Possible failed RCD

[trenelly]

Hi,

I would have thought it unusual for an RCD to fail? However, I have come across a Wylex WRS80/2 which gives >400ms reading for the 1X RCD test using a Megger 1552MFT. A no trip fail.

Could there be some other reason for this result?

Any help appreciated.

Regards,
Trenelly

 

[Simonslimline]

where are you testing the RCD?

Test should be carried out at the RCD with all loads dissed.

 

[trenelly]

It's protecting various circuits. My test was at a socket outlet.

 

[Pete999]

where are you testing the RCD?

Test should be carried out at the RCD with all loads dissed.

What he said

 

[Simonslimline]

It's protecting various circuits. My test was at a socket outlet.

Carry out the test as i described in my last reply and let us know how you get on.

 

[trenelly]

Will do.

Many thanks for your help.

 

[Deleted member 9648]

It's protecting various circuits. My test was at a socket outlet.

The problem is usually a load with a capacitor still connected, such as a fridge or fluorescent light. The capacitor holds a charge for a period after power is disconnected and fools the meter into continuing to record voltage after the RCD has disconnected the supply.
As above, test the RCD with all loads disconnected.

 

[trenelly]

Thanks for that explanation. I understand now.

 

[trenelly]

Did the test as you suggested - all good!

Mony thanks

 

[Simonslimline]

Did the test as you suggested - all good!

Mony thanks

Good stuff, everyday is a school day and all that. Good on you for letting us know.