- Reaction score
- 17
Now this is a bit of a head sratcher. I've been called to a property where the RCD (used as main incomer) trips at exactly the same time every evening (7.50pm). Some work has been carried out recently at the property by another electrician. He installed new wiring via a 2 way stand alone C.U. also with a RCD as incomer fed from a Henley block which splits the supply between the 2 boards. The existing C.U. has just 3 circuits.
My initial thoughts were that something was coming on in the house at that time whether it be an o/s light, boiler, plug-in timer etc but all these possibilities have been iliminated. The RCD (30mA old style Steeple) failed the ramp test and also x1 & x5 tests so it'll have to be changed but not sure if failing these tests are significant anyway.
Iv'e done IR across all circuits, and got all the zero's across E-N with the lights cpc connected to the earth bar, all the nines with cpc disconnected. All other circuits checked out fine. Left cpc disconnected over night but still the RCD tripped at 7.50pm.
Western Power have been and had a look on their side but could find nothing unusual (I wasn't there, this was according to house owner).
Earthing is TT.
Customer insists there is nothing connected that would come on at the time stated, there's no immersion just a combi boiler that's not timed to come on, in fact at this time of year it's just used for instant hot water. Customer says that this problem began after the last electrcian finished but I'm not sure the two events are related.
Anybody got any ideas?
My initial thoughts were that something was coming on in the house at that time whether it be an o/s light, boiler, plug-in timer etc but all these possibilities have been iliminated. The RCD (30mA old style Steeple) failed the ramp test and also x1 & x5 tests so it'll have to be changed but not sure if failing these tests are significant anyway.
Iv'e done IR across all circuits, and got all the zero's across E-N with the lights cpc connected to the earth bar, all the nines with cpc disconnected. All other circuits checked out fine. Left cpc disconnected over night but still the RCD tripped at 7.50pm.
Western Power have been and had a look on their side but could find nothing unusual (I wasn't there, this was according to house owner).
Earthing is TT.
Customer insists there is nothing connected that would come on at the time stated, there's no immersion just a combi boiler that's not timed to come on, in fact at this time of year it's just used for instant hot water. Customer says that this problem began after the last electrcian finished but I'm not sure the two events are related.
Anybody got any ideas?
