14 new 9.5kw showers to be installed on existing supply

[telectrix]

install a 10KVA generator (2 stroke) outside each shower room. not only will that sort out the loading problem, but starting the buggers with the pull cords will keep the old buggers fit.

 

[sparky351355]

How exactly are you planning on connecting two thirds of a shower to a phase?

I'm not with you dave. It would be 2 5's and a 4.

 

[davethsparky]

You calculation in post number 22 was:

14 x 9500=133000
133000/3
44,330/230=192A

You added up the total KW of 14 showers then divided by 3 and calculated the per phase current from that. To achieve this in the real world you will have to connect 4.66 showers to each phase.

 

[telectrix]

You calculation in post number 22 was:

14 x 9500=133000
133000/3
44,330/230=192A

You added up the total KW of 14 showers then divided by 3 and calculated the per phase current from that. To achieve this in the real world you will have to connect 4.66 showers to each phase.

easy when you've cut out the cable entry and wet-pants has butchered out his pipe entry then melted away half the plastic casing with his blowlamp, that's 0.34 of the 5 showers gone, leaving 4,66.

 

[sparky351355]

I will get 1 three phase shower that will sort it!!!!!!

 

[Guitarist]

Might be worth me raising a concern over the water issue agreed! However i will have 375 A to play with here I'm sure a supply of that size and I'm sure the chances of even 50% of the showers being on at the same time ( even assuming that the the shower is at full wack(9.5kw)) this is manageable , when all that we have is low energy communal lighting and a couple of t.v.s running.

Unless switched to "economy mode", which nobody does, these showers always pull "full wack".

 

[sparky351355]

So nobody is going to come up with a load per phase then !

 

[Marvo]

I think that many instant shower units is a crazy idea. You could run just 3 x 200 litre 4kW hot water cylinders, one on each phase with 5 or 6 showers piped from each cylinder. It would probably cost a fraction of the price and would draw a fraction of the peak load.

 

[davethsparky]

So nobody is going to come up with a load per phase then !

How many rooms are on each floor? as you have suggested you will be going for one phase per floor that will dictate how many showers end up on each phase.

 

[i=p/u]

Share them equally, If fuse blows it blows but you told them to go with power showers..

 

[davethsparky]

Ok i'll play the game here.

Assuming they are split as equally as possible (5,5,4) and as you used 230V in your earlier calculation i'll assume they are rated 9.5KW at 230V.

Total connected load on L1 = 5 * 9.5KW = 47.5kW = 197.9A

Allowable diversity if you consider thsi to be a boarding house = 100% FLC of largest 2 appliances + 25% FLC of all other appliances
Current for 1 * 9.5KW unit = 39.6A
Load after diversity = (2*39.6)+(3*(39.6/4)) = 79.2 + 29.7 = 108.9A

However you could consider these to be individual dwellings in a block then you take 100% FLC of the shower in each dwelling so we get back to 197.9A.

Either way that's going to be a bit much for your existing 100A supply

 

[7029 dave]

you can not applly dievesirty to intantaious water heaters

 

[davethsparky]

Why not?

Guidance note 1 table H.2 lists diversity for Water-heaters (instantaneous type) as 100% f.l. of largest appliance + 100% f.l. of 2nd largest appliance + 25% f.l. of remaining appliances.

 

[i=p/u]

So ok all that's been said , people's opinions , what would you do? , would you do the job or would you say get a plumber in

 

[ruston]

Why not?

Guidance note 1 table H.2 lists diversity for Water-heaters (instantaneous type) as 100% f.l. of largest appliance + 100% f.l. of 2nd largest appliance + 25% f.l. of remaining appliances.

So does the OSG , it's thermostatically controlled that no diversity is allowed.