Crabtree Starbreaker RCBO not tripping

[Pip]

Hi People,

Just fitted a Crabtree Starbreaker 40 ma RCBO for a new shower circuit. Problem is it won't Trip at the test button on the unit, Why?

Followed all fitting instructions, Load 'N' to outgoing and Load 'L' to outgoing terminal on breaker.
Incoming 'N' flying lead to Neutral Bus bar.
Functional 'E' flying lead to Earth terminal in CU.

This breaker is fitted before any other RCD;s in the consumer unit, (of which there is 1) so not expecting any imbalance problems.

R1 & R2 and IR test on shower circuit all good.

Power was off for the day when I fitted the unit, so could not RCD test at the time, went back to day to test and went no further when the test button did not operate.

This led me to check my connections and I'm still happy with them, in fact the shower works fine, but I'm concerned that it does not trip out

What do we think?

 

[nickblake]

that sounds to me like a faulty RCBO , it should trip when the button is pressed

 

[Sintra]

You say there is already an RCD fitted in the cu. Are you 100% sure that you have your neutral flylead connected to the main neutral bar at the cu and not the neutral bar belonging to the original RCD.

 

[Pip]

Hi Sintra, I'm 99.9% certain that it's connected to main neatral bar, as I've fallen for that one before, so checked it again today and the main neutral lead from the main switch goes to this bar, and the neutral from the RCD goes to a second bus bar.
Pip

 

[Deleted member 9648]

A functional check is essential as well as a test...sounds like a duff'n to me.

 

[Sintra]

Hi Sintra, I'm 99.9% certain that it's connected to main neatral bar, as I've fallen for that one before, so checked it again today and the main neutral lead from the main switch goes to this bar, and the neutral from the RCD goes to a second bus bar.
Pip

Well in that case i think you need to replace the RCBO.

 

[tony mc]

If its fitted correct and will not trip on the test button take it back and replace it as it needs to be tested at least quartelyand trip when tested.

Just out of interest does it trip at 1x and 5 x when you test it on your meter?

 

[Pip]

As I say, not RCD tested from my meter as I stopped when the test button did not operate, (and could not do it on the day of fitting.)
I'll go back and RCD test before I swap out and return RCBO, at the same time test the original RCD also.

 

[sparkswillfly]

Y bother. Get it replaced it need to let go on the button

 

[Pip]

Just a quick up date, Called Crabtree tech department, they agree it's duff RCBO, got a replacement from my wholesalers, replaced that today, and it does the same thing, does not trip from the test button, Called Crabtree tech, they were at a loss as to why, 1 is possible, 2 seems unheard of.

So refitted the original RCBO, and thought may as well do the RCD test, and low and behold, it works, x 1 test (0 degrees 18.1ms) (180 degrees 17.8ms). x 5 test (0 degrees 7.9ms) (180 degrees 18.2ms)

I got my numbers, but still will not trip on the test button, so where do we go from here when it comes to Minor Works Cert?

 

[RogertheBodger]

Bad batch at your wholesalers maybe?

 

[Pip]

Just to update and end this thread, after speaking to Crabtree for a second time, re second breaker not tripping, they could not help.
My wholesaler insisted I have a third RCBO, so fitted third RCBO, and surprise surprise it now works as it should, so as you say Roger, a bad batch by the looks of it. No help from Crabtree.
Thanks all for your input

 

[SPARTYKUS]

To be honest doesnt suprise me. Off all makes have had most problems with crabtree over past three years. Which is a shame as they are (still ) considered 'up there' as a good make.