Time delayed RCD

[Carlosfandango]

My guys were testing a 500ma time delayed RCD today with our Fluke tester, can’t remember the model, 1556???
I had a go and couldn’t get it to trip either. The tester was set to time delayed setting, 500mA, did the 30s countdown but didn’t trip. Am I doing something wrong?? And yes I was definetly testing the load side of the RCD!?

 

[buzzlightyear]

the question how was you testing it ,with 3 probes or two ?

 

[Carlosfandango]

the question how was you testing it ,with 3 probes or two ?

Tried 2 and 3, no avail!
The RCD is a TP 100amp mccb, 2 years old so doubtful that it’s faulty.

 

[Risteard]

My guys were testing a 500ma time delayed RCD today with our Fluke tester, can’t remember the model, 1556???
I had a go and couldn’t get it to trip either. The tester was set to time delayed setting, 500mA, did the 30s countdown but didn’t trip. Am I doing something wrong?? And yes I was definetly testing the load side of the RCD!?

Had you it set to the correct type of RCD, i.e. you weren't DC saturating an AC RCD or something like that?

 

[Leesparkykent]

Try it on the circuit not at the terminals. I can’t remember but there was one or two brands that don’t like being tested at the terminals...I don’t know the reasoning behind it, but worth a try.

 

[westward10]

Did it have a 30s delay.

 

[davesparks]

Try it on the circuit not at the terminals. I can’t remember but there was one or two brands that don’t like being tested at the terminals...I don’t know the reasoning behind it, but worth a try.

It's memshield 2 MR30 RCBO pods which can't be tested from the terminal screws because the live sensing coil is on the pod which clips on above the terminal.

 

[Pete999]

Tried 2 and 3, no avail!
The RCD is a TP 100amp mccb, 2 years old so doubtful that it’s faulty.

Your 2nd sentence The RCD is a TP 100A mccb? don't compute, mind you it is early

 

[7upsgreat]

I had a similar issue with my Megger MFT Can't remember exactly what I was doing wrong but re read the manual and it worked.