Log Cabin / Campsite Installation

[afswift]

Hi,

Been asked to price a job which has the possibility of wanted a power installation to 10 log cabins added to an existing campsite which is part of a pub.

Having only just started out and purely focusing on domestic work (only a domestic installer) i turned the job down, due to it been a commercial environment and also not the size of jobs that iam currently involved with.

But it did make me wonder how this sort of installation would be done, obviously a lot of calculations & designs would be done.

I would thought that a large submain cable SWA would be taken from the incoming supply at the pub? Fused switch first. 3 Phase?

Then a large DB in some sort of service hut n the camp site? Main circuit breaker for each cabin? Main RCD for whole installation? then smaller SWA to each cabin, then a small m/c consumer unit with 30ma RCD and wiring to sockets & lights in pvc conduit.

The only problem i can see thats obvious is that if the pub only had say 80A / 100A per phase supply on the incomer then, surely this would not be sufficient to provide power to the pub and the cabins.

This is only my guess, would be interested in what the commercial sparks would do in this situation.

 

[Taylortwocities]

Hmm a nice C&G2400 question (or whatever they call it now).

Well . The very first step is to assess the demand for each cabin. What is to be powered up?
What is the heating
ARe there power showers
Number of rooms, sockets etc
Appliances

Or, if it is smaller, then design much like a caravan site supply set.


Use basic design principles and multiply by the number of cabins, then there is a diversity factor per cabin and per group (assumes not all cabins are in use at the same time). The same sort of principles as used in power requirements for, say, a block of flats.

Without a doubt there would be a requirement for separate power from the pub.

Definately NOT one RCD for the whole lot - do not forget not to have a single point of failure! One dodgy kettle & all the cabins lose their power!

 

[afswift]

Thanks for the quick reply. might have a go at working it all out if i get chance this weekend, Good revision of my 2330 stuff!! would also be interesting on the sizes of cable required, taking into account for volt drop etc.

Having a seperate power supply from the pub? would that be a complete seperate intake meter etc, i.e out of the electricians control, responsibility of the dno?

 

[flameport]

This all depends on what is going in the cabins. Could be anything from a loo and a lightbulb to a full kitchen and bathroom with electric showers.

Assuming moderate loads in each cabin (no electric showers or other heavy duty appliances), one way would be:

Suitably sized circuit breaker at the main intake, and then a SWA cable to each cabin in turn. At each cabin, the 2 ends of SWA joined in an external cabinet.
Isolator and suitable size circuit breaker in cabinet.
Cable from the external cabinet to a 4 way enclosure inside each cabin with 2x DP RCBOs for lighting and socket outlets.

Might need earth rods at each cabin, particularly if there are metal water or gas pipes to the cabins.

The main SWA could be a radial, ending at the last cabin, or a ring could be useful, particularly if the cabins contained high powered items such as electric showers.