- Reaction score
- 27
EICR: I’ve come across 30mA RCD supplying a consumer unit via a 63A MCB and 16mm T&E. connected via an isolator to the cutout PME. (Ground floor, outside meter cab on wall)
The T&E is concealed up the stairwell behind /within plaster into a 1st floor flat above a shop and into the CU so effectively has 6mm main earth.
(see pic for the bodge of an install of the RCD which has been wired incorrectly but functions - what would you code that ! )
The CU is a dual 30mA split load affair. Therefore no selectivity and any earth fault will likely trip the whole supply, as it did on RCD test
In addition NO bonding to gas or water which is another matter but related of course
I see options as below sny
1. rewire submain cable with SWA or surface mount with T&E (costly/messy/unsightly either way)
2. Replace Supply RCD with switch fuse but this breaches requirement of 30mA RCD for concealed cable -
3. Accept the selectivity/nuisance factor but the RCD supplying T&E is in an outside meter box with a lid that actually needs a tool to open
4. replace Supply RCD with time delay 100 mA RCD which does not comply with concealed cable requirements
4. submit EICR and leave for someone else to resolve !
The T&E is concealed up the stairwell behind /within plaster into a 1st floor flat above a shop and into the CU so effectively has 6mm main earth.
(see pic for the bodge of an install of the RCD which has been wired incorrectly but functions - what would you code that ! )
The CU is a dual 30mA split load affair. Therefore no selectivity and any earth fault will likely trip the whole supply, as it did on RCD test
In addition NO bonding to gas or water which is another matter but related of course
I see options as below sny
1. rewire submain cable with SWA or surface mount with T&E (costly/messy/unsightly either way)
2. Replace Supply RCD with switch fuse but this breaches requirement of 30mA RCD for concealed cable -
3. Accept the selectivity/nuisance factor but the RCD supplying T&E is in an outside meter box with a lid that actually needs a tool to open
4. replace Supply RCD with time delay 100 mA RCD which does not comply with concealed cable requirements
4. submit EICR and leave for someone else to resolve !
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