Square D rcd wont trip with my tester

[magnoliafan89]

Hi guys wondering If anyone can shed some light either through knowledge or experience of the same problem.

I have a Megger MFT 1731. Whenever I come to square D type rcds my tester doesn't trip them. I try it on doing the manual settings for 1x and 5x and even the auto. Ramp tests won't either. I manually turn them off and and on a few times and test buttons use to make sure they haven't stuck or anything.

Yet when my colleague uses his rcd tester hes able to trip them.

No other type of rcd or robo gives me problems just this make.

Am I missing something or is it my tester?

 

[Charlie_]

You have got it set to continuity

Have you checked the rcd parameters are set correctly- AC?

 

[DT1991]

Are you staying it doesn't trip all Square D? Or just this one.

 

[Raeb]

Are you testing at the DB, or away from it? I have had problems with MEM RCBOs not tripping when tested at the DB but would when at a socket etc.

 

[freddo]

Are you testing at the DB, or away from it? I have had problems with MEM RCBOs not tripping when tested at the DB but would when at a socket etc.

That is because the Line terminal bypasses the tripping coil on the MEM pods. Caught me out the first time I tested one.

 

[magnoliafan89]

Testing both at the rcd and at a socket or light etc. No just i had a photo of that one spare but otherwise it's all sqaure d rcds

Its just odd that mine wont trip it yet when my colleague comes his can

 

[Bob Geldoff1234]

It's not maybe the internal difference between a old type RCCB and the new type RCD. It could be your meter doesn't like,or won't trip,the old style RCCB's?

 

[telectrix]

have you tried a ramp test with your meter?

 

[freddo]

It says he has in the first post.