Intermittent Tripping

[skypie5]

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Supply trips at the main switch, but only after a prolonged dry period. As soon as substantial rain falls, supply remains connected with no tripping. Any help or suggestions as to why this may be occurring? Thanks

 

[mdshunk]

Sounds like it's time to break out the megger and find your insulation fault. Sounds like a textbook case of insulation leakage when it rains.

 

[skypie5]

Yeah, that was on my do do list. I am just perplexed as to why it does not trip after rain, but only trips when everything is dry !!!

 

[mdshunk]

Yeah, that was on my do do list. I am just perplexed as to why it does not trip after rain, but only trips when everything is dry !!!

That might just be one of those mysteries of electricity.

Seriously, it could be as simple as it might take a while after it stops raining for the rain to "soak in" to where the fault is. I've learned over time that sometimes when the facts don't add up, maybe the facts are wrong. It may have nothing to do with the rain and dry spells, but you only coincidently get the problem when it happens to have been dry for a while. Small matter, anyhow. The megger will get you sorted in a hurry. Post back when you find the fault. It will be interesting to learn what it was.

 

[skypie5]

Could this be an earthing problem, continuity when it is wet, and no continuity when it is dry? I cannot see or find any earth rod anywhere surrounding the house. The idea being to find the rod, clean the clamp and change if necessary.

 

[andy pandy]

check any outside lights first then the upstairs lighting circuit incase the roof is leaking.