Evening gents & gentesses, PLEASE if anyone has any ideas on the following it will save me either from madness or an extreme night of drunkeness down the pub... :hanged:
Perfectly ordinary two up/down, MK sentry split board, slightly dodgy rewire done a while back by another that I've already done a load of fixing on and a full (100%) periodic and thought had resolved all issues.
They have four dimplex panel convector heaters wired as two pairs, each pair off a B16 on same side of board. RCD on that side of the board intermittently trips when heaters on. Inspect heaters, test, no fault found. Replace RCD, no change. Chase my tail for a day, eventually find additional fault on an immersion circuit the same side of the board, resolve, problem seems to go away. Fast wind four months later to the cold autumn returning and I've just returned from a call-back, same fault.
I've checked and re-checked all the installation wiring - no insulation faults, no crossed neutrals, no naughty earths, no nothing (anymore). Have long-leaded from every joint to every joint on those two circuits. IR checked the fsu's, all 100% ok even at 1kV.
Have had my power analyser running on it all day, nothing unusual and heaters not particularly earth leaky (digital controllers, probably). Certainly would pass the normal PAT criteria.
RCD time & ramp tests all perfectly normal, and certainly well above the leak level of the heaters.
Ring dimplex helpline to see if they have a preference for 'S' types or something, discover chocolate fireguard at the other end.
One of them shows itself as being erratic on current draw as the thermostat is approaching close, and customer advises it was a 2nd hand buy, So I figure has to be that, remove, RCD stays set.
Pack up...... and RCD goes again. So scratching my head I do the only other thing I can think of and swap one of the circuits across to the other side of the board so it's on the other RCD.
Set the controls to stun, watch the numbers on the clamp meter go very high once I've turned on virtually everything on every circuit including the cooker and power-shower and leave for 20 mins to see what happens. Drink tea, cross fingers, all holds fine.
Pack up....... and......you guessed it.......
Putting RCBO's in aside, anyone got any ideas at all??
Perfectly ordinary two up/down, MK sentry split board, slightly dodgy rewire done a while back by another that I've already done a load of fixing on and a full (100%) periodic and thought had resolved all issues.
They have four dimplex panel convector heaters wired as two pairs, each pair off a B16 on same side of board. RCD on that side of the board intermittently trips when heaters on. Inspect heaters, test, no fault found. Replace RCD, no change. Chase my tail for a day, eventually find additional fault on an immersion circuit the same side of the board, resolve, problem seems to go away. Fast wind four months later to the cold autumn returning and I've just returned from a call-back, same fault.
I've checked and re-checked all the installation wiring - no insulation faults, no crossed neutrals, no naughty earths, no nothing (anymore). Have long-leaded from every joint to every joint on those two circuits. IR checked the fsu's, all 100% ok even at 1kV.
Have had my power analyser running on it all day, nothing unusual and heaters not particularly earth leaky (digital controllers, probably). Certainly would pass the normal PAT criteria.
RCD time & ramp tests all perfectly normal, and certainly well above the leak level of the heaters.
Ring dimplex helpline to see if they have a preference for 'S' types or something, discover chocolate fireguard at the other end.
One of them shows itself as being erratic on current draw as the thermostat is approaching close, and customer advises it was a 2nd hand buy, So I figure has to be that, remove, RCD stays set.
Pack up...... and RCD goes again. So scratching my head I do the only other thing I can think of and swap one of the circuits across to the other side of the board so it's on the other RCD.
Set the controls to stun, watch the numbers on the clamp meter go very high once I've turned on virtually everything on every circuit including the cooker and power-shower and leave for 20 mins to see what happens. Drink tea, cross fingers, all holds fine.
Pack up....... and......you guessed it.......
Putting RCBO's in aside, anyone got any ideas at all??
