Strange RCD Fault

[Guest569]

80amp main switch RCD, occasionally trips when a couple of circuits are switched on (doesn't matter which circuits) with nothing plugged in.

IR tests all good. Replaced RCD for new. Happens in all weather ( don't think its external )

Only sockets on this consumer unit.

Ive had my guys out at it twice with no joy. New build wiring from 16th edition.

Im going to investigate myself this week, Im sure Ive had loose connections causing tripping before, it about all I can think of, a loose tail somewhere around the main switch.


Anything else to look out for ?

Im pretty certain its not a dodgy nail at floorboard etc its fairly new property and in good condition with chipboard throughout.

 

[micknew]

Turns out boys only IRd at 250v.

I was round today but forgot bloody test gear...However I think I may have isolated the problem to some garden socket etc...holding so far, going back on fri with test gear.

Cheers for help

Best not send boys then.

 

[Guest569]

Best not send boys then.

In fairness they were concerned that everything was not unplugged ...didnt tell me tat yesterday though !

 

[GLENNSPARK]

Turns out boys only IRd at 250v.

I was round today but forgot bloody test gear...However I think I may have isolated the problem to some garden socket etc...holding so far, going back on fri with test gear.

Cheers for help

and?

whats nominals in the UK fella?

and what could you expect (single phase) off peak....roundabouts?

 

[Geordie Spark]

Turns out boys only IRd at 250v.

I was round today but forgot bloody test gear...However I think I may have isolated the problem to some garden socket etc...holding so far, going back on fri with test gear.

Cheers for help

Never send a boy to do a man's work. Look what happened when Cameron got into number 10.

 

[Guest569]

Tripped again !

Back on friday to test at 500V and 1000V.

 

[dazza1981]

80amp main switch RCD, occasionally trips when a couple of circuits are switched on (doesn't matter which circuits) with nothing plugged in.

IR tests all good. Replaced RCD for new. Happens in all weather ( don't think its external )

Only sockets on this consumer unit.

Ive had my guys out at it twice with no joy. New build wiring from 16th edition.

Im going to investigate myself this week, Im sure Ive had loose connections causing tripping before, it about all I can think of, a loose tail somewhere around the main switch.


Anything else to look out for ?

Im pretty certain its not a dodgy nail at floorboard etc its fairly new property and in good condition with chipboard throughout.

Ok lets have it right here.
You sent the BOYS out to look at this job twice now to look at why an rcd is tripping and they have not found the fault, how many boys does it take to look at why a rcd is tripping and some basic fault finding??
You then { presumably the boss} turn up for a third visit to the customer with no test gear and guess at it being an outside socket which it turns out it wasnt??
And the customer is happy for you to go back for a fourth time to have another go at it or are you sending the BOYS again??
What im getting at is i would be bloody embarassed to keep showing my face to these people who have the fault and quite surprised they aint got a sparks in to find the fault once and for all.
Poor sods power keeps tripping still after 3 visits by numerous so called sparkies!!
Perhaps you need to employ some new BOYS mate

 

[Guest569]

Ok lets have it right here.
You sent the BOYS out to look at this job twice now to look at why an rcd is tripping and they have not found the fault, how many boys does it take to look at why a rcd is tripping and some some basic fault finding??
You then { presumably the boss} turn up for a third visit to the customer with no test gear and guess at it being an outside socket which it turns out it wasnt??
And the customer is happy for you to go back for a fourth time to have another go at it or are you sending the BOYS again??
What im getting at is i would be bloody embarassed to keep showing my face to these people who have the fault and quite surprised they aint got a sparks in to find the fault once and for all.
Poor sods power keeps tripping still after 3 visits by numerous so called sparkies!!
Perhaps you need to employ some new BOYS mate

I don't need your opinion on my customer relations thanks pal.

Im not sure how much experience you have in the trade but...you should know faults aren't always clear cut and your certainly in no position to determine how easy this "should" be to solve from the other end of the country.

This one would leave plenty folk scratching their heads I think....Tripping under No load, new RCD, no loose connections, almost new cables throughout, IR good at 250v, no set circuit tripping, various circuits tripping it every few days for no reason. Holds with 3/4 circuits on. Sometimes holds with all circuits on for days.

The guy hasn't moved into the property yet. Its empty. Its also got 6 showers, around 10 bedrooms , 3 lounges, 2 dining rooms, 2 kitchens etc etc ...and around 25 circuits in total. We have done some work in the house but fault was happening before we started.


Hardly "basic fault finding"...so please stop with assumptions


Should also add the boys have been reluctant to take any risks on the job at 1000v or ripping walls etc and quite rightly so ...its a very expensive property.


Got to love this forum.......half the folk who comment would be lost on site but behind the computer - experts !

 

[High Tower]

Not a Crabtree board is it?, do you own a earth leakage clamp meter?

 

[Guest569]

Not a Crabtree board is it?, do you own a earth leakage clamp meter?

No its GE , are you thinking about the boards that got recalled ?

Could get earth leakage meter tomorrow...

 

[telectrix]

an earth leakage meter and a ramp test would be my option. ramp it with no circiuts. then 1 circuit, then 2 until the tripping mA drops. that might lead to the faulty circuit.

 

[High Tower]

No its GE , are you thinking about the boards that got recalled ?

Could get earth leakage meter tomorrow...

No I had a spate of Crabtree RCD's fail a couple of years back.

Have you even tried timing it?

You need to ramp it, and if it ramps out around 27 it's all good!

El clamp round the tails and check 1 circuit at a time with the rest turned off

 

[ipf]

.......... but often miss.

Subliminal....maybe...hehe.

 

[Guest569]

an earth leakage meter and a ramp test would be my option. ramp it with no circiuts. then 1 circuit, then 2 until the tripping mA drops. that might lead to the faulty circuit.

Yeah but fault seems to be intermittent which complicates things further....It SHOULD show at 1000V IR if the fault is always there right ?

 

[telectrix]

i'd be careful with a 1000V test. always the possibility of something left connected that you may not have seen, like aerial amp in loft.

just a thought..... if, as you say, the property is empty, is there a possibility of damp?

 

[ipf]

Yeah but fault seems to be intermittent which complicates things further....It SHOULD show at 1000V IR if the fault is always there right ?

It might be riding on the edge, it all adds up, after all........leakage tester's the way.