Time Delay RCD For A commercial premises

[Benyamin]

I have changed a new fuse board in a Shop with about 4 Fridges and i have got a problem with the RCD keep tripping and I put 100ma time delay RCD instead of the 30ma and the RCD Tripped few times and then stopped tripping all the test was passed but I don't know if this comply with the regs or not so can anyone advice please.
thanks
ben

 

[westward10]

Does it require rcd protection in the first place.

 

[Risteard]

You removed 30mA RCD protection without knowing whether it was required?

I would suggest you would fail the test of a competent person carrying out this work, and therefore have carried out work unlawfully.

 

[westward10]

Rcd + commercial fridges = trouble.

 

[Risteard]

Rcd + commercial fridges = trouble.

Not disputing that. I'm just incredulous that someone would remove 30mA protection without actually knowing whether it was needed or not. Bizarre course of action to take!

 

[Sylvia Namusisi]

Does it require rcd protection in the first place.

Exactly,that is the 1st thing to sort out,if you need rcd or not.

 

[Sylvia Namusisi]

You removed 30mA RCD protection without knowing whether it was required?

I would suggest you would fail the test of a competent person carrying out this work, and therefore have carried out work unlawfully.

Yeap!

 

[Deleted member 26818]

Really?
The OP changed the fuse box, so probably installed the 30mA RCD.
Has now found that the fridges are causing the RCD to trip.
If the fridges are connected using 20A (or lower) plugs then the sockets either need RCD protection or a documented Risk Assessment indicating 30mA RCD protection is not required.
The question should not be whether 30mA RCD protection is required, but whether it can be omitted?

 

[Wilko]

Hi Ben and Welcome to the Forum!
This is a bit of a baptism of fire, but hopefully you'll get the advice you need. My first step would be to find out what is causing the 30mA RCD trips

 

[Ian1981]

The cables supplying the fridges also may require additional protection if concealed in the fabric of the building ie wall <50mm
I don’t believe this regulation can be omitted by a risk assessment, only by other means such as earthed containment etc.

 

[Risteard]

The question should not be whether 30mA RCD protection is required, but whether it can be omitted?

With respect, that's precisely the same question.

 

[Sylvia Namusisi]

Really?
The OP changed the fuse box, so probably installed the 30mA RCD.
Has now found that the fridges are causing the RCD to trip.
If the fridges are connected using 20A (or lower) plugs then the sockets either need RCD protection or a documented Risk Assessment indicating 30mA RCD protection is not required.
The question should not be whether 30mA RCD protection is required, but whether it can be omitted?

He should tell us what the rating for the protective devices are.
Just mentioning 30mm RCDs is not enough
What are the type of circuits these fridges are on?

 

[Nigel]

It soumds mate is if you are a little out of your depth. You cannot just keep changing RCDs until they stop tripping. It does not matter how long the time delay is if you have a neutral to earth fault.

You need to go back to basics and first determin if RCDs are required. Then what rating and where on the installation they should be fitted.

If you have a TT and this is why younhave installed a 100mA S Type then you will need to install 30mA RCDs/RCBOs on the fridge circuits (assuming they require it) that also switch the neutral. If they don’t a neutral - earth fault will take out upstream RCDs.

 

[marconi]

Just a thought - have you thought about inviting a local EF member to join you on site on this one who has more experience of installations requiring or not requiring RCD protection and investigating rcd trips? (Who knows it might open up further joint working opportunities.)