- Reaction score
- 5,659
I have just popped out to a frustrated customer who has had intermittent tripping of a 30mA RCD for years, on average 5 - 10 x p/month. It used to be 10 x p/month a year ago, now it is around 5 times p/month. This is a dual RCD board (Harok??) with 2 socket circuits and 2 lighting circuits on the affected side. There is alot of electronic equipment plugged in.
I did a x5 and x1 test (at a socket). The RCD tripped but the tester just came up with 'trp' meaning it tripped too quickly for a reading. The ramp test did the same. I then tested at the RCD and it tested as 24mA and 19ms. The customer was adamant the RCD was 'too sensitive', but the above tests seem to show it is not (although 19ms is a little quick).
Global IR results showed 1.7Mohm N-E.
I clamped the Main earth (TNCS). It jumped up to 26mA for <1s and then stayed at around 3mA. It did this every time I tested. It is a poor quality earth clamp meter. He had switched off most of his electronic equipment when I tested, but not unplugged, therefore N still attached.
He just wants me to change the board, and throw money at me as he is so fed up. However, that's likely not going to solve the problem, hence having a chat with you guys.
Would an RCBO board help? I.e if it is a build up of earth leakage this option would help. It wouldn't help if all the earth leakage was just on one circuit though.
Do you think it is natural earth leakage from electronic equipment? If so, what is the solution? I'm not too sure how to test each item of equipment for earth leakage.
Perhaps it is something else. Is 19mS too quick to trip (I think it is on the low side, but not abnormally low)?
Perhaps an intermittent fault which didn't show up when I tested. However, he said it had tripped just before I came and tested.
My instinct is on accumulated earth leakage, but again I'm unsure of the solution or testing for this.
Cheers all ?
I did a x5 and x1 test (at a socket). The RCD tripped but the tester just came up with 'trp' meaning it tripped too quickly for a reading. The ramp test did the same. I then tested at the RCD and it tested as 24mA and 19ms. The customer was adamant the RCD was 'too sensitive', but the above tests seem to show it is not (although 19ms is a little quick).
Global IR results showed 1.7Mohm N-E.
I clamped the Main earth (TNCS). It jumped up to 26mA for <1s and then stayed at around 3mA. It did this every time I tested. It is a poor quality earth clamp meter. He had switched off most of his electronic equipment when I tested, but not unplugged, therefore N still attached.
He just wants me to change the board, and throw money at me as he is so fed up. However, that's likely not going to solve the problem, hence having a chat with you guys.
Would an RCBO board help? I.e if it is a build up of earth leakage this option would help. It wouldn't help if all the earth leakage was just on one circuit though.
Do you think it is natural earth leakage from electronic equipment? If so, what is the solution? I'm not too sure how to test each item of equipment for earth leakage.
Perhaps it is something else. Is 19mS too quick to trip (I think it is on the low side, but not abnormally low)?
Perhaps an intermittent fault which didn't show up when I tested. However, he said it had tripped just before I came and tested.
My instinct is on accumulated earth leakage, but again I'm unsure of the solution or testing for this.
Cheers all ?