Three Phase Generator.

big fuel tank with isolator and drain arrangements, but the valves need to be lockable against theft.  Earth as TN-S and yes if there are steels in the foundation below damp course,  connect to them  but also decide where a rod could go if you need one .

Make it very clear that a genset cannot take load step up of more than 30-50% of full load without stalling - quite what will depend on fly wheel mass, but even on a heavy model, no  sudden 20kVA loads please. Frequency and voltage regulation will be much worse than mains also PSC will not be very high Consider an earth fault relay or a 300mA  slow RCD at the origin.

Mike

Thanks Mike.

Z.

How many electric showers ? Might only be three from that size generator. 50 KVA at 0.8 p.f. is about 40 kw. 13 kw per phase=one shower per phase plus a margin for other loads.

Also a generator might not be the best source of electricity for electric showers. The peak loading is substantial, requiring a large and expensive generator. But the average loading is probably fairly low resulting in long hours of low load or off load operation, this wastes fuel and adds to wear.

A "start on demand" generator is a possibility, but they tend not to work well with either showers or washing machines.

Propane for water heating might be better. It is about 20 pence to 25 pence a unit from large cylinders, Presuming that enough water flow and pressure is available, then a 14 kw propane water heater gives a far better shower than most electric showers.

If the electricity CONSUMPTION rather than the PRICE PER UNIT seems excessive, carefully inspect the installation for unauthorised connections.

If there are going to be several people using showers, it makes more sense to use a big water tank with an immersion heater, rather than instant electric showers.

The electric showers are already installed, previously grid powered.  The generator is only going to be used for set periods of time after the "hello campers the showers are available" signal is given. So it won't be run for extended periods. I can't see the system working myself, the site owner has not done his homework before buying the generator.

Z.

If there are going to be several people using showers, it makes more sense to use a big water tank with an immersion heater, rather than instant electric showers.

And as it's a camping site, where presumably the bulk of the load will be in the summer - add a few solar thermal panels and heat the water even more cheaply! (just use the immersion for backup on cloudy days)

+1 for having a think about low loads - overnight the load it likely to be a few hundred watts of bollard lighting - I've heard of some off-grid systems that use a battery system and then automatically start the generator to re-change the battery as needed. Generator then only runs part of the time, and when it does run is used at its most efficient full (or whatever) load.

   - Andy.

The camp site is located in the middle of nowhere so others tapping into the system is unlikely.

I have yet to visit and fully assess the true situation.

Z.

Well here's the thing. The generator has three Ceeform sockets mounted on it. Two blue 16 Amp. types and one red 32 Amp three phase type. A label on the generator says do not allow a load difference of more than ten per cent current imbalance per phase. So is there a problem in running large single phase loads?

Z.

generally single phase gensets need a larger flywheel for much the same reason that a single cylinder engine does - the torque on the shaft is proportional to current flow, and that is much bumpier with a single phase load. With 3 phases the torque due to one winding is falling as another is rising, and the mechanical load is more constant. There is also a problem of voltage regulation - which of your 3 phases would you like to be 230V or whatever - the more heavily loaded one will be lower...

That said some designs can be the full KVA single or 3 phase,  but clearly not this one.

M