Testing RCD,s using 3 leads or 2?

[jamesBoater]

When testing an RCD/RCBO is it proper procedure to have test leads on line neutral and cpc? or is a 2 lead line and cpc test ok?

basic question i am sure but just want to make sure i am doing things properly.

thanks james

 

[growler]

u need 2 leads to test rcds

 

[jamesBoater]

Thanks for the reply, i ask as i have previously tested only using 2 leads (line + cpc) and trip times seemed good and all tests worked? i was told by a (Qualified) spark that 2 leads was ok? however have read elsewhere that this may not be the case?

 

[brizospark]

The megger mft I use only requires line and earth to test rcd trip times and ramp test

 

[jamesBoater]

we use a megger 1552 and a 1730, i was using 2 leads with both these testers.

 

[jaydee81]

two leads is the norm at least it is on megger 1552

 

[jaydee81]

check megger instruction booklets is two leads or switch probe and one lead

 

[paul_h]

It usually depends on the meter I think?

 

[jamesBoater]

so i suppose it varies due to what tester you may be using then!.

Edit... beat me to it

 

[telectrix]

yep. if your'e using wet fingers, 2 fingers will do.