Looking to install a 3ph supply for 2 x 6kW fryer in a commercial kitchen.

[James.B]

Thanks Ian and Telectrix, yes my In is greater than my Ib and my Iz is greater than my In. If I used 4mm cable as mentioned before, my It would not be greater than my Iz using the 70 deg C tables, but i believe this (condition 3) unessary to meet once condition 1 & 2 are met. In saying that, I now plan to use a 6mm cable anyway therefore my It will be greater than my Iz. I see many people have mentioned about not protecting by an RCD, but I believed this was only the case where the RCD was nigated by a Risk assessment (411.3.3), personally I would prefer to fit one and would not nigated it. But would you be so kind as to maybe give reference to where the regs states this if other than by a Risk assessment? Many thanks, James?

 

[Ian1981]

Thanks Ian and Telectrix, yes my In is greater than my Ib and my Iz is greater than my In. If I used 4mm cable as mentioned before, my It would not be greater than my Iz using the 70 deg C tables, but i believe this (condition 3) unessary to meet once condition 1 & 2 are met. In saying that, I now plan to use a 6mm cable anyway therefore my It will be greater than my Iz. I see many people have mentioned about not protecting by an RCD, but I believed this was only the case where the RCD was nigated by a Risk assessment (411.3.3), personally I would prefer to fit one and would not nigated it. But would you be so kind as to maybe give reference to where the regs states this if other than by a Risk assessment? Many thanks, James?

411.3.3 is the regulation you want for omission of additional protection by a risk assessment

 

[telectrix]

Thanks Ian and Telectrix, yes my In is greater than my Ib and my Iz is greater than my In. If I used 4mm cable as mentioned before, my It would not be greater than my Iz using the 70 deg C tables, but i believe this (condition 3) unessary to meet once condition 1 & 2 are met. In saying that, I now plan to use a 6mm cable anyway therefore my It will be greater than my Iz. I see many people have mentioned about not protecting by an RCD, but I believed this was only the case where the RCD was nigated by a Risk assessment (411.3.3), personally I would prefer to fit one and would not nigated it. But would you be so kind as to maybe give reference to where the regs states this if other than by a Risk assessment? Many thanks, James?

how will the fryers be connected? hard wired or on plug? and will cable be buried <50mm in wall?

 

[plugsandsparks]

As a fryer presumably has no switch-on surge of any note (maybe small motor for oil circulation?) I don't see any reason for a C-curve MCB and the B-curve version will make the required Zs far easier to meet.

I think the only issue i can see is getting TP B curve breakers for that board, TBH its getting harder and harder to meet ELI with the values dropping as they do. Did an EICR on an office ring that was put in 10 years ago on a c32, failed today just outside ELI, its a MEM board , nothing wrong with the cct, hey ho

 

[James.B]

As a fryer presumably has no switch-on surge of any note (maybe small motor for oil circulation?) I don't see any reason for a C-curve MCB and the B-curve version will make the required Zs far easier to meet.

Hi PC, the reason for me using C Type 32 was because I have one, and the DB is the old Crabtree Polestar 125A, discontinued about 10 yrs ago, but point noted and I agree. With a Ze of 0.1 on a TN-C-S and using a 4 core 6mm swa using the armour as my cpc cleated direct on a run of less than 15m I'd expect a pretty decent Zs, sub 0.2, so hopefully no foreseeable issues and will also be RCD protected, cheers James?
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411.3.3 is the regulation you want for omission of additional protection by a risk assessment

Thanks Ian I thought that was the only reg alright, appreciate your time mate?

 

[marconi]

JamesB: I admire the care you are taking with the required analysis and that you record it too ( - I assume) for posterity - just in case. Well done , Sir.

Plenty of great advice from some leading runners in the game.

Did your client consider 'induction fryers'? A lot more efficient and quicker.

Induction Fryers, Buy Online UK | Nisbets Induction Cooking Machines - https://www.nisbets.co.uk/catering-appliances/cooking-equipment/induction-cookers/induction-fryers/_/a33-4

View: https://www.youtube.com/watch?v=7GcMRCUw2J0


I recommended 2 x 3kW to my brother-in-law to make best use of a very limited single phase power supply to cook chips at football ground catering van.

 

[James.B]

how will the fryers be connected? hard wired or on plug? and will cable be buried <50mm in wall?

Hi Telectrix, fryers will be wired via a 32A 5 pin plug and socket, with rotary interlock switch and RCD protected. Using a 4 core 90 deg thermosetting swa cleated direct and with pirana locking nuts. With the rotary isolator being of plastic construction I'll gland into a metal J.Box first and into the isolator from that, unless there's a better option on the market these days that I don't know about??? Open to other options, and appreciated, many thanks?

 

[telectrix]

if the 32A socket is dedicated to the fryer, my thoughts are that RCD may not be required. A written RA might be advisable.

 

[James.B]

JamesB: I admire the care you are taking with the required analysis and that you record it too ( - I assume) for posterity - just in case. Well done , Sir.

Plenty of great advice from some leading runners in the game.

Thank you Marconi, yes some good advice from people that I appreciate, to be able to so called, bounce off, things change so quickly in this industry and it's good to be able to come on here and if you have an issue or a doubt, then put it out there. As they say that's what this forum is all about, and everyday is a learning day, none of us know everything and sometimes can even forget our basics no matter how much experience we have?. A guy said to me many years ago, cover your --- and sign any legal document as if you are standing in a court of law. I guess old habits die hard ?. Appreciate your feed back, thanks James?
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if the 32A socket is dedicated to the fryer, my thoughts are that RCD may not be required. A written RA might be advisable.

It is dedicated to the fryer, at this moment in time, the problem is I know the owner and I also know he changes his mind like the wind and it may be used for something else in the future, therefore I'd prefer to cover my --- as they say, I know there is the cost element, but that's on him and I walk away with a clear conscience knowing all is well. In saying that I appreciate your informative info, many thanks again?
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JamesB: I admire the care you are taking with the required analysis and that you record it too ( - I assume) for posterity - just in case. Well done , Sir.

Plenty of great advice from some leading runners in the game.

Did your client consider 'induction fryers'? A lot more efficient and quicker.

Induction Fryers, Buy Online UK | Nisbets Induction Cooking Machines - https://www.nisbets.co.uk/catering-appliances/cooking-equipment/induction-cookers/induction-fryers/_/a33-4

View: https://www.youtube.com/watch?v=7GcMRCUw2J0


I recommended 2 x 3kW to my brother-in-law to make best use of a very limited single phase power supply to cook chips at football ground catering van.

Thanks Marconi, I did see these when I was looking up the fryer he speced, I'm sure he's seen them but seems adamant about this particular one, another reason why I speced a 32 breaker instead of what would have been a 20 for this load was that there is a twin 9kW fryer available, so I wouldn't put it past him to go for that ??, cheers anyway?