16-10-2015, 05:19 PM
New thread on this to save cluttering Ex " Base's thread:
Jeffery wrote...."Not sure if I've interprested this corerctly but are there cascaded RCDs in the feed to the shower? I explained the problem of cascaded RCDs and discrimination in post #11.
I think you may also have discrimination problems between the MCB for the shower and the MCB at the house end of the armoured cable. This is mainly a convenience issue rather than a safety one, except that if the house end MCB trips due to a fault on the shower you're left in the dark."
Jeffery, I made a mistake in the description of the set up in Ex 2 Base's thread, the 4 way consumer unit in the caravan does not have an RCD in it just the 4 MCB's (I previously said it did)......At the house end the armoured cable feed to the caravan is via it's own MCB and an RCD which also protects the other circuits in that half of the split box which supplies the armoured cable, here's a pic of the caravan consumer unit:
Anyways, got to City Electrical early this morning and bought a reel of 10 mm earth cable, got back and exposed the plastic water pipe ducting at the caravan end, the draw string was run through it when I installed the duct some years ago, here's a pic showing the caravan end ready to rock and roll:
Pic showing part of the path the ducting is buried under, the ducting terminates under the DPM of the floor of the white rendered part of the house:
When I did this floor some years ago I fitted a small section of removable floor board and a 2" slot in the concrete above where the duct terminates under the under floor slab insulation and DPM, a quick hack with the bread knife to remove a bit of the slab insulation and quick slit in the DPM to expose the said ducting and draw string:
With Mrs Hillbilly pulling and me feeding it took about five minutes to get the earth bonding cable through, the floor battens stop short of the wall by 1", the box skirting around the radiator is removable as is the rest of the box skirting that runs around to the electricity cupboard:
Caravan end bonded to the hot & cold water water pipes, house consumer unit end connected to the earth busbar, the earth connection next to it on the busbar is the earth incomer.
I hope all this is ok...??
To recap...at the house consumer unit, RCD...MCB...armoured cable...caravan consumer unit (4 way) and also feed to shower unit which has its own RCD and MCB (that's how the shower unit came)
Separate 10 mm earth bonding cable connected to the hot and cold water pipes in the caravan, and connected to the earth busbar in the house consumer unit.
Lawrence.
Jeffery wrote...."Not sure if I've interprested this corerctly but are there cascaded RCDs in the feed to the shower? I explained the problem of cascaded RCDs and discrimination in post #11.
I think you may also have discrimination problems between the MCB for the shower and the MCB at the house end of the armoured cable. This is mainly a convenience issue rather than a safety one, except that if the house end MCB trips due to a fault on the shower you're left in the dark."
Jeffery, I made a mistake in the description of the set up in Ex 2 Base's thread, the 4 way consumer unit in the caravan does not have an RCD in it just the 4 MCB's (I previously said it did)......At the house end the armoured cable feed to the caravan is via it's own MCB and an RCD which also protects the other circuits in that half of the split box which supplies the armoured cable, here's a pic of the caravan consumer unit:
Anyways, got to City Electrical early this morning and bought a reel of 10 mm earth cable, got back and exposed the plastic water pipe ducting at the caravan end, the draw string was run through it when I installed the duct some years ago, here's a pic showing the caravan end ready to rock and roll:
Pic showing part of the path the ducting is buried under, the ducting terminates under the DPM of the floor of the white rendered part of the house:
When I did this floor some years ago I fitted a small section of removable floor board and a 2" slot in the concrete above where the duct terminates under the under floor slab insulation and DPM, a quick hack with the bread knife to remove a bit of the slab insulation and quick slit in the DPM to expose the said ducting and draw string:
With Mrs Hillbilly pulling and me feeding it took about five minutes to get the earth bonding cable through, the floor battens stop short of the wall by 1", the box skirting around the radiator is removable as is the rest of the box skirting that runs around to the electricity cupboard:
Caravan end bonded to the hot & cold water water pipes, house consumer unit end connected to the earth busbar, the earth connection next to it on the busbar is the earth incomer.
I hope all this is ok...??
To recap...at the house consumer unit, RCD...MCB...armoured cable...caravan consumer unit (4 way) and also feed to shower unit which has its own RCD and MCB (that's how the shower unit came)
Separate 10 mm earth bonding cable connected to the hot and cold water pipes in the caravan, and connected to the earth busbar in the house consumer unit.
Lawrence.
