- Joined
- 19 Jan 2005
- Messages
- 1,171
- Reaction score
- 41
- Country
OK peeps - here's one for you! This week I was working with my boss, upgrading the board and doing a rewire - but not the kitchen as the client didn't want 'disturbance'.
First step was to test out the existing installation - which we did and it was all tickety boo. Kitchen tested out as a ring.
However, when we connected up the new board, the RCD kept tripping on the kitchen circuit. Further investigation lead us to think that the kitchen was not a ring, but semi ring, JB and spurs. (Didn't ever find it - must have been buried in the wall!)
Two questions
1. If all the spurs out of the JB were of a similar length, would this give you the R1 plus R2/4 readings indicative of a ring (ie all vvv similar?)
2. Why did the RCD trip when it all tested out OK? We could only assume the JB was responsible for this, but surely the Insulation Resistance or Continiuty Tests would have thrown something up?
Anyway, we ended up putting in a new ring - the customer was a bit cheesed off, but had no choice.
Hope someone can shed some light on this, as I'm baffled!
Cheers
SB
First step was to test out the existing installation - which we did and it was all tickety boo. Kitchen tested out as a ring.
However, when we connected up the new board, the RCD kept tripping on the kitchen circuit. Further investigation lead us to think that the kitchen was not a ring, but semi ring, JB and spurs. (Didn't ever find it - must have been buried in the wall!)
Two questions
1. If all the spurs out of the JB were of a similar length, would this give you the R1 plus R2/4 readings indicative of a ring (ie all vvv similar?)
2. Why did the RCD trip when it all tested out OK? We could only assume the JB was responsible for this, but surely the Insulation Resistance or Continiuty Tests would have thrown something up?
Anyway, we ended up putting in a new ring - the customer was a bit cheesed off, but had no choice.
Hope someone can shed some light on this, as I'm baffled!
Cheers
SB