Carbon Monoxide Alarm Fault.

[Declan Black]

Hi all
I'm a first year trainee and recently I went to test an existing installation at a property. Everything was testing out fine until we started to ZS the upstairs and downstairs lights. As soon as I hit the test button whichever lighting circuit I was testing tripped out. We then removed the carbon monoxide alarms and both circuits tested out fine. After this we changed the cable which fed the carbons from the lights and tried to test it again but it kept tripping. Our supervisor told us to remove the carbons completely and leave it.

I'm really curious as to why the carbons were making the lights trip when ZS'ing them...

Any explanation as to why this happened would be great and any suggestions as to how to fix the problem would be excellent.

Cheers

 

[shanky887614]

Hi all
I'm a first year trainee and recently I went to test an existing installation at a property. Everything was testing out fine until we started to ZS the upstairs and downstairs lights. As soon as I hit the test button whichever lighting circuit I was testing tripped out. We then removed the carbon monoxide alarms and both circuits tested out fine. After this we changed the cable which fed the carbons from the lights and tried to test it again but it kept tripping. Our supervisor told us to remove the carbons completely and leave it.

I'm really curious as to why the carbons were making the lights trip when ZS'ing them...

Any explanation as to why this happened would be great and any suggestions as to how to fix the problem would be excellent.

Cheers

ok what is the other name for a zs test?

what causes an rcd to trip?

electronics can leak to earth, just curious but what tester were you using and did you ramp test the circuit with carbon in situe? it might trip at 1/2

 

[LankyWill]

Hi all
I'm a first year trainee and recently I went to test an existing installation at a property. Everything was testing out fine until we started to ZS the upstairs and downstairs lights. As soon as I hit the test button whichever lighting circuit I was testing tripped out. We then removed the carbon monoxide alarms and both circuits tested out fine. After this we changed the cable which fed the carbons from the lights and tried to test it again but it kept tripping. Our supervisor told us to remove the carbons completely and leave it.

I'm really curious as to why the carbons were making the lights trip when ZS'ing them...

Any explanation as to why this happened would be great and any suggestions as to how to fix the problem would be excellent.

Cheers

This is quite common with accessories with pcbs fitted inside them. If its works fine with no load connected and your IR results were >299 then it should be fine. I had this once with a shower which turned out to be faulty. Take shankys advice and ramp test the rcd to check for over sensitivity.