RCD tripping with all 32amp mcb's turned off?

[benden]

Dear nice helpful Sparks and clever people,
would I be right in saying that if I turned off all the 32's on a newly installed board with a seperate RCD that it would trip the RCD after about 15 seconds due to maybe only half the normal current going through it??
Thanks and regards...Ben

 

[Steve]

do you have any idea what you are talking about? 32's?? why would turning off MCBs trip an RCD? You do realise that whether there is 80 amps or 0.1 amps flowing thru an RCD, it is only the current imbalance between phase and neutral that it cares about.

And you do also realise, dont you, that just because a circuit is rated at 32 amps, it doesn't nessecarily pull 32amps all the time . . .

and an RCD responds within a fraction of a second should an appropriate fault occur, not 15 seconds .

why are you asking this question anyway?

 

[1974stephen]

no, you wouldn't be right

 

[benden]

Hello Big Guys,
with regard to previous post of RCD tripping with 32's turned off was just wunderin whether it would be due to RCD tripping because of continous current of half their rated trip current going through it (ie 15mA on a 30mA RCD) this ensuring compliance with required "speed of trip" under human touch faults(whatever that means). And no I have no clue what I'm talking about - just asking for an informed opinion from people much cleverer than me.
Thanks...Ben

 

[andy]

Hello Big Guys,
with regard to previous post of RCD tripping with 32's turned off was just wunderin whether it would be due to RCD tripping because of continous current of half their rated trip current going through it (ie 15mA on a 30mA RCD) this ensuring compliance with required "speed of trip" under human touch faults(whatever that means). And no I have no clue what I'm talking about - just asking for an informed opinion from people much cleverer than me.
Thanks...Ben

and RCD should never trip at 15mA. and why would it trip when turnin MCB's off?

 

[JohnD]

Loosely speaking, an RCD will trip if you have a fault that leaks to earth. Are you saying that your RCD is tripping? Then you have a fault.

Are you saying that it still trips if you switch off all your MCBs? Then you still have a fault.

Does it still trip if you UNPLUG your kettle; washing machine; dishwasher; lawnmower; extension cable to the shed and any other "watery" or "outdoor" or "old" or "home repaired" appliances and cables? Then you still have a fault and you are probably not going to be able to trace it yourself (and perhaps you are lucky that the RCD has helped protect you so far).

 

[sparxfly]

15 secs to trip out as well....................... lucky devil mine takes 15 days

 

[pdcelec]

Dear nice helpful Sparks and clever people,
would I be right in saying that if I turned off all the 32's on a newly installed board with a seperate RCD that it would trip the RCD after about 15 seconds due to maybe only half the normal current going through it??
Thanks and regards...Ben

Call a professional, you do not want to risk the life of yourself and your family. Alternatively, call the people who installed it recently for their opinion. You will have a warranty on something that new.