New connection/Additional Service Head

[monkey5]

Evening all,

ive been to a new house which is huge, and i mean huge.

basically there having 2 new hot tubs in 6 weeks or so and wasnt sure if there incoming supply would be able to carry it.

i was expecting a 3 phase supply when i pulled up, but it only had 100A single phase supply. This must be not far off the full demand, gonna put a clamp meter on next time on just out of curiousity.

Can a new supply head normally be looped from the existing or will it need to come from the road.

am gonna ring eon tomorrow or thurs when i get 5 mins! but just wondered what your experiences are.

cheers wayne

 

[ProDave]

It all depends how big the supply cable is.

I went to price a job rewiring part of a 3 storey country pile. I was astonished to find just a single phase 100A supply terminating in an adjoined barn, that then fed the whole of the 3 storey house AND two adjacent cottages as well.

I advised an upgrade to a 3 phase supply, but I didn't get the job so I don't know the outcome.

 

[a1]

Monkey, what did eon say, mate?

 

[Evans Electric]

I've known them fit a second 100A fuse .

We took some houses over for a builder who had got rid of the sparks who 1st fixed them , never found out why.

They had used inferior cable, grey sheath could be removed with thumb and forfinger, and no board for the off peak heating , DNO had not been informed that houses were all electric.

They just fitted a second 100A fuse to a very small looking incomer .

 

[monkey5]

still not got in contact yet, only had chance on friday and it was shut till tues so will try then. will update as soon as i know anything.

wayne

 

[monkey5]

UPDATE:

Eon said they were responsible so sent all docs off, 1 week later they send all stuff back saying they are not responsible need to contact YEDL. fill in the forms for YEDL and they finally came to look on 12th. they went away and came back yesterday with price for customer and the plan of action.

customer digging trence ane YEDL connecting up a three phase for about

 

[steptoe]

depends on the meter, but it doesnt go on the largest usage and treble like some people would have you believe,

But,

you really do need to try and keep the phases balanced, remember the neutral isnt very large compared to the phases,

 

[apprentice87]

Hi, I got a three phase meter, a modern electronic one, just the same as you will have fitted i expect. Obviously you need to try to balance the load over the phases, or taken to extremes, you will be no better off than before!!

Out of interest, why would you want three seperate Cu's when you could have just the one three phase one fitted with single pole MCB's

Apart from this, and others will know more about this than me, i think you are going to have to be careful what you put on what phase. So far as i know your are not meant to have things on different phases within 2 meters of each other, but i am not sure about this. What i do know, is that if it means that you will have 400V between components, where usually it would be expected that the PD would be only 230V, than you must have a sign to this effect.

Obviously it would not be safe to have your electric kettle on one phase and your fridge under the worktop for example, on another.

Back to the meter; It has only got a single "dial" [ok, it is an LCD display] but it makes no difference to the meter at all if you connect a load to all three phases, between two phases, or separately between all three phases and neutral. Mr Meter just does its calculations and comes up with the power used [Ok not strictly the "power", but you know what i mean!!]

john..

 

[monkey5]

Hi, I got a three phase meter, a modern electronic one, just the same as you will have fitted i expect. Obviously you need to try to balance the load over the phases, or taken to extremes, you will be no better off than before!!Out of interest, why would you want three seperate Cu's when you could have just the one three phase one fitted with single pole MCB's

Apart from this, and others will know more about this than me, i think you are going to have to be careful what you put on what phase. So far as i know your are not meant to have things on different phases within 2 meters of each other, but i am not sure about this. What i do know, is that if it means that you will have 400V between components, where usually it would be expected that the PD would be only 230V, than you must have a sign to this effect.

Obviously it would not be safe to have your electric kettle on one phase and your fridge under the worktop for example, on another.

Back to the meter; It has only got a single "dial" [ok, it is an LCD display] but it makes no difference to the meter at all if you connect a load to all three phases, between two phases, or separately between all three phases and neutral. Mr Meter just does its calculations and comes up with the power used [Ok not strictly the "power", but you know what i mean!!]

john..

cheers john. the property is a large one and already has 2 cus one for the house the other for the garage and outdoor things IIRC. the reason i went was they are have 2 very large hottubs and i said the incoming supply would not be good enough so to see what DNO could do. theyre gonna fit a 3 phase supply but customer doesnt want to change the existing CUs(2 years old max) so wanted 1 on each phase then the hot tubs on a phase in new CU just for them.

im thinking the circuits are probably seperated the best they can be at the min with out have 2 phases in location. but will have a proper look at this when there next.

would you need to mark the sockets etc which are on different phases or just label at the CUs.

cheers

 

[batty]

I would be very careful that you don't have two phase in a switch etc. Three phase on a domestic needs a lot of thought.

 

[steptoe]

and think about it, having a phase for the garage isnt really balancing loads out much, is the garage going to be drawing a 3rd of the juice at the same time the others are?

or vice versa, the 2 hot tubs are unlikely to be in use while the oven and 2 showers are being used,

ALL 3 phases need to be split evenly across the property, not just simply putting different areas of the house on different phases.

 

[Sidewinder]

Also, I would be wary of having 400V 3ph in a "special location" without suitable precautions.

e.g if the lighting & small power in the hot tub rooms were on say the red phase and the hot tubs were on yellow that could be an issue?

 

[steptoe]

3ph in domestic can(usually) be a nightmare trying to split and divide loads equally, while still trying to keep each area on one phase.