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Carrying out a few consumer unit replacements at a hotel, installation to the room is via trunking conduit with no cpc however at the rooms previous refurbishments have been carried out these being wired in Twin and earth with the cpc being connected to the existing system. Now I am not sure what to record as the R1+R2 results do I add a limitation or calculate from the Zs Ze readings and state that's what I have done?
 
If there is no CPC then you really need to be dealing with that situation first!

However if what you mean is that the trunking/conduit is the CPC then you just measure the R1+R2.
 
Sorry should have made that clear, the trunking and conduit installation is steel and up to the rooms is the CPC. I was of the opinion that the R1+R2 results would be meaningless to a point because of all the parallel earths? Thanks for your reply BTW
 
Carrying out a few consumer unit replacements at a hotel, installation to the room is via trunking conduit with no cpc however at the rooms previous refurbishments have been carried out these being wired in Twin and earth with the cpc being connected to the existing system. Now I am not sure what to record as the R1+R2 results do I add a limitation or calculate from the Zs Ze readings and state that's what I have done?

One thing you never do is calculate a R1 + R2 this always needs to be measured. Get your meter out ant test either R1 + R2 or else R2. I would be concerned as how the cpc's in the twin and earth are connected to the containment system.
 
One thing you never do is calculate a R1 + R2 this always needs to be measured. Get your meter out ant test either R1 + R2 or else R2. I would be concerned as how the cpc's in the twin and earth are connected to the containment system.

Thanks for your reply. within the room there is a steel skirting trunking the socket outlets being earthed via a fly lead lugged and bolted through the trunking. The bedhead lighting is fed via flex outlet plates fixed to the trunking and flexes up behind the bedhead to the light fittings. The bathroom has a some point been refurbished and is wired in T&E to an adaptable box behind a bulkhead above the bathroom sink. the adaptable box is inaccessible but I can see that the CPC is lugged an bolted to the box not ideal I know but the Hotel is not about to let me remove all these bulkheads to access the box. The distribution is in a central location in the corridor the furthest room being approx. 25m from this location. Because the Hotel is occupied I am trying to minimize the amount of time the rooms are out of service and to test in the quickest and most accurate way. I will likely do as you suggested and carry out an R2 test and add a limitation to the test certificate for the R1 and R2 readings. There in total 26 distribution boards to replace throughout the hotel these being Simplex and fitted with 30a and 5A type 4 3871 mcb`s. This is part of the remedial works that comes from a fixed wiring inspection by the insurance company and mainly involves installing RCD protection to the room/bathroom circuits. At the moment I am carrying out this work on my own and as I wrote above trying to minimize the inconvenience to the Hotel.
 
You shouldn't need to remove all the bulkheads. Sample them there could be MF joints in there. If that's why you wouldn't to remove them?...

An R1+R2 doesn't have to be made up of cable only, it could be containment if that's whats been used. Do your R1+R2 or R2 as you usually would. Using a wonder lead your still measuring the same earth path just minus line conductor of course. There's no need for any limitation you either use method one or two and N/A in the box not used.
 
P.S 26 distribution boards to replace?! Is that necessary?...
I`m not looking too hard :) The report says the type 4 mcb`s are obsolete and I believe they need a current in the region of 50xIn to operate but its mainly because of the lack of RCD protection to the rooms and public areas and you cannot get RCBO`s or pods to fit these. The original installation was conduit and trunking throughout and is still sound but there have over time been so many upgrades to the installation and these have been carried out in T&E for the most part so RCD protection comes into play within the fabric of the building as well. Thanks for the reply which confirms my intended method of testing this job.
 

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