then.
When i first moved in to my last workshop you could only put the lights on with the main switch, the light switches didn't do anything lots of live wires literally hanging off the wall/ceiling where sockets and lights had been ripped out.

Spent a long day sorting it, ripped everything out including the board put a couple of sockets on a temporary rdc supply for floodlights and transformer.
Once lights and a few sockets sorted then just put new runs in as machines were ready.

 

[MattH]

As people have said I think I will run 4" Galv trunking all around the unit with Drops for sockets and risers for lights (going to replace all the luminares with Anti-corrosive/weatherproof units).
The only real decision is how to route the trunking over the roller door and back to the DU.

At this point though it's just a matter of doing enough to get in and up and running (should be getting the big CNC in on Tuesday).
I will probably add a temporary new 32a outlet for the vacuum by running a length of SWA back to the DU and adding another MCB.

Once in and settled a bit I will start to add all the new stuff along side the old and then have a switch over at some point.

 

[Spark plug]

To get past the door, hang a length of uni strut from the rafters with m10 stud bar the bolt the trunking to it simples.

 

[Robotstar5]

The only real decision is how to route the trunking over the roller door and back to the DU.

In the last picture it looks like there is a trunking run across the door, use that or follow the same route with a new one?.

Use Spark plugs suggestion of unistrut or drop hanger supports from the roof beams to carry the trunking.

 

[MattH]

What's above the door now is unistrut for lighting. It doesn't go all the way across to the other wall. It's a shame really, the unistrut looks like it ran all the way down the unit in two parallel runs hung from chain. It looks like the last tenant chopped it halfway down the unit so it wouldn't be in the way of his two post lifts and then just hooked into it with flex which is run to all the lights he added to the walls.
I wish the original hung lighting was still there and complete.

 

[MattH]

This shows it: the second run of strut is above the small office he built and has loads of wires hanging down.

 

[Welderpaul]

If your renting it it is the landlords responsibility to make sure the electrical system, among other stuff, is safe and fit for purpose.

When we got ours 8 years ago he ended up ripping the lot out and rewiring it. He might only put the basic in but at least its a sound start to extend from.

Tell him to sort it?

 

[Robotstar5]

This shows it: the second run of strut is above the small office he built and has loads of wires hanging down.

Is it Unistrut or lighting trunking? there's a big difference in use.

 

[MattH]

Probably lighting trunking.

Paul, you're probably right. His words were "we supply you with everything up to the board, beyond that it's nothing to do with us".

Right or wrong I haven't got time to argue the toss with him. And I'm not really bothered about putting it right. At least it will be exactly what I want.

 

[WorkshopChris]

His words were "we supply you with everything up to the board, beyond that it's nothing to do with us".

That's getting a very common option now.
As the landlords have to re do everything each time units change hands.
Saves any arguments later on as well over what has to be reinstated.

 

[Robotstar5]

That's getting a very common option now.
As the landlords have to re do everything each time units change hands.
Saves any arguments later on as well over what has to be reinstated.

When we moved out of a factory unit, we stripped out everything back to the busbar system in the roof, all the SWA and copper gas pipe made a few bob when we weighed it in

 

[MattH]

Just want to say thanks for all the helpful replies so far guys.
Love this place.