D
dannyv
Can anyone tell me how low the Ir value would be n/e for a rcd not to hold in! Would like to know as I always get problems prior to changing fuseboards
D
Deleted member 9648
Irrelevant really.....if it's under 1mohm you will have to sort it.
ohms law. 7.6kohms or 0.0076Mohms.
this is assuming that the voltage is 230v and that the RCD will trip at exactly 30ma.
Both of the above statements cannot be guaranteed
Edit: i totally agree with wirepuller, if i gets anywhere near 1Mohm, then invesitgate further.
this is assuming that the voltage is 230v and that the RCD will trip at exactly 30ma.
Both of the above statements cannot be guaranteed
Edit: i totally agree with wirepuller, if i gets anywhere near 1Mohm, then invesitgate further.
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D
Deleted member 9648
The voltage on the Neutral will be around 0v I think you will find
smartarse! lol
It would depend completely on the sensitivity of the device.
As wirepuller says, it is irrelevant as BS7671 2008 states >1Mohm, although (in the words of Tony Cable) that is simply an exam question and anything near that would require investigation. The answer would definately not be an IR value, and would be more of a low reading ohmeter value.
As wirepuller says, it is irrelevant as BS7671 2008 states >1Mohm, although (in the words of Tony Cable) that is simply an exam question and anything near that would require investigation. The answer would definately not be an IR value, and would be more of a low reading ohmeter value.
D
dannyv
What's the best quickest test to do on a fuseboard change survey to see if you ll get rcd trip problems neutral to earth across the whole install ?
Stick a earth leakage clamp meter around the tails and this will give you a start.
High leakage try taking the fuses out one at a time but this only gives you live earth leakage as the neutrals are all in one bar. So if high leakage still there taking neutrals out one at a time to find cct but this if hassel on a tight 3036 board or any board crammed with cable.
Make sure loads are disconnected unplugg in case of faulty appliance.
High leakage try taking the fuses out one at a time but this only gives you live earth leakage as the neutrals are all in one bar. So if high leakage still there taking neutrals out one at a time to find cct but this if hassel on a tight 3036 board or any board crammed with cable.
Make sure loads are disconnected unplugg in case of faulty appliance.
S
Sintra
Method 2 IR test.
D
Deleted member 9648
There's only one way...do an IR test.... anything under 1mohm will need investigation.
Also check for borrowed neutrals...most likely on the landing light of a 60's built house.
Also check for borrowed neutrals...most likely on the landing light of a 60's built house.
D
Deleted member 9648
...........
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