Dual Phase

[fletchflash]

Hi all,

Was working in a carehome few weeks ago, the place is on a dual phase supply rather than 3 phase. Its a really big place, about 40 rooms or so.

Ive only ever really seen 2 phases instead of 3 used in a slightly bigger than normal house, where is a 3 phase supply but only 2 phases are used, one for a seperate fuse board.

However, as I said, this place has 40ish rooms, massive loads on 2 phases, multiple submains, kitchen & laundry rooms etc.

Does this not need to be balanced/shared across all 3 phases?

If i remember correctly, its a 3 phase supply coming in, then only 3 wires leave the cutout. I cant remember what the meter looked like to be honest.

How common is this?

ta

 

[steptoe]

not so common nowadays I dont think,

used to be very common when a load greater than single phase was needed, but not so much as 3 phase was justified,

cost you see, as always,

why put in an extra cable if you dont need to, the 3rd phase can be used for the next 4 houses instead.

although, TBH, how much load is actually in a care home apart from the laundry and kitchen?

virtually nil, TV in each room, and maybe an iron(depending on roomies ability) for 15 mins now and again.

 

[fletchflash]

cheers mate

been to few different carehomes for same company. Can't remember what kind of stuff this one in question has, but some have got fair amount of load. maybe big wash rooms, 2-3 big washer then same again dryers, sometimes big 3 phase. Most of them have shower rooms every 3 or so rooms, sometimes with electric showers. suppose diversity would apply as its probably very unlikely all showers be used at once.

 

[steptoe]

when installing anything such as a 3p washer/dryer then it would be down to the installer to verify and check the existing installation can cope with the extra demand, 7671 requires this.

obviously if you check it out and find otherwise, or have doubts then raise the question with your superiors/boss, or if you are SE then with whoever awards you the contract I would suppose.

 

[Andy™]

Hi all,Was working in a carehome few weeks ago, the place is on a dual phase supply rather than 3 phase. Its a really big place, about 40 rooms or so.

Ive only ever really seen 2 phases instead of 3 used in a slightly bigger than normal house, where is a 3 phase supply but only 2 phases are used, one for a seperate fuse board.

However, as I said, this place has 40ish rooms, massive loads on 2 phases, multiple submains, kitchen & laundry rooms etc.

Does this not need to be balanced/shared across all 3 phases?

If i remember correctly, its a 3 phase supply coming in, then only 3 wires leave the cutout. I cant remember what the meter looked like to be honest.

How common is this?

ta

is it 2 phases of a TP supply or split phase (180

 

[fletchflash]

not sure to be honest, going back there week after next, i'll have another look at it.

cheers

 

[binky]

Seen lots of care homes and other institutions like this. Loading is all in laundry / kitchen / central heating, and worst stuf is usually gas, so loads tend not to be as high as you think, but running for long periods of time.

Phase loading was discussed in previous post - did we ever resolve the out of balance loading / cost issue?????

 

[soulman]

hi i have seen a few buildings with two phases only and they all had two energy meters, which confused me, my boss told me the phases do not need balancing? he said you would only balance a 3 phase system. The systems seemed very old, and all used the old mem 3036 fuses then went off to multiple consumer units most of the consumer units were not even swiched on just one or two.