Certification for room electrical.

[northwest]

Hi all. For those who have done an arcade room man cave building, did you use a part p electrician etc or did you do it yourself and get checks done later ? Trying to find out but seem to find conflicting notes online. I am aware of rcd and conduit and armoured cable to be used ( will be an outbuilding end of garden ) . Was hoping to do myself the cable laying and get someone ( works engineer ) to do connection. He is not domestic part p self certified though ? Will be going from mains board in house on junction box to RCD board in outbuilding via armoured cable. Once all this is complete I would look at getting an electrician to do tests and give a pass hopefully, but been told it doesn't work like that . Couple of electricians stated they need to do it from start to Finnish to pass and confirm to building regulations and application.
...... Or did some of you just say bolox I'm doing it and saying nothing . Don't want to get stuck incase at later date we sell house ,not looking anytime though .
Any advise please .thanks

 

[RGP]

Utter bollox!

You can do your own dry install as long as you know the regs involved - they're just after a labour fee.

Any decent sparky will do your end hookup and certificate.

Part P was invented to get the cowboys to stop tampering with household electrics, doing it wrong and causing a fire.

You already know you need SWA at bare minimum to your outbuilding.

So in the ideal world, you'd have a breaker dedicated to this feed in your house on your primary distribution board which terminates at a garage consumer unit which would have an MCB for the main input and then at least 1 x 6A for the lighting and 2x16A for the sockets. By the looks of your post you already know about the board in the outbuilding so give it its own breaker in the house.

You run both your lighting and sockets in a ring configuration, check all your earth continuity all the way along.

You can even as a DIY installed go as far as doing a temporary termination to a standard mains plug and use a plug top tester and light-fixture tester to make sure all your phase is correct and earth is good and then let a sparky hook it into your main board.

Sounds to me like you know what you're doing anyway.

 

[northwest]

Hi, thanks for info. The plan ( my thoughts , but not definite) was to take the tails that goes from main fuse to the distribution/ main board in house to an purpose high supply junction box from there would give 2 sets of tails ,one to the main board and one set to a circuit breaker that would have armoured cable to rcd board in outbuilding. I didn't think about just having a dedicated breaker on main board , 40 amp maybe ? Correct if I'm wrong please .
As it is I am looking at changing the house main board anyway as it's on 2 rows each with RCD supplying 9 breakers in total. Wanting to split them down more to isolate rooms/ lighting. So been checking out likes of a 12-15 .thanks

 

[penrhos]

I did Part-P years ago when wires were red/black/green and you still found Bakelite fittings.

When I had the garden landscaped a supposedly qualified electrician wired it all up and certified it. Within a month I had to get them back as the main RCD was tripping. I'd run in SWA to the shed at the same time and they were adamant it was my work that was causing the problem, I said fine - prove it and I'll pay your costs & any remediation costs.

All the readings on my install came back perfect - turns out their "qualified" electrician hadn't fitted the rubber seals on the IP65 junction boxes feeding the garden lights so they'd filled up with water. A couple of months ago I was planting an apple tree in the lawn and hit a piece of SWA - turns out they'd run the cable diagonally across the lawn only 6" down with no protective cover or warning tape.

When I wired up the shed I laid drainpipe with draw-ropes in in a bed of gravel then put some broken paving slabs over the top and two layers of warning tape - the hole was 24" deep as per the regs.

If burying SWA don't forget it de-rates the cable so you need the next size up for the Ampage.

How I connected it up was to have a junction box in the garage - the SWA terminated in it via a Gland, I ran Twin & earth mains ring to the junction box and got someone with an up to date Part-P to connect the tails to the distribution board and fit an 20A RCBO in the unit. In the shed I had the same setup, a junction box to terminate the SWA and twin & earth ring to a sub-DB with a 13A RCD for the sockets & a 3A one for the lights. I used 32A rated SWA for the feed.

 

[northwest]

Thanks for that . The new house cu will likely be all rcbo , just to clarify ,you fitted the 32a swa directly to the house unit ? Or to junction box with gland and then to 20 rcbo in house cu . Was an RCD needed in the shed unit as you already supplied the unit via rcbo though ? Once this is all done I'll get it connected and certified separately by a different electrician to those I've spoke to last week. Thanks

 

[philmurr]

Part P has been much relaxed since its last release. Although all wiring should still be to the latest edition of BS7671 (the wiring regs) and some of what you're suggesting isn't.

Having seen a number of dangerous installations, if people aren't sure they should get a qualified electrician in

 

[northwest]

Fair point and very true. But better taking advise what is expected of work to be carried out,or I miss like you stated mine suggested isn't on the edition. Especially when from my findings these electricians are on £200 a day rate.id like to do what I can or at least permitted . But thanks anyway for input.

 

[RGP]

Having seen a number of dangerous installations, if people aren't sure they should get a qualified electrician in

Sums up everything perfectly.

I'm not a qualified electrician but have had to ingest the regs. We deal with temporary power on event sites and you should see some horror stories there. People sometimes don't maintain their backbone cables and sleeving starts to come away from 415v connectors.

There's always a head electrician where we work and we confirm our work plan and load calculations with them ahead of the show.

 

[penrhos]

I used standard ring-main rated twin & earth from the Fusebox to a junction box where I connected it to SWA using 32A rated terminal blocks (as you shouldn't connect SWA to the fusebox). The SWA was then run to the shed where I reversed the process (you could fit the SWA into the sub-board to save a joint. the whole spur was protected by an RCBO.

I used a 20A RCBO and 32A SWA (you should de-rate by at least 20% if SWA is buried in soil).

 

[northwest]

Sounds good. Something I'll look at doing that route as planned anyway , I'll leave all unconnected but get it connected and tested etc by electrician . Saves money on paying them huge money to dig a trench only for them to pay minimum wage on their labourer to do it. Thanks for input.