commercial kitchen (pub)

[The apprentice]

Hi there just a quick question we have wired a commercial kitchen and work tops, extract canopy, are all metal etc the whole installation will be RCD protected but will we install supplementary bonding shall it be required ? or is it OK with the use of RCD protection thanks in advance really appreciate it

 

[davesparks]

Testing should be carried out to identify any requirement for supplementary bonding.

 

[The apprentice]

Testing should be carried out to identify any requirement for supplementary bonding.

how would you justify doing that ? is the RCD protection ok unless a risk assessment stating otherwise ? and would you consider it an extraneous conductive part

 

[ipf]

how would you justify doing that ? is the RCD protection ok unless a risk assessment stating otherwise ? and would you consider it an extraneous conductive part

That's the reason for the testing.

 

[davesparks]

how would you justify doing that ? is the RCD protection ok unless a risk assessment stating otherwise ? and would you consider it an extraneous conductive part

Why do you need to justify doing that? Nobody with any sense is going to stop you from testing whether something needs supplementary bonding or not.

 

[Lucien Nunes]

RCDs and equipotential bonding are both measures that can protect against shock, but they protect in different ways. An RCD on the kitchen socket circuit will protect against shock from touching the line conductor of that circuit. In the event of a fault elsewhere on the system that raises the MET above true earth, the RCD won't react because it's not the socket circuit that's faulty, but the sockets' CPC will carry that raised MET voltage to all earthed appliances connected plugged into them. A shock could then occur between an appliance and the canopy, if that is connected to an extraneous duct that brings true earth into the area. Bonding the canopy ensures that whatever voltage exists, is the same on everything.

 

[pc1966]

I don't know if the regs say anything about this specific situation, but with the kitchen you describe there will be multiple metal objects, wet hands, high current appliances, and potential paths to the outside world via service pipes.

Sounds like a high risk environment to me!

 

[Midwest]

Bonding the canopy ensures that whatever voltage exists, is the same on everything.

Surely the canopy requires testing to see if it extraneous or not, before its bonded?

 

[Ian1981]

There is usually no requirement to earth or bond kitchen furniture unless they are actually extraneous conductive parts which I’ve never come across one which actually is.

Edit , one time a metal sink was connected to a metallic waste which went outside and into the ground but other than that.

 

[pc1966]

Just wondering when you say "whole installation will be RCD protected" are all supplies on 30mA RCD/RCBO that offer shock protection, or are some circuits (e.g. commercial oven) on MCBs and/or 100mA/300mA RCD (fire protection, etc) in case of high leakage?