Diversity question

[jedisparks]

Hi all

just got a little diveristy problem im scraching my head on and wondered if someone might be able to help.

New block of 4 holiday/ bed and breakfast challais (excuse spelling)

each challais will have:

low energy lighting throughout about 170 watts in total each
4 double sockets for general purpose, kettle, hair tongs etc.
An electric shower, i have to assume 10.5kw.
1 extractor fan
1 smoke alarm

there will be 1 service cupboard with the heating controls, a socket for a washing machine, and a light. thats about it.

problem ive got is that i need to supply this lot from an existing building which happens to be a pub. 3 phase already connected. Put the old clamp meter around the tails individualy and got 30 amps as the highest on one phase and about 10 amps on another.

what im worried about is over loading on one or more pahses with the electric showers. the on-site guide says to allow no diversity for heating loads but what are the chances of more than one shower being used at the same time?

any ideas are much appreciated.

thanks in advnce

 

[J@mes]

How many beds are there in each chalet? I would be concerned about the showers, as if you have four beds in each chalet, that is 16 people who need to shower, either in the morning or at night (generally when people shower) so there is a high chance of 2 or more showers being on at once, and possibly for long periods if each person takes a 10-15 minute shower.

 

[jedisparks]

Hi J@mes and thanks

Sorry wasnt very clear. there are 4 chalets. each has just one bedroom and an ensuite so they are more like hotel rooms really.

 

[J@mes]

Ah I see. If it were me, I would expect at the very most that only two showers would be on at once if the people occupying them were lone travellers, but if it were a group who had been out walking/cycling or whatever and wanted to shower before meeting for dinner it would be reasonable to expect them all to be used at once!

Tough one really, I think I would apply diversity so that two showers could run at once.

If the showers have not already been installed, I would suggest 8.5KW showers too as these will save you around 8Amps per shower over a 10.5KW one, giving you a bit more room to play with

 

[High Tower]

I would probably balance the 4 chalets over the 2 low phases 2 on each and leave the other that is pulling more to take the load of the pubs single phase requirements and I'm assuming it has managers accom above so that two, other wise you will have one he'll of a mare balancing 4 chalets over 3 phases with one already out.

 

[jedisparks]

Thanks so far everyone

not sure where to go with this now. think i need to make the project manager aware of this and maybe get electricity board involved to give a quote for putting a seperate metered supply to the chalets.

Or go with the 8.5kw showers route and try to balance the loads as best as possible.

Why cant it just be straight forward for a change.

thanks again and anymore input is gratefully received.

 

[Guest123]

How much per phase is the supply to the pub???

 

[jedisparks]

Hi Lenny

Ive not had a chance to look at the fuses but the meter tails are currently 16mm so im assuming 60amps. i would get these upgraded to 25mm and 100amps anyway.

edited

sorry for double post my 1st didnt show up before, strange!