feasibility of three-phase power in mobile catering trailer

[davesparks]

Dave, I understand 4.5.1 is relevant here and that will indeed help the OP in simplifying his inspection and testing, but I am struggling to understand how the OP's scenario could be outside the remit of BS7909 altogether, please can you explain this?

Digressing slightly, 6.2.1 could also come into play - a probable situation if the OP is going to attend private events where another generator will be powering the marquee, toilets & entertainment.
If a caterer advises they don't need any power, most power providers will assume they are bringing gas. When said caterer then rocks up on the day with their own genny, and plonks it close to the set already up & running, this will likely impact on the existing 7909 details of supply signed off, as the METs of both sets may need to be connected.

The OP has mentioned that he is intending to set up shop outside pubs etc, this isn’t events related or related to the entertainment industry as far as I can see.
This is more closely related to street trading and kebab vans at the side of the road.

If the major use of the trailer is outside of the remit of 7909, and when it does stray in to that territory it is powered by the event electricians then I don’t see the issue.

Everyone working in event power knows that catering never know what power to order and expects a request for no power or just a 13A to be far, far more.
Much like we all know to use the old tatty kit to power the fun fair/inflatable attractions because they are going to nick some of it.

 

[hie27]

OK, so an update. I have emailed several trailer builders with the idea and some of the concerns raised here. The trailer still needs a basic kitchen fitted so I have started with the trailer guys first. I had one reply from a chap near Manchester. He said that due to safety and regulations they only put 6kw on each line anyway. He said last month he had one customer that had to have 3 separate lines in they had so many appliances. He suggested a separate line for the 3 phase oven and another 1 one for a few plugs. Basically, he said, it would be just a case of plugging each hookup to a generator that is compatible both 1 and 3 phase instead of messing around with 1 line. He said not to worry about wiring regulations and that he can get the CE certificates.

So far, does this sound like someone who knows what they are really doing? Or should I get the kitchen fitted and seek professional electrician who had dealt with 3 phase.

 

[Strima]

He said not to worry about wiring regulations and that he can get the CE certificates.

That comment has given me Forest Whitaker eye...

He should take a look as Section 7 of BS7671 as this covers wiring of transportable units etc.

 

[Deleted member 105166]

He suggested a separate line for the 3 phase oven and another 1 one for a few plugs. Basically, he said, it would be just a case of plugging each hookup to a generator that is compatible both 1 and 3 phase instead of messing around with 1 line.

The issue with that on a smaller three phase generator, is you will end up with poor load balancing. The three phase oven will draw equally across the three phases whilst the 32/1 hookup for everything else will draw all its load from the phase you choose to put it on, but with nothing else on the other two phases. Not a dealbreaker on a bigger genny, but certainly less than ideal on say a 20kVA set.

He said not to worry about wiring regulations...

That should be ringing loud alarm bells!

 

[davesparks]

Basically, he said, it would be just a case of plugging each hookup to a generator that is compatible both 1 and 3 phase instead of messing around with 1 line. He said not to worry about wiring regulations and that he can get the CE certificates.

Yeah don’t worry about wiring regulations, they only exist to prevent fires or people receiving fatal electric shocks, nothing important.

Setting up multiple small generators in one location sounds like a very tiresome, noisy, slightly dangerous affair which could be a nightmare to safely manage fuel for.

 

[Adam W]

I'm no expert on generators but from what I can make out a generator of this size will need earthing - far from just being a case of finding the best location for trade and turning on the pizza oven, every time you want to trade you'd need to find a suitable place to bang a rod in the ground, then obviously test it, before you can switch anything on, then presumably you'd need to pull the rod back out before you leave.

What I am more familiar with is the kind of questions put to this forum - in most instances it's best to go with the solution everyone else manages with.
This seems to be a case of supplying power to a wood-fired pizza van. I know you've said several times that you don't want to go down the wood-fired route, but that's how the public know the mobile pizza van - they'll be expecting an artisan street food wood-fired pizza. In many cases they'll instinctively ask for a wood-fired pizza, or refer to it as such, to which you'll have to tell them your pizzas aren't wood-fired but use the same kind of oven as the local kebab and chicken shop which also does pizzas, then see if they still like the idea.
Possibly even more important than the food is the theatre of street food - the quirky truck, the rustic signage, words like "fresh, artisan, local, hand-made, (again) wood-fired, the rustic whaft of wood smoke as opposed to the diesel fumes and clatter of a generator.

I'm not saying you can't start up a pizza van using an electric oven, just that it seems to be going against the grain.