unusual electrical faults

[Pete999]

Went with Camerabloke to look at a faulty alarm the other day, door opens come in the box is in there, so he proceeds to pick up all the clutter in the cupboard, bung it on the Kitchen floor, Camerabloke does the biz and matey chucks all the stuff back in the cupboard, some people?

 

[camerabloke]

And on the return visit was the same. Even though time and date was agreed I still had to wait while it was cleared

 

[dingledong]

Get that lots yes I need to get to your fuse board or immersion, turn up on the day and you have an hour of cleaning the cupboard out

 

[NDG Elecs]

Had one that took around a month to solve, with approx 6 visits in total. RCD was tripping intermittently only on hot and sunny days and in the late afternoon only. Straight away I was thinking WTF! Long story short it turned out to be a cable to an outside light that went through the wall between the brick and a dark coloured uPVC door/window frame. The frame was heating up and expanding just enough to slightly crush the cable. Only found it after the umpteenth visit and the customer mentioning their uPVC door did not open at all after a hot sunny day, which made me think was this related.

I hate intermittent faults - PITA usually.

 

[Tiny Spark]

Strangest one I was ever involved with went something like this:

Company had shut down for a week so we had all the HV testing done, After the testing and all the HV was back up and running my then boss was turning all the LV sub main breakers back on when one blew up when he turned it on!
Give him a nasty burn on his arm and the air turned blue.
So anyways contractor was called to test it and replace which they did, IR testing clear and breaker replaced turned on and it trips instantly (luckily no boom this time).
So they re-checked everything again and said it was ok and couldnt understand it.
So My gaffa concludes this is BS and wants a second opinion so sends us in to break the circuit down and test.

This perticular breaker fed a sub main board which had the breakers for 2 DB's and 2 Lifts which were all isolated so we knew the fault was between the sub station and the sub board.

So we stripped the sub board down to basics, IR tested the bus bars etc etc and found nothing!

I ring the gaffa and tell him its all clear and we found nothing, He shouts and swears at me that there has to be somthing (which I agree) But nether the less there is nothing.

By this time we are all getting a bit ****ed with this thing so in a bit of a temper I smack the side of the board and low and behold a 32mm metal hole saw cut out bounces onto the floor and you would never guess it was all black and crispy!

I have no idea how it didnt show up on the IR tests or where it was actually hidden, I can only assume the second time the circuit was energised it had blown off to a location undisclosed until I smacked the board one!

But after putting everything back together and turning the breakers back on everything was fine and dandy again