- Reaction score
- 1
Hello there all, I'm a fairly newly qualified electrician and have been doing more and more EICRs lately, if someone could actually trawl through my long question and answer it then I shall be eternally grateful
I have tested 3 electrical installations in the last week with no RCD devices, all other tests have come back ok. To be completely truthful I want to sell them all a brand spanking new consumer unit, yay, but I'm a legitimate kind of guy and want to sell them legitimately! So I've just been putting down the appropriate c3s on the report and recommending an upgrade in the name of safety and 1/3 have taken up the offer.
It has come to my attention that I have not been testing the bathroom supplementary bonding correctly in the bathroom and essentially I need to be using the R ≤ 50V/Ia, so in the case of a towel rail immersion heater being present on a 32amp MCB I should be getting less than, 50V/32amps = 1.56ohms between any exposed or extraneous parts in the bathroom which leads me to my main question, if I get a higher result than this (assuming that the extraneous item is also less than 22kohms resistance to the MET, this matters right?) then suddenly we're dealing with a c2 situation which would result in an unsatisfactory condition of the EICR due to the combination of ineffective supplementary bonding and no RCD in a special location.
Also where supplementary bonding can be seen 0.05ohms is the maximum reading between parts in the bathroom?
NEXT QUESTION
If I then upgrade their consumer unit so they have RCDs but the resistance between the the extraneous and conductive parts in the bathroom is more than 1667 (Resistance ≤ 50V/0.03mA) but less than 23Kohm (230V / 22000 ≤ 0.01mA and therefore not a life threatening electric shock) do I still need supplementary bonding even with RCD??!
Where supplementary bonding can be seen 0.05ohms is the maximum reading between parts in the bathroom?
The reason I'm thinking that I still need the supplementary bonding with the RCD is regulation 701.415.2 where supplemenatary bonding can be omtted on 3 conditions, one of which is (vi) where is states: All extraneous-conductive-parts of the location are effectively connected to the protective equipotential bonding according to 411.3.1.2.
NOTE: The effectiveness of the connection of the extraneous-conductive-parts to the location to the main earthing terminal may be assessed, where necessary, by the application of Regulation 415.2.2
Which is just the regulation explaining the need for R ≤ 50V/Ia.
Thank you very much and I bloody hope that makes sense or I've been barking up the wrong tree all morning
I have tested 3 electrical installations in the last week with no RCD devices, all other tests have come back ok. To be completely truthful I want to sell them all a brand spanking new consumer unit, yay, but I'm a legitimate kind of guy and want to sell them legitimately! So I've just been putting down the appropriate c3s on the report and recommending an upgrade in the name of safety and 1/3 have taken up the offer.
It has come to my attention that I have not been testing the bathroom supplementary bonding correctly in the bathroom and essentially I need to be using the R ≤ 50V/Ia, so in the case of a towel rail immersion heater being present on a 32amp MCB I should be getting less than, 50V/32amps = 1.56ohms between any exposed or extraneous parts in the bathroom which leads me to my main question, if I get a higher result than this (assuming that the extraneous item is also less than 22kohms resistance to the MET, this matters right?) then suddenly we're dealing with a c2 situation which would result in an unsatisfactory condition of the EICR due to the combination of ineffective supplementary bonding and no RCD in a special location.
Also where supplementary bonding can be seen 0.05ohms is the maximum reading between parts in the bathroom?
NEXT QUESTION
If I then upgrade their consumer unit so they have RCDs but the resistance between the the extraneous and conductive parts in the bathroom is more than 1667 (Resistance ≤ 50V/0.03mA) but less than 23Kohm (230V / 22000 ≤ 0.01mA and therefore not a life threatening electric shock) do I still need supplementary bonding even with RCD??!
Where supplementary bonding can be seen 0.05ohms is the maximum reading between parts in the bathroom?
The reason I'm thinking that I still need the supplementary bonding with the RCD is regulation 701.415.2 where supplemenatary bonding can be omtted on 3 conditions, one of which is (vi) where is states: All extraneous-conductive-parts of the location are effectively connected to the protective equipotential bonding according to 411.3.1.2.
NOTE: The effectiveness of the connection of the extraneous-conductive-parts to the location to the main earthing terminal may be assessed, where necessary, by the application of Regulation 415.2.2
Which is just the regulation explaining the need for R ≤ 50V/Ia.
Thank you very much and I bloody hope that makes sense or I've been barking up the wrong tree all morning
