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?

 

[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

 

[vernam616]

Buy cheap = Buy twice

However in cases of electrical work it can be a big risk, i wont fit any electrical accessories unless they are BS marked and a reputable well known make, was once asked to fit a dimmer for someone and realised there was no BS marking, might sound pedantic but i left it, i wasnt putting my name on it

 

[timo1]

CED are pretty poor in my experience, I fit one that a customer bought brand new out the box one of the RCD's failed so had to get another and replace it took an hour out my day so have decided will never use them again. I personally use wylex with RCBO's haven't had a problem yet. In fact if I can I avoid dual RCD boards altogether now RCBO prices are fairly reasonable.

 

[shovelhead]

Thanks for the tip - I liked the look of the boards as it came with grommets for the leads - The last c/u I put in was a wylex and I found it really awkward nipping out the body to get the leads through.

 

[tony mc]

Did you get to the bottom of your RCD problem ?

 

[shovelhead]

I can't get in to the premisis till this evening, but I strongly suspect that I had the megger set on 30mA - That's the one thing I didn't check , obvious though it is, and I can't think what else it might be

 

[topquark]

That's what it should be set to, 30mA ... you said it was a 30mA rcd didn't you ????

 

[SPARTYKUS]

Buy cheap = Buy twice

However in cases of electrical work it can be a big risk, i wont fit any electrical accessories unless they are BS marked and a reputable well known make, was once asked to fit a dimmer for someone and realised there was no BS marking, might sound pedantic but i left it, i wasnt putting my name on it

I've tried all the top makes & aload of cheap ones over the years, and do you know what, the worst failure rates are .....wait for it......

CRABTREE

WYLEX


NOT chint, CED, ECD, tenby, etc etc

 

[shovelhead]

That's what it should be set to, 30mA ... you said it was a 30mA rcd didn't you ????

Sorry, I meant to say that I hadn't got the megger set to 30mA

 

[topquark]

Best hope you had it on 10mA then and not higher than 30mA, otherwise you are in trouble

 

[shovelhead]

I'll find out shortly....