RCD test

[smilie]

hello every one can some body help me please in this particular question?When tested at Idn time 5 , a 30nmA RCD protecting a 230 V a cooker circuit incorporating a socket outlet in its control unit must trip within : time please

 

[LeeH]

40ms 0.04s

 

[driverman]

Earthing system?

 

[Bobster]

Earthing system?

Why does that matter?

 

[Plonker 3]

Ooh look a homework question where the OP cant be bothered to do any research themselves.

 

[telectrix]

Why does that matter?

afaik, the disconnection time for a TT system is 200mS @ x1, but can't find anything in the regs for a x5 time on a TT. perhaps that's driverman's concern.

 

[driverman]

afaik, the disconnection time for a TT system is 200mS @ x1, but can't find anything in the regs for a x5 time on a TT. perhaps that's driverman's concern.

Yes ,that was my concern when first looked at it. Not sure about 5 times now.

 

[Richard Burns]

The testing of a 30mA RCD at 5 x IDn is only applicable to an RCD providing additional protection to persons and livestock and the requirement in that case is for the RCD to trip in less than 40ms. This would be independent of the earthing system as the trip time is not related to the maximum disconnection times required for disconnection in the case of a fault.

 

[Pete999]

Smilie
Bit of advice mate ask one of the mods for access to the trainee forum you will get more help, have you got a copy of the OSG? someone has mentioned this may be a homework question, the answer you are looking for, may be in the OSG page 105, you will get grief if you ask a question without researching it yourself, which in this case looks likely.

 

[smilie]

thank you all for the reply much appreciated