In message , ARW
writes
On 10/12/2019 18:45, Tim Lamb wrote:
In message , ARW
writes
On 10/12/2019 12:14, Tim Lamb wrote:
The builders on the neighbouring construction site demanded a
single phase supply to power their portable tools.
I suppose words beginning F and O are in order but, as I had a
beneficial financial involvement in the development, chose to comply.
The only convenient source is the socket outlets in what was our
garage* (now sold with incomers Friday). 20 year old install, Wylex
40 amp RCD.
*On 3 occasions, something they do before leaving site, trips the
breaker. Not in itself a problem but it also supplies power to the
only* entrance doors! I have taken to leaving a door open while the
site is* active as the alternative is winding the door up using a
very tedious* manual system. Not something I can expect the new owners to take on.
*Communicating *get your tools PAT* checked is difficult as I don't
speak* any Romanian.
*Last job of the day is plug in the chargers and batteries I guess
although I have a 9" angle grinder which will occasionally trip a

*Any ideas?

So RCD tripping but no MCB tripping?

But always at the end of the shift?

I wonder if they are switching stuff off and they are switching it
off with a DP switch.

http://www.beama.org.uk/asset/DD77FF...38A083127CA46/
Page 31 seems relevant:-)

Page 31. Caused by capacitors.

Well that's my best guess fella.
I think their last job would be plugging in the portable equipment
battery chargers. I suppose they would be switching off any other stuff.
Screwfix do a BG. RCD protected weatherproof twin socket outlet. If
I jump about, I can fit one of those on the outside wall and fed from
the main isolator (32 amp HRC fusing I think).



Sounds fine. They are better off with their own access to the RCD.

Right. Job done. Pulling 4mm singles through 20mm conduit on your own is
slow.

Changing a faulty twin socket on the original circuit I managed to
demonstrate that a Neutral/Earth fault trips the RCD:-) (I needed the
power on for the lead lamp so was relying on the MCB for isolation)


--
Tim Lamb