Extractor Hood Tripping Rcd

[Malcolm]

Hi all.
When to a job this moring RCD had tripped, narrowed it down to the kitchen sockets, but found that the RCD stayed on for about 20-30 seconds before tipping out. Unplugged everything, so I thought.
Tested the RCD 1x 37ms - 36ms. 5x 11ms - 13ms. Ramp test 19.6 mA.
Then I realised the extractor hood was plugged in. Unplugged it RCD stayed on.
I then plugged it back in and switched it on, everything worked on it so as I was switching it off the RCD tripped.
So I measured the earth leakage on the hood as soon as I plugged it in . it started off about 2mA then slowly increased upto 20mA when the RCD knocked off. This happened even though the hood was not actually working.
Has anyone come across this before?
Thanks

 

[Pete999]

Hi all.
When to a job this moring RCD had tripped, narrowed it down to the kitchen sockets, but found that the RCD stayed on for about 20-30 seconds before tipping out. Unplugged everything, so I thought.
Tested the RCD 1x 37ms - 36ms. 5x 11ms - 13ms. Ramp test 19.6 mA.
Then I realised the extractor hood was plugged in. Unplugged it RCD stayed on.
I then plugged it back in and switched it on, everything worked on it so as I was switching it off the RCD tripped.
So I measured the earth leakage on the hood as soon as I plugged it in . it started off about 2mA then slowly increased upto 20mA when the RCD knocked off. This happened even though the hood was not actually working.
Has anyone come across this before?
Thanks

Have you carried out any tests on the Hood itself IR for example?

 

[Malcolm]

No. This was a job I wasn't expecting this morning. I was at another when a neighbour asked me to have a look. after finding this I just told her she needed a new hood.

 

[Pete999]

IR test the Hood as a matter of urgency could be the reason for RCD tripping

 

[Malcolm]

The hood is disconnected and she knows not to use it. She is also happy to have a new hood fitted, I just couldn't work out why the mA's would increase especially when it is not even switched on.

 

[Pete999]

The hood is disconnected and she knows not to use it. She is also happy to have a new hood fitted, I just couldn't work out why the mA's would increase especially when it is not even switched on.

Fan getting warm expanding shorting out somewhere, lectric is a funny fing you know, did you get the job of supplying a new Hood?

 

[Malcolm]

I wondered if something on the circuit board might have been causing it?
I told her to get someone to fit, but she said that she wants me to do it. So she is going to have to wait though, too busy at the moment.

 

[Pete999]

I wondered if something on the circuit board might have been causing it?
I told her to get someone to fit, but she said that she wants me to do it. So she is going to have to wait though, too busy at the moment.

Well it's not a matter of life or death is it/ cooker hoods my old mum just opened the window bless her.

 

[Wilko]

Hi M, I agree with Pete - an ir problem. It maybe in the switch wiring area as some hoods have the sw on the underside close enough to the extracted air flow to get a good greasing over time. If so, it may respond a bit of circuit degreaser/contact cleaner spray (Screwfix 92716). Cheers David.