Commercial kitchen from home

[round23]

Hi,

I'd be getting an electrician to complete any work but would still like an idea first on what is and isn't possible and the best way of going about it.

In a nutshell, we are looking at converting the spare area of our dining room into a mini-commercial kitchen by mainly using electrical counter-top equipment. Already we have 4 x 5 ltr fryers (2.8kW each @ 240V) and a griddle (2.2kW @ 240V). Based on my calculation this is roughly 58A and will instantly trip the 32A breaker that the sockets are currently on.

Is it possible to increase the 32A capacity?
If so, would this be a large job involving re-wiring all downstairs sockets to something like a 6mm cable and increasing the maximum capacity of the circuit board from 100A?
Any ideas and ball park costs I would be looking at?

Many thanks

 

[stevethesparks]

I would suggest a dedicated consumers unit/dis board be installed locally and feed each item separately. A small dedicated final ring circuit (socket outlets) could also be incorporated for smaller portable/low load items. This would also allow if required separate metering to allow separation of the billing between home and commercial costs. More info required really.

 

[Lister1987]

Give us as much detail as you can in terms of frequency of use,what you're likely to run when,any running at the same time, average run time of each appliance (makes/models/specs would also help). Are they going to be on constantly?

As no doubt any of my fellow members will say; speak to an electrician, draw up a design and go from there, you don't have to go with whatever the Electrician suggests but it is vital to consult one at what is effectively the design phase.

You may find a lot more is required than you think, depending on factors like loading of existing, current demand Vs maximum demand, whether or not your existing service fuse will be adequate for the additional demand.

 

[Strima]

You also need to take into account additional lighting and ventilation systems.

 

[James]

With all that heat and 20L of hot oil , a professional fire risk assessment would be a really important first step.
This may bring up a number of Things to include in your plans.

 

[Deleted account]

I like Steve the sparks idea of a local Cu for the new kitchen but I think I’d put each appliance on a separate circuit Rather than a ring.

wiring guidelines are that appliance over 2kw should have there own dedicated supply ( separate circuit).

 

[stevethesparks]

I like Steve the sparks idea of a local Cu for the new kitchen but I think I’d put each appliance on a separate circuit Rather than a ring.

wiring guidelines are that appliance over 2kw should have there own dedicated supply ( separate circuit).

I did mention supplying each item separately

That would have been the reason for the dedicated CU

 

[Deleted account]

I did mention supplying each item separately

That would have been the reason for the dedicated CU

Oops sorry. re read. Yes you did say that.

in that case we are in total agreement.

 

[stevethesparks]

As said more into required.
There isn’t a great deal of load mentioned, assuming both the commercial side and domestic kitchen will not be in full flow at the same time?
It will be up the the electrician of the day to sort that out.

 

[Taylortwocities]

increasing the maximum capacity of the circuit board from 100A

Most domestic supplies have a service fuse that can be as low as 60amp. It could be 80A or 100A. You can enquire with your DNO to find out what your supply is limited to. You can ask for an upgrade, but the maximum domestic single phase supply is generally 100amps. To go more than that would mean the installation of a three-phase supply, unless you already have one then you can ask the DNO the cost to do this. Be sitting down when you get the quote though. It may be cheaper to rent a commercial kitchen that already exists. Plenty of pubs sitting empty right now.

 

[round23]

Appreciate all the responses.

As a little more information, my current kitchen is ‘U’ shaped with a half wall separating it from the dining room. We are looking to install this addition section along a 3m wall so it’s not a huge space...circa 2m of worktop space after installing an America fridge-freezer.

What I’ve listed (I.e. fryers and griddle) would be the main consumption and the only thing that may be used at the same time would be the electric oven in the current kitchen (gas hobs). It would be beneficial to have the capacity to add one or two more appliances in the future though.


I like the idea of a locally installed consumer unit to separate the usage. How would this be done and what type of costs are we looking at?

I had a quote a few years back for a 3-phase installation when my parents were creating a self-contained flat in an outbuilding and it wasn’t cheap! They ended up removing the kitchen and just running it from the main house and using an LPG boiler for hot water!

 

[stevethesparks]

Now you are adding more into the mix, its looking more likely you will need either a separate supply or a 3 phase supply. Would gas ovens as well as hobs would be a consideration? You need to plan with the bigger picture from the outset, rather than try to add on in the future.

 

[Vortigern]

Having had a fair amount of experience around commercial kitchen fit-outs and repairs I would say that your current idea is conservative. What tends to happen as you get successful is the demand for more points etc. for more appliances. It is highly unlikely you could successfully run a commercial kitchen from a domestic supply ultimately. What I tend to see is sockets burnt out often due to this kind of thing. A picture of your consumer unit and cut-out would help to advise more clearly. As above ideas cost wise I would say £1-2k dependant on what you have and what you really need.

 

[Dustydazzler]

Dedicated supply via a sub main to a new DB for the new kitchen circuits, will be the best future proofed method. Gives you flexibility to add / remove circuits as and when necesstry.
put a bog enough board in allowing plenty of expansion

 

[Intoelectrics]

Hi,

I'd be getting an electrician to complete any work but would still like an idea first on what is and isn't possible and the best way of going about it.

In a nutshell, we are looking at converting the spare area of our dining room into a mini-commercial kitchen by mainly using electrical counter-top equipment. Already we have 4 x 5 ltr fryers (2.8kW each @ 240V) and a griddle (2.2kW @ 240V). Based on my calculation this is roughly 58A and will instantly trip the 32A breaker that the sockets are currently on.

Is it possible to increase the 32A capacity?
If so, would this be a large job involving re-wiring all downstairs sockets to something like a 6mm cable and increasing the maximum capacity of the circuit board from 100A?
Any ideas and ball park costs I would be looking at?

Many thanks

Have you had any advice on planning permission etc...? If you are looking at business use then there may well be requirement for it. You may need a proper architectural design for building regs and planning submission. There will also be insurance and risk assessments (as James ^^ mentioned) to consider...

Not trying to put you off, but making sure you are aware of all the considerations before you start spending your money.

 

[round23]

I have attached a picture of the consumer unit and also the floor plan to help clarify what the aim is.

The aim at the moment is for my partner to set up something small scale on the side, hence why we are looking to run it from home to begin with. The ultimate goal (post-covid) is to expand and look at a permanent commercial premises which will remove these limitation.

As you'll seen in the floor plan though, the current kitchen is fairly small and consist of electric oven, gas hobs, fridge/freezer, dishwasher and washing machine.

On the other side of the half wall we have a double fridge/freezer and a table top with the below equipment:
Fryers - (Voltage: 230V, 50Hz) (Power: 4 x 2800W) (Current: 4 x 12.2A)
Griddle - (Voltage: 230V, 50Hz) (Power: 2200W) (Current: 9.6A)

As you'll also see- there's not really a lot of room for expansion/additional equipment so if I could accommodate for the above with a little additional capacity for some breathing room that would be more than sufficient.

I was thinking that it would hopefully be a job I could get an electrician in for but wouldn't be that large of a job for planning permission. We'll also be looking to get a fire risk assessment and make sure everything is in order.

If the costs are going to be in the £1-2k range that would be reasonable but then if the only way was a three-phase supply running into the several thousands plus then that won't be an option for me.

 

[James]

I think what you are planning is feasible, I would ask a couple of local electricians to quote, there may well be some on here that are happy to quote if you ask.

My suggestion would be a single cable from your existing board, run to a new board in the room you intend to kit out.

from there, surface mount in conduit to all the new sockets, again surface mounted sockets.

1 to 2 days work, 300 to 600 for materials would be my guess.

when you eventually need to turn it back into a domestic room, it is as simple as removing the single cable that feeds the new board and removing all the surface mounted stuff. bit of pollyfilla in the holes and you are good to paint it.

 

[WallyWest]

I've been down this road, you will end up getting 3 phase service.

Are you actually running this as a commercial business? I'm in the food production business myself, and have done it from home. Back when I did it (in PA) it was annoying to comply with all the regs. Now it's nearly impossible.

Depends on the state, some are worse than others. And fryers are super expensive to run. Are you installing a commercial hood vent with fire suppression over them? Trick question, you ARE doing that whether you want to or not once the inspector rolls in. They are not cheap.

 

[James]

what they suggest is possible in the uk, although there are things to consider we are not quite as tied down with legislation as you are in the states.

 

[round23]

I think what you are planning is feasible, I would ask a couple of local electricians to quote, there may well be some on here that are happy to quote if you ask.

My suggestion would be a single cable from your existing board, run to a new board in the room you intend to kit out.

from there, surface mount in conduit to all the new sockets, again surface mounted sockets.

1 to 2 days work, 300 to 600 for materials would be my guess.

when you eventually need to turn it back into a domestic room, it is as simple as removing the single cable that feeds the new board and removing all the surface mounted stuff. bit of pollyfilla in the holes and you are good to paint it.

Is there a specific forum where I could find a local electrician?

Would this single cable come from the spare 32A breaker on my existing board as this wouldn't be enough? I like to understand what's happening and having done a little bit of looking I've seen that henley blocks are used to install sub-consumer units?

I like the idea to surface mount though so I can easily put it back to normal in the future.

 

[pc1966]

Would this single cable come from the spare 32A breaker on my existing board as this wouldn't be enough? I like to understand what's happening and having done a little bit of looking I've seen that henley blocks are used to install sub-consumer units?

Ideally you don't want the kitchen CU off your existing RCDs as the leakage on those ovens is likely to trip it taking out the kitchen and some of your home supply.

If your CU allows internally a 63A (or maybe 50A) MCB off the direct supply (i.e. from main switch to RCD input, not RCD outputs) then it would be better, but still not offering much selectivity. In other words if you have a big fault on one kitchen circuit it will also trip the supply MCB taking out all of the kitchen electrics. So don't put your lights on it with this configuration as that would be very dangerous. Probably you should look at some sealed "non corrosive" LED strip-lights with built in emergency backup anyway, just in case you are running lots of hot appliances and the mains fails plunging you in to darkness.

That is why the usual suggestion is to split the tails feeding your main CU (where the Henley blocks come in) and then have a fused-switch to feed the sub-main cable to the 2nd CU. The selectivity between a 63A fuse and something like a 20A MCB or RCBO for the cookers is quite good so a fault would be localised to the final circuit.

Generally you should have all of the final circuits on RCBO if you can, though if the ovens are hard-wired (e.g. FCU) and the cables not buried < 50mm they could have RCD protection omitted. Socket outlets should always have RCD protection.

 

[stevethesparks]

You really need to list every single item with their rated values. You also need to advise what sort of loads the normal household has. ie electric showers - how many, car charging points, current domestic kitchen set-up etc. What hours would the business side run, could you honestly run the business side and near enough shut off the living arrangements at the same time? If not it looks like there may be a possibility of a total power outage at some stage.

 

[pc1966]

The total mentioned above is 58A without allowing any diversity (I would be cautious about how much is allowable for commercial kitchen?).

So long as no showering and no big EV charging during working hours they may be OK on a normal supply, but wise to check if it is 60/80/100A.

 

[stevethesparks]

The total load was 58 amps before the electric oven was mentioned/added, no mention of a possible microwave?
It really needs someone to visit site and make a proper evaluation.

 

[pc1966]

The total load was 58 amps before the electric oven was mentioned/added, no mention of a possible microwave?
It really needs someone to visit site and make a proper evaluation.

Yes, I should have read it more carefully as the oven (probably 10-15A) and dishwasher (same again?) all pushes up the peak demand.

If they have 100A (or can get upgraded to it) then it is looking OK, but dodgy for a 60A supply.

 

[pc1966]

Out of curiosity I looked up to OSG table A2 for diversity on non-domestic cooking and it suggests:

• 100% of max demand appliance +
• 80% of next biggest +
• 60% of the rest.

Here they are all roughly the same so it is leading to around a 70% overall factor taking 58A to 40A-ish. but the concern would be at start of they day putting on all fryers to get them to temperature and maybe a coupler of other things as well.

 

[stevethesparks]

Plus kettle/water boiler, toaster, I don't think the whole thing has been thought through enough.
I hope I'm wrong and they can make a good go of it.

 

[pc1966]

It is sort of pointing to a 100A supply and 63A fused sub-main as being OK, but as just said it really needs a proper study of what is going in there.