RCD Fault.

[bigbaddave]

Right here goes,EICR report on a TT install, ZE 99 Oams. It global 58.6 meg. RCD test tho trip on x1 x5.ramp test no joy. Assumed faulty RCD change for new one again no trip.try a third one and no trip. Loop on the same socket 99.1 Oams. It's not faulty RCD as they work fine In another install. Anyone had the same issue

 

[Tim]

Try testing the rcd from the terminals with no load on the circuit.

 

[bigbaddave]

Done. No joy

 

[Outspoken]

Tester buggered by the sounds of that!!

 

[Plonker 3]

You tried testing the RCD with a length of cable attached to it so not directly testing on the terminals?

 

[Guitarist]

Tester buggered by the sounds of that!!

Have you confirmed that the tester is fine on another install?

 

[timbobelfast]

Check tester is on the correct parameter as I have had this blonde monent before.....

 

[DaveyD]

Check tester is on the correct parameter as I have had this blonde monent before.....

Yes, you mean if left on 30mA when testing a 100mA TD - Done that! :0

 

[bigbaddave]

Hi yes tester is fine, tried on a few installs. the funny thing is that there was a N-E fault on the install when i turned up. The RCD was holding. After finding the IR fault changed the RCD assuming that this was faulty but new new one still no joy and again the next one didnt trip.. So just to try and confirm put the N-CPC fault back on and the RCD held... Well it did for hour or so.. then tripped and couldnt be reset as you would expect with a N-CPC fault. Took the N-CPC fault off and retested. RCD tested ok.. Then 20 minutes later didnt test ok.. put the N-CPC fault on and again didnt trip.. At each stage of the testing a ZS reading was taken to ensure that there a reading.

The N-cpc confirms that its not the tester and the testing the 3x RCD'S in differant installs confirms its not the RCD

 

[DJ Ovengloves]

All MCB's off so there's no chance at all for any leakage to be already present?

Try testing the rcd from the terminals with no load on the circuit.

Done. No joy

 

[Plonker 3]

Sounds like you may have a crossed neutral which is intermittently being switched on and off maybe?

 

[richardg]

Sounds like you may have a crossed neutral which is intermittently being switched on and off maybe?

Good morning sorry if I'm sounding a bit slow, I've just woken up.
you mentioned this is a TT system! Is the RCD the main switch 100mA?

 

[bigbaddave]

Sounds like you may have a crossed neutral which is intermittently being switched on and off maybe?

Its not no, its a MAIN switch RCD and not a Duel board on this occasion im affraid

- - - Updated - - -

Good morning sorry if I'm sounding a bit slow, I've just woken up.
you mentioned this is a TT system! Is the RCD the main switch 100mA?

It is a TT however this one has a 30Ma as the main swicth and not a 100ma

 

[GJD]

They've not put a Time Delayed RCD on to allow discrimination have they? I've been stumped by that before!

 

[telectrix]

don't recall ever seeing a 30mA time delayed RCD.