When selecting a CPC, do I round up or down? For example, if I have 120mm2 actives do I select a 50 or 70mm2 earth? If a have 150mm2 actives, is 70mm2 enough?
I've come across a house whereby the redundant immersion heater circuit (15A) has had it's CPC repurposed as a means of bonding the incoming water supply in the same cupboard. Irrespective of the CPC being undersized is this, in theory, allowed or must the earth bonding be clearly identifiable...
some time back a customer rang up saying a tenent was getting shocks from a shower .Investigation revealed the problem lay with a broken cpc (caused by new insulation installers) resulting in a voltage of approx 27 v on the metallic parts of the shower .However the finger of blame was initially...
Hi,
I am struggling to understand one concept if anyone could shed some light.
as TNCS has combined neutral and Cpc so if on the consumer side hypothetically if you check continuity on N+Cpc without disconnecting any conductor, do we get continuity of Neutral and CPC as on the supply side, its...
In a former life on another forum as well as this one.... there were a whole heap of downloads that people had done as ready-reckoners for things like Cu eq for various armour sizes, R1R2 values on lengths.. useful stuff. I think I might even have generated some myself.
Anyone have any...
I have been asked to wire up a new extension for a customer and during testing prior to starting I have found that both upstairs and downstairs lighting circuits have no cpc's. However, upon further investigation it appears that the downstairs lighting circuit has managed to "borrow" a cpc from...
Hello, I have been asked to do a eicr on a property that I have found to have no CPC in the lighting circuit. Just wanted to know if this constitutes a c2, or vat best c3. Thank you in advance
Hi
I have reviewed a few posts around this subject, but my question is not covered. I know that the Submain Earth has to be sized on the DNO incomer, not on the submain to the external building itself. My question is if I need two main bonds in the submain building, for example one for ground...
Morning All,
Currently carrying out an EICR and going through ring final steps with the following readings:
r1: 0.31ohm
rn: 0.32ohm
r2: 0.03ohm
Started taking sockets faces off to find that there is no cpc, only fly lead to metal patress box and steel conduit trunking. (See photo)
When i...
Come across an old Installation with 1.5mm CPC on a 6mm Live conductors whilst doing an EICR. Not seen many of these, in everyones opinion perfectly acceptable if all R1 and R2, IR, Measured ZS test check out ok?
Just got back from looking at a potential job. What a bodge up!
I was called around to be asked to install an isolator for a sub main feeding a consumer unit which a car charger company will come off feeding their charger.
New mains upgrade recently done and the previous electrician has bodged...
IEC 60364-5-54 states that phase conductors 16mm2 and smaller require a CPC of the same size, over 16 to 35mm2 a 16mm2 CPC and over 35mm2 a half size CPC is required.
My questions is why am I seeing catalogs with harmonized twin and earth with reduced size CPCs over 2.5mm2? And why doesn't the...
What is the current position with installing a replacement consumer unit, where there is no c.p.c. Can the existing cable remain according to the regulations, by placing a label at the C.U. warning against fitting metallic fittings?
Hi guys
I was putting in a spur socket at a friend's house. when i noticed that the CPC is the metal cable trunking. I understand this is within regulations. However upon testing it had a high earth loop impedance and likewise r2.
My question is, is it acceptable to run in a new CPC from...
Good evening
following a visual inspection in a property that had an electrical fire in the fuse board area
obviously i could not actually test anything, but visually identified that the lighting circuits had no earth (not even cut back)
now the insurance company ideally want a new...
So had a call out last night to a house late night the lights had all tripped.
Had 2 lighting circuits in one breaker one with a dead short on it and the other is fine.
While i was there I also discovered there was 110v in one leg only of a cpc serving a final ring circuit but its not tripping...
Can anyone please help me, HOW to Calculate R1+R2 on 4 core three phase & neutral SWA, Armour Steel Sheet is Used as CPC. How to fill the Electrical Installation Form. This scenario is in AM2 Inspection and testing filling Certs Exam? Please reply with best answers.
Any members those who took...
I have been asked to give a quote to install some downlights in a kitchen, but there is no cpc in the light circuit. I appreciate the response by some is the world would end if I did that, but the circuit is RCD protected and the last IR readings on the ciruit were good when the board was...
Done a periodic on this a few weeks ago and back now doing remedial. This notice and the previous Report state there are no cpcs through the lighting. None of the roses have a cpc connected but there is at the conduit boxes they are mounted on in fact I have checked every light and there is a...
Hello,
Just getting ready for my first scheme assessment and am completing a board change to be assessed on.
Ground floor ring end to end readings. Its a 2.5mm ring T+E
r1 0.71
rn 0.72
r2 8564
I have had all of the sockets off to check for a loose connection.
The property has over the...
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