RCD won't trip

[shovelhead]

Hi
can anyone help.

I have just done an extension to an annexe, using 3 core 1.5mm swa for the lighting and 4 core 2.5mm for the ring into a 2 way CED Garage Consumer Unit with a 63A 30mA RCD, 32A and 6A MCBs.

Ze, Insulation resistance and continuity test came out fine testing with a Megger MFT 1553 but the RCD will only trip at 5x.

Any advice please?

 

[Hawk81]

Have you done a ramp test?

 

[shovelhead]

Yes, did a ramp test, that didn't trip.

 

[Geoffsd]

Could just be faulty. Have you another one you could put in?

Does it trip using the test button?

 

[Hawk81]

Sounds like a faulty RCD.

 

[young4r]

I accidently did an insulation test through a RCD once . it won't trip afterwards >Do-oh

 

[shovelhead]

The test button worked fine. I'll try changing the RCD and see if that improves things.

 

[telectrix]

first try testing at the RCD, loads isolated.

 

[shovelhead]

I'm not sure how to do that - can you expand? Thanks.

 

[Hawk81]

Switch off the circuit breakers and test at the RCD on the load side of the RCD.

 

[rob121]

Ill have a guess, remove bus bar and do a three lead test on the load side terminal screws and see if it trips. This means your rule out any possibility of it being down to the circuit(s) your testing. Coreect me if im wrong though

 

[rob121]

Was beaten to it, and with an easier way of doing it. DAM YOU! lol:53:

 

[Hawk81]

Ill have a guess, remove bus bar and do a three lead test on the load side terminal screws and see if it trips. This means your rule out any possibility of it being down to the circuit(s) your testing. Coreect me if im wrong though

No need to remove busbar. Switching off circuit breakers will do.

 

[shovelhead]

OK Will do, thanks

 

[shovelhead]

Tried testing the RCD on its own, replaced the RCD - it still won't trip.

 

[sparkinlee]

Long shot, but have you got you tester set on the 30mA RCD setting?

 

[vernam616]

What sort of make is "CED" ive seen a few CU's but never heard of this, does it have BS markings?

 

[topquark]

Yes, they have BS markings, not what I'd call a good make though. It's cheap and available from toolstation:

 

[shovelhead]

Could be - Now you mention it I didn't double check - I'll give it another go tomorrow.

 

[Des 56]

What sort of make is "CED" ive seen a few CU's but never heard of this, does it have BS markings?

I may be wrong but I believek CED stands for Countrywide Electruical Distributors,they import foreign junk and sell it on with their own marking on them