Lights flickering during the rain???

[Cigaro]

Hi all,

Got another brainteaser for you all.

Ever since we moved into this house the lights have flickered slightly, seeming to get worse when it's raining heavily outside.

All circuits are affected - lighting and sockets.

Last night they were flickering pretty badly, so I decided to investigate. I know this sort of problem is usually caused by a loose connection, so I thought I'd check that first.

I have taken the cover off the consumer unit - all connections in there are tight. Waggling the meter tails makes no difference - the flickering does not happen more, or stop, when I do this.

No heat, no signs of arcing.

So, I'm pretty sure the problem is on the supplier's side. Is there anything else I should check before calling them to take a look? Will they look at something so trivial as flickering lights, as there isn't any sign of any immediate danger inside the house?

Anyone ever seen anything like this before? Surely it's quite rare for this sort of problem to be on the supplier's side? Could it be water getting in an underground cable joint or something?

 

[Space cat]

If you haven't done it already, I would look in the loft (if any) to see if rainwater is dribbling into any junction boxes up there. Then I'd go all round the outside of the house looking for any external lights or sockets or any signs that wiring has been there. My parents' house once had a switch by the garage gate for an outside light. The light was gone but the switch was still there - and still live! They only found out when a fuse started to pop when it rained.

Here's another idea. Next time you get that flickering, turn off breakers (or pull fuses) in the CU one at a time and see if the flickering stops. If it does, you'll have narrowed the problem down a lot.

 

[Cigaro]

Ah, so you're thinking that it may actually be a low-grade short causing it from rainwater getting into something, rather than a loose connection. Good thinking

I'll do that tonight - try turning off various circuits to see if I can get it to stop. I do have outside lights so I suppose they could be at fault.

Cheers.

 

[radioredcat]

A fault on the HV side can cause this effect as we have had this here but if i were you i would ask the neighbours especially next door but 2 (every third house from yours) if they are having similar problems.

Of course as said you need to check your installation.

Andy

 

[xr4x4]

Do you have a rcd?

 

[Cigaro]

Radioredcat> I'll check, thanks. Of course naturally they haven't flickered all night tonight

Xr4X4> No RCD.

 

[xr4x4]

Ok, so you could have water in your electrics and not know it.

 

[Cigaro]

Sounds like I'll have to go round the whole house checking sockets and junction boxes (some of them are ba*tards to get to) on Saturday, then.

Idea - I may see if I can lay hands on a megger. Take it this sort of fault may well show up with IR testing?

 

[xr4x4]

Yup.