hi,
Testing a job at the moment and a couple of DB have all there CPC connected in the trunking instead of the DB. There is a earh bar within the metal trunking but due to the trunking full of cables, unabale to gain access to the CPC. Due poor access to the CPC ive made a report on that but...
Can someone tell me if an RCD or RCBO, 30ma, will trip on earth leakage if a fault occures from live to the metal case of a switch where no cpc is present ? I think it will as the RCD is looking for an imbalance between line & neutral and this will occure if a person touches the metal switch and...
I was carrying out an r1+r2 today and when disconnecting the cpc out of the earth bar to link worth the line it sparked on removal from the earth bar....
I tested between the cpc and the earth bar and got 120v
Tncs earthing arrangement
I've carried out insulation resistance test and that was...
Hi
I've never posted in one of these forums before, but have read lots of threads and found them extremely helpful.
So it makes sense seeing as I know the knowledge on this sight is very impressive to ask you guys for help.
I have a problem with a job and can't work out what the problem is I've...
Good Evening all,
Been at a property today starting intial tests for a board change tommorow. There are two ring circuits, on one of the ring circuits i had an open circuit on the cpc. Live and neutral where fine 0.4/0.4. I started to locate the break by splitting the legs and joining the live...
Hello just wondering if anyone could help me! I have to test a circuit tomorrow wired in SWA that is using its armoring as its earth, To carry out the R1+R2 test how would i eliminate any parallel paths? Surely the only real way to do this would be to remove the cable from the side of the metal...
Hi all,
A customer wants me to replace a light-fitting and/or light switch for a metallic one, to a lighting circuit with no CPC.
Property must therefore be pre 1966 (ish).
Is this a definite NO-NO.
I would feel very uneasy about doing so.
Ta,
W1ll.
Hi all
Just a quick 1 I'm doing an eicr and basically I've come across 2 pendant fittings with a 2 core flex going to them and no CPC problem is that ceiling has been over boarded with timber panels there's an earth at every other fitting, what code would this warrant.
My friends downstairs sockets are tripping the RCD. First thing I did is unplug everything on the circuit, switched on the MCB and the RCD tripped. Tested continuity of L-L N-N CPC-CPC between the legs. CPC has no continuity whatsoever. Could anyone advise me what would be my next step to...
Hi
If anyone can help,I am carrying out an EICR on part of large hospital and have found voltage that varies between 100 and 200v between live and neutral on one single phase submain cu. It is present when main switch is off so is on load side. Apparently they get voltage around 0v to 60v...
It's been a few years since college and I'm stuck on understanding this,
I'm getting an intermittent fault on kitchen sockets. Causing some tripping.
Broken it down and when I IR test the circuit. L to E is 200+
N to E is 200+
But when I test N&L to E thruster fluctuates between 120Mohnm to...
Is there a reference guide for which SWA sizes can be used as the CPC? I have a 120mm 4core SWA at 110M and although the Zs value has been measured at an acceptable value our electrical insurance inspector wants all SWA cables above 16mm on site (industrial premises) to have a seperate earth...
Been asked to swap over a class 1 fitting for another old existing class 1 on a first floor hallway - however there is no cpc on the light circuit! (early 1960s house). In the loft there is a rfc junction box close at hand. What about putting a 4mm g/y single from the light fitting to the J.B...
I'm doing a mod for a 3 phase circuit already installed. The only trouble is I can't work out why the existing cables are as they are so i am doubting my sums.
Existing final circuit.
3 pole memshield 2, D32 rated feeding 10mm2 4 core swa with a seperate 16mm2 G/Y as cpc.
Measurements at the DB...
Just running thro some design calcs for minimum cpc size and im getting some unrealistic readings. Example 1.5mm c.s.a live and 4.mm cpc on a lighting circuit?? circuit is Zdb = 0.083
Circuit 1L1
Assuming we can use 1.5mm cpc
R1 + R2 = (12.10 + 12.10) x 1.2 x 3.57 / 1000 = 0.10ohms...
I'm looking at the options for customer who has no CPC on lights as is quite common. I know the ESC "good practice guide" - and that all makes good sense.
However most light switches with exposed screws into metal back boxes (where metal box is unearthed because no CPC), would therefore be...
Hi all
Been asked to quote for a board change. Had a quick look round the place and discovered lighting circuit has no earth. Where do I stand on this?
Current board is 3036s and will be replacing with rcbos as wiring is quite old. Will also be bonding the gas and water from 4mm to 10mm.
Had to leave a job early tonight, so couldn't resolve what should be a simple issue, but now it's buzzing round my brain. I have 5 ceiling rose's and pendants in a good old loop system. All 1 Way. I have good continuity readings at rose numbers 1,2,3 and 5. I have good continuity...
Hi all, looked at a job today to replace 5 x single sockets to 5 x doubles. Looks like the CCU was changed maybe 4 or 5 years ago but no paperwork - the property has the old wiring in place - red, black and unsheathed cpc. The single sockets are only 4 inches from floor level so i will need to...
I was reading the latest issue of the NICEIC’s Connection magazine, when came across an article about wiring extractor fans. I didn’t read it in depth (was in the library at the time!!!), but from what I can gather you can now use the cpc in a flex (flex only, not hard wired) as a live conductor...
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