Rcd fails test.

[jelly belly]

Hi, I've been installing a new shower, using a shower consumer unit complete with rcd. All the tests passed, r1 And r2 were 0.23 ohms, insulation resistance was >299M ohms, polarity was correct. But when I test the rcd I cannot get it to trip. It passes when the test button is pressed but will not pass the rcd test at 1 or 5 times, it fails to trip and my tester says time exceeded and shuts off.
Every thing appears correct I ran out of time so have isolated it the shower and will investigate it again tomorrow.

all advice would be appreciated.

thanks

 

[domn]

one thing to check is that you have not put your meter onto test a dc rcd i was having the same thing on a job took me bloody ages to realize.

dom

 

[Hawkmoon]

Onions, thanks for that, that was what I was thinking, i was beginning to think I had missed something. But as the r1 and r2 and insulation tests are ok there shouldn't be a damage to the cable. I checked all connections were tight in both the shower and the switch unit.

Zs test at shower would have confirmed your earth was good without the rechecking of all your connections (as you already done r1 & r2)

You said you checked the other RCD with the plug attachment - I would check both RCDs, at the board, with the leads - if one trips and the other doesn't then as Onions said......

 

[tony mc]

Hi, I've been installing a new shower, using a shower consumer unit complete with rcd. All the tests passed, r1 And r2 were 0.23 ohms, insulation resistance was >299M ohms, polarity was correct. But when I test the rcd I cannot get it to trip. It passes when the test button is pressed but will not pass the rcd test at 1 or 5 times, it fails to trip and my tester says time exceeded and shuts off.
Every thing appears correct I ran out of time so have isolated it the shower and will investigate it again tomorrow.

all advice would be appreciated.

thanks

You have not mentioned ZS! I take it your shower unit has a ZE /Ra ?

 

[jelly belly]

Ze is 0.13 and zs for shower is 0.38.

 

[jelly belly]

Hawk moon, I will try your suggestion tomorrow, I've got to prove rcd, either is duff or that there a fault elsewhere.
Thanks to everyone for all the advice, as always it's helpful.

 

[Guitarist]

Hawk moon, I will try your suggestion tomorrow, I've got to prove rcd, either is duff or that there a fault elsewhere.
Thanks to everyone for all the advice, as always it's helpful.

You mean what I suggested in post 9?

 

[Hawkmoon]

You mean what I suggested in post 9?

acknowledged - now I have read all the posts 'properly' - you did mention that in post 9