What Denotes An Over Sensitive Rcd?

[Barx]

I've come across those 5 into 1 multi plugs where the neon power indicators were wired between L & E.

Sneaky little monkey. Well if it still nuisance tripping (they will be letting me know) then I will check every nook and cranny for an illusive neon. 1 suspicion of mine early on was an immersion but she had no idea if she even had one. And the airing cupboard was off bounds :facepalm:

Would have to wait for hubby to be home, he is working away... either way it would deffo be turned off.

 

[Steve3948]

Those 4 Way surge protected sockets can be problematic also, had a house where they had three and caused nuisance tripping, also a month or so ago had a house with just one which was causing RCD to trip.

 

[SPECIAL LOCATION]

as far as we are aware, everything was unplugged / disconnected. Would a neon cause earth leakage, surely they would only affect reading L - N not (L+N) - CPC

A neon will not normally trip an RCD, even if wired across L-E...

Although they will give an unrealistic low insulation resistance test reading...

With this sort of problem you have to stop and step back and think about exactly what you are reading and what is and ins not acceptable in the regs...

If all test readings are acceptable to the regs then the wiring will Not be causing any RCD trips..

and if the RCD tests are within the tolerance specified by the regs then the RCD will not be giving nuisance trips..

If trips continue to occur there is either a faulty appliance or group of faulty appliances..

Or a selection of equipment with natural leakage to earth that when combined can exceed the RCD tolerance..

Some ovens specifically state they should NOT be connected via an RCD do to some natural leakage..

Don't get mixed up with your numbers when testing...

Remember...  Page 191 table 61

Minimum Ins Res 1.0meg  or 1,000,000ohms    or  0.00023amp acceptable

RCD must not trip @ 15ma  or 0.015A  or   15333.33ohms should Not trip RCD..

RCD must trip @ 30ma or 0.03A  or  7666.66ohms MUST trip RCD.. 

The average Neon (go do an Ins Res across a lead with a neon socket attached) will give around

0.25Meg  or 250,000ohms    To  0.30Meg  or 300,000ohms

So these neons would show as a too low Ins res reading...  But are still to high for tripping an RCD.

Some of those illuminated light switches have neons wired from L to E.. (as no N @ switch)

Did you double check both ways on two-way light switching when doing your Ins Res tests?

My gut feeling is something involving water...

Central heating pumps valves etc..

Immersion heaters

Steam Irons

Washing machines / Dishwashers  (outlet pipes blocked causing back flow across electrics)

Cordless kettle bases

etc....

either way even if the RCD is operating all OK

as a single mains switch RCD the installation does not comply with  314 page 46!

 

[mole2006]

Also watch out for those plug in air fresheners, I've seen a couple of them have low IR readings and cause the rcd's to operate.

 

[Andy™]

Also watch out for those plug in air fresheners, I've seen a couple of them have low IR readings and cause the rcd's to operate.

every air freshner ive seen is class II with a plastic earth pin.... so maybe low IR L-N, but not L/N - E, and wont trip an RCD