RCD's On lighting etc

[danny124]

Hi guys wondering if you can help.

I did my 17th update as i took a break from the trade for a few years. I finally go back to my firm tomorrow and its all changed.

Trying to get my head around the RCD stuff.

RCD's on everything now right including lighting thats not capped etc ect

Do we split the lighting on one RCD and sockets on another?
Dont light bulbs lamps when they blow trip the RCD's and then clients are going to get annoyed that either all there lights are out or there whole floor is powerless.

And testing, how do we test RCD's on lighting we arent allowed to do live testing on exposed parts due the the electricity at work regs.

Could someone help me.

Thanks for your time guys

Kind regards

 

[acat]

Split them so upstairs lights are with downstairs sockets and vice versa then use sockets to test RCD or test RCD at CU

Hope that helps


Chris

 

[mnmwill]

RCD's on everything in bathroom, kitchen. Any cable chased into wall at less than 50mm without mechanical protection requires RCD. Split circuits across 2 RCD's on 17th ed CU's, eg on RCD1 put up lights, down sockets etc, RCD2 put down lights, up sockets etc.etc.

Cheers

Matt

 

[danny124]

Thans for the quick reply Chris.. seems the regs havent been thought through just another scheme to make money and make things more complicated.

 

[Phil]

hi danny, if it were a high integrity board you would put the down stairs sockets on one side along with the upstairs lighting, on the other you would have the up skts with d stairs lights. thus giving continuity of service in the event of the rdc tripping. you could also wire the the baord in rcbo`s. dont forget if you were testing the rcd you would be testing the same rcd so you could take your readings at the sockets.

 

[davelerave]

no .incandescents may trip the B type


domestic lighting should work ok with rcds

if rules require 30ma protection- i'd be looking at using rcbos and a number of circuits to reduce 'blackout'

 

[Phil]

http://www.electriciansforums.net/e...ulations/16052-17th-edition-fact-sheet-s.html

 

[acat]

Yep you got it in one the only lights that will cause you a headache are the old strip lights they have a habit of tripping the RCD intermittently so look out for that one when you are pulling your hair out wondering whats gone wrong.


Chris

 

[Phil]

then there is always the old borrowed neutral but thats a different story

 

[acat]

Dont tell him about that one Phill poor bloke with commit suicide


Chris

 

[Phil]

all the fun to come

 

[Graeme Harrold]

Working live is forbidden, however testing live is a different matter. You should be using GS38 test probes, test points should be IP2X min or if there is exposed live parts, then shielded. There are plenty of probe adaptors now for sticking in the lamp socket, earth can prove tricky if you dont want to take covers off.....

 

[cornburn]

I was just hopping on to ask a question about exactly this. How would you go about testing lights on an RCBO? The terminals are deep down in the RCBO and can't get probes in to test at the board, would have to be at a lamp or switch. Problem is I guess to do this by the book you would have to do safe isolation, then set all your probes up on the lamp, then power back up, then test. I can't see how you could do this safely without someone to reset the RCBO as you'd have to keep walking off from the tester to flick the switch back up, and there would be exposed live parts by the tester.

Some RCBOs can be tested at the board but the 6A Wylex NH ones have the neutral in the front screw so the line is about an inch down a hole at the back, no way of getting a probe in. I wonder if safely isolating then screwing a piece of wire into the connector to trail out and clip the tester onto would be acceptable? If all connections were made with the tester with the power off then turned back on to test?

 

[GT1]

I've just done wylex NH board with 4 rcbos. From memory, the neutral and line connect from the top, with access to the terminal screws from the front. I tested off the line screw terminal at the front without any major headache ?

 

[GT1]

And I think GN3 states that testing should be done without any loads connected. So I always test before connecting up the conductors.

 

[Graeme Harrold]

If its that much of a problem, test at a switch. No probs pilling from the wall live, if you have fitted correctly as there should be nothing live to touch with your bare fingers......
Plus the switch should pretty much be one of the furthest outlets in the circuit, its also in easy reach and simple to test. Ad as I said before, get the lamp adapters from Kewtech, makes it all so simple (and safe).....

 

[cornburn]

The 32A for the NH are fine and you can use the screw at the front. The 6A ones have the N and L the other way round though so the screw for the L is about an inch inside the housing and a probe won't get in. I was worried about leaving it live while walking back to reset the RCBO as I have my NIC inspection on Friday and sod's law says he'll want that circuit for the RCD test I have a light adaptor for the L & N but would have to have the rose cover off to get at the earth and leave the tester on the top of a set of steps while I went to the board to reset the RCD. Not sure what the inspector would think of this

 

[GT1]

Which meter are you using ?
Do you still have the plastic tip covers on the ends of the probes which cover all but the very end. ?
My megger had them but they are removed as a norm, unless / until I'm being assessed..!!

 

[JUD]

The 32A for the NH are fine and you can use the screw at the front. The 6A ones have the N and L the other way round though so the screw for the L is about an inch inside the housing and a probe won't get in. I was worried about leaving it live while walking back to reset the RCBO as I have my NIC inspection on Friday and sod's law says he'll want that circuit for the RCD test I have a light adaptor for the L & N but would have to have the rose cover off to get at the earth and leave the tester on the top of a set of steps while I went to the board to reset the RCD. Not sure what the inspector would think of this

The Megger 1553 comes with a long insulated probe that screws onto the switched test probe.

 

[cornburn]

I've got a fluke 1652, and with the little nipple things taken off it still doesn't reach in! Yet another reason why I should have got a Megger. I might stick mine on ebay and get one actually, wonder how much it'd cost for an upgrade

 

[GT1]

Ah... I see why you have an issue now. !
The standard megger probes (without guards) fit into the wylex rcbo's no problem..
Can you not just get some different probes for yours ?