Oven Replacement - RCD?

[lozarus]

Afternoon all. Apologies if this is a stupid question. I'm currently half part way through completing 2391 (second exam tonight) - so may be getting myself in a tiz overthinking things.

Either way, thought I'd put it out to the group.

Task is: Straight swap of existing x5 ovens with new - "like for like", if you will. Albeit cooker plate to appliance is also in T&E and I intend to replace this with a more suitable product - namely HO7.

Earthing arrangement is: TN-S.

Environment is: Educational establishment, cookery rooms.

Circuits for the room originate in a local 3P+E MEM2 board, no RCD's. Ovens are simply domestic 1P+E bog standard, cheap household jobs, wired from C32's at the DB to 45a Isolators (no socket) at each station, cooker outlet below. Room is only about 10m long.

EICR from 2020 is available, but quite a few tests missed out - IE: Zs for each oven measured well within limit. No IR or R1+R2 undertaken - I'll be doing this anyway. It's all PVC T&E - mainly in metal trunking. I think it's loose behind the cabinets for the last few metres however.

My big question here is RCD. I could take the "like for like" approach and just straight swap the ovens out as "maintenance". But the environment (education) makes me think I really should be pushing for RCD's.

Further to this, manufacturers instructions state "Additional protection by RCD is recommended".

With that in mind, I'm convincing myself these really should be going onto RCD shouldn't they?

Or convince me I'm wrong. Sorry if I've overcomplicated a simple job here.

Thanks.

 

[default]

Afternoon all. Apologies if this is a stupid question. I'm currently half part way through completing 2391 (second exam tonight) - so may be getting myself in a tiz overthinking things.

Either way, thought I'd put it out to the group.

Task is: Straight swap of existing x5 ovens with new - "like for like", if you will. Albeit cooker plate to appliance is also in T&E and I intend to replace this with a more suitable product - namely HO7.

Earthing arrangement is: TN-S.

Environment is: Educational establishment, cookery rooms.

Circuits for the room originate in a local 3P+E MEM2 board, no RCD's. Ovens are simply domestic 1P+E bog standard, cheap household jobs, wired from C32's at the DB to 45a Isolators (no socket) at each station, cooker outlet below. Room is only about 10m long.

EICR from 2020 is available, but quite a few tests missed out - IE: Zs for each oven measured well within limit. No IR or R1+R2 undertaken - I'll be doing this anyway. It's all PVC T&E - mainly in metal trunking. I think it's loose behind the cabinets for the last few metres however.

My big question here is RCD. I could take the "like for like" approach and just straight swap the ovens out as "maintenance". But the environment (education) makes me think I really should be pushing for RCD's.

Further to this, manufacturers instructions state "Additional protection by RCD is recommended".

With that in mind, I'm convincing myself these really should be going onto RCD shouldn't they?

Or convince me I'm wrong. Sorry if I've overcomplicated a simple job here.

Thanks.

This is a commercial install. No 30mA protection need as long as all the bonding is as it should be.

 

[westward10]

The fact it is a school does not enforce the requirement for rcd protection. The fly in the ointment is the manufacturer 'recommending' rcd protection so read that as you will, recommending does not necessarily insist on it being done. Provided the existing devices satisfy ADS then to me it is fine.

 

[lozarus]

The fact it is a school does not enforce the requirement for rcd protection. The fly in the ointment is the manufacturer 'recommending' rcd protection so read that as you will, recommending does not necessarily insist on it being done. Provided the existing devices satisfy ADS then to me it is fine.

Yes, that does make sense. The reccomendation is indeed the main point that was bothering me. I suppose the theory behind this is to put the onus back on the installer.

 

[SparkyChick]

I would be very careful with the word 'recommended' right now... my understanding is that amendment 2 introduces a handy definition which implies "recommended" = "should". This has come to my attention specifically in relation to the installation of arc fault detection devices, but it's not beyond the realms of possibility that all recommendations are now must do's.

 

[westward10]

I agree you can see why they included it.

 

[Pretty Mouth]

The BSI have taken a common, well defined word, that everyone understood perfectly from an early age, and re-defined it to something that doesn't tally with the dictionary definition, so now we're all confused about it. If they mean 'should' then why not use the word should.

 

[SparkyChick]

The BSI have taken a common, well defined word, that everyone understood perfectly from an early age, and re-defined it to something that doesn't tally with the dictionary definition, so now we're all confused about it. If they mean 'should' then why not use the word should.

I would suggest it's the manufacturers sitting on the various committees that are driving things these days. Feels like things are changing just to sell more gear. I've got a situation at the moment where if I comply fully with the regs, a consumer unit that would cost £240 (this is for a BG board - only one that will fit with SPD and RCBOs) is going to cost well in the region of £850 because there are four socket circuits. I could potentially reduce that to maybe £550 by connecting three (old radial heater supplies with a single socket on each) of them together but overall, it's a ridiculous situation so now I'm thinking of having the client decline the AFDD option and record it as a departure. This is one bed cottage that needs a satisfactory EICR to comply with the Welsh rental laws. Currently two 3036 boards, everything is spot on apart from a socket outlet with a cracked face and rotting backbox... except it has no additional protection (has a 100mA upfront - TT earthing).

Recommended means you should really, but it's still optional.

As you say, they've redefined a word... still... that seems to be the game everyone is playing these days

 

[default]

I would suggest it's the manufacturers sitting on the various committees that are driving things these days. Feels like things are changing just to sell more gear. I've got a situation at the moment where if I comply fully with the regs, a consumer unit that would cost £240 (this is for a BG board - only one that will fit with SPD and RCBOs) is going to cost well in the region of £850 because there are four socket circuits. I could potentially reduce that to maybe £550 by connecting three (old radial heater supplies with a single socket on each) of them together but overall, it's a ridiculous situation so now I'm thinking of having the client decline the AFDD option and record it as a departure. This is one bed cottage that needs a satisfactory EICR to comply with the Welsh rental laws. Currently two 3036 boards, everything is spot on apart from a socket outlet with a cracked face and rotting backbox... except it has no additional protection (has a 100mA upfront - TT earthing).

Recommended means you should really, but it's still optional.

As you say, they've redefined a word... still... that seems to be the game everyone is playing these days

Is not having an AFDD a departure? And you could you fit an SPD in a separate unit before the boad? Or get them to sign saying they understand they should have it but do not won't it.

 

[SparkyChick]

Is not having an AFDD a departure? And you could you fit an SPD in a separate unit before the boad? Or get them to sign saying they understand they should have it but do not won't it.

I would say absolutely 100%, if you don't install AFDDs where they are required it's a departure and as I've outlined above, the regulations and the definition of "recommended" mean they are required in all domestic settings.

But that's just my interpretation, I'd be more than happy to be proven wrong.