What dangers may arise if you allow non-performing RCDs to remain in circuit?

[lofty84]

erm ....

any bright sparks about

 

[telectrix]

possible fatalities.

 

[Fender]

Non performing as in broken, not working?

 

[telectrix]

i assume he means not tripping.

 

[lofty84]

thanks guys, yes not working maybee faulty I guess. do you mean possible fatalities becasue of the 30ma it takes to kill a human or .........

 

[Dean]

Are you asking this question as an electrician that doesn't know? Or are you just looking for general answers?

 

[i=p/u]

the rcd not operating in designed times, possibly is allowing the earthed exposed and extraneous parts rise above 50v more than 30mA

 

[SirKit Breaker]

Not sure what you are trying to get at, sorry.

However i can explain why a 30mA RCD is rated at 30mA. It has been proved that in almost all cases a human being of any age can withstand a fault current of 30mA as this is not enough to stop your heart. But it is enough to cause your chest muscles to go into spasm and stop you breathing, It has a maximum disconnection time of 400ms, and most if not all people can hold their breath for more than 0.4 of a second, so that is why we fit 30mA RCD's with a maximum disconnection time of 400ms into final circuits.

Science lesson over for today.

Cheers..........Howard

 

[telectrix]

if it don't trip at all, a damn sight more than 30mA can flow through the human body. assuming aveage body resistance of 1kohm, well earthed, thats around 1/4 amp.

 

[lofty84]

Im almost qualified with just the 302 and 303 practicals left to go but along side this we have to do a NVQ and this was a question on one of the units

thanks a million for all the top top answers I was just double checking ......