RCDs

stewart · Oct 20, 2010

Hi all,

I've tried searching but every time I hit the 'search' button, it takes me out of the forum!

Set up: 6-way consumer unit (changeover). 30mA rcd controlling 4 power (32+32+16+40) mcb's + 2 6a rcbo's for lighting.

I've done all the testing. Voltage 247v. Everything fine but....

Upon testing the RCD,it trips 10.2mA @ 1I, and 8.4mA @ 5I
And the rcbo's ... 18.2mA @ 1I and 18.1mA @ 5I

Can I have some help in understanding what's going on. I know it's the rcd/rcbo combination (cause I changed it all for a straight 6-way unit with ONE rcd and then the results were as expected I-30.2mA & 5I-6.9mA ...)

thanks,

Stewart

Darkwood · Oct 20, 2010

Are you sure your not mixing miliseconds up with mA your x1 and x5 are trip times not mA

stewart · Oct 20, 2010

darkwood said:
Are you sure your not mixing miliseconds up with mA your x1 and x5 are trip times not mA

LOL .... no doubt I am .... yes, milliseconds it be ..... the question still remains

m4tty · Oct 20, 2010

What's the question mate. Them rcd test results pass.

Darkwood · Oct 20, 2010

Im with m4tty here, i dont understand what question you are asking, you have shown us a set of results that have passed so what is the question, are you confused that the x5 results should be a fifth of the x1? this isnt the case and this rarely is the case, to pass it just has to trip within the specified times thats all, existing leakage, load, voltage etc will all play a small part as to the result but as long as they meet the regs then all is good.

stewart · Oct 21, 2010

Well there you are then, all safe and sound

Hmmm, yes I was confusing the mA with the mS lol ..... put it down to a hard day and refusing to think clearly! Shall just go off and write out 5,000 times - "I must not write in to forum when thinking like a plumber!" ..... 5,000 lines later...... sigh! that's better, I shall go and make myself a nice cup of tea