Electricity rating for house

[Lavanda]

Happy New Year to Everyone!

Our town house has a Potencia Contract with the electricity suppliers of 3.30 kw. We 'trip' the electrics quite regularly when we have lots of things on at the same time. Does anyone know what the 'normal' kw level should be for a 'normal' house?

[Kmoppz]

Ours is 3.3kw, we have a 2 bed house,but our old 2 bed apartment had 9.9kw.

Not sure if this would be the cause for it 'tripping' probably that you are exceeding the rating for the trip switch on a particular circuit.

I'm no sparky, so probably barking up the wrong tree...

[El Cid]

3.3kw is pretty common for a new installation in an average holiday home. That way the standing charges are kept to a minimum.

For an average "lived in" house 5.5 is about adequate and you would only trip that if you really had everything on. With aircon and other electric heating and large pool pumps etc. then 8.8 would be better. If you want over 10kw then that would require you to have a 3 phase installation.

Assuming the electricity installation is rated for a higher figure then it is easy to get it upgraded - they just change the potencia trip for a bigger one. The extra standing charge is about 2 euros a month for each Kw of rating so to go up to 5.5 would cost about 5 euros a month.

Sid

[Don]

That interesting Sid. I have a 3 phase input but only had a 3.3 kW rating until I suffered a fire in the "fusebox" and when the electrician fitted a new box and cables he said that he had upgraded the connection to 5.5 as it was the same minimum price anyway. I still believe he has some crossed connections somewhere as there is an old doorbell repeater on the back wall which pulses continuously if connected so it remains unconnected even 4 years after the fire and after he promised to come back and sort it "manana". We used to trip very easily if dishwasher and washing machine were both on in addition to things like kettle, oven and radiators (3.3 kW is not a lot). Now we have learned not to run too much at the same time. Dishes can wait!

[marioreid]

try 2.2!! Does the upgrade really work? I've heard they only change a fuse for a larger one! Does it not come down to how much you have on a one time on that circuit? just wondering, obviously something I should have done long ago, but you know how it is here, you get used to living with it.
REgards
Mario

[El Cid]

Does the upgrade really work? I've heard they only change a fuse for a larger one! Does it not come down to how much you have on a one time on that circuit?

Yes, they merely change the fuse as I said earlier. If you exceed your contracted supply for more than a few minutes, the fuse heats up and trips. A larger fuse will allow more appliances to be on at the same time before it trips.

Sid

[marioreid]

Many thanks Sid
REgards
Mario

[spanish_lad]

That interesting Sid. I have a 3 phase input but only had a 3.3 kW rating until I suffered a fire in the "fusebox" and when the electrician fitted a new box and cables he said that he had upgraded the connection to 5.5

no, you actually had 9.9kw, and now you have 16.5 kw work that one out

[Don]

Interestinger and interestinger SL. Before the fire and the "upgrade" which was indeed just a larger fuse, I could easily trip out with 4 appliances around the 1 kW mark. Now it still trips if too much is on but far more manageable. Are you saying that the limit of 3.3 or 5.5 is per split of the 3 phase ? Yeah, I am trying to work this out now ! Could it be that the trip at an apparent 5.5 kW is actually due to all the appliances being on the same phase split and I could avoid tripping by putting some appliances into another circuit on a different phase split ?

3-phase has always confused me.

[El Cid]

3-phase has always confused me.

Me too!

Just to add further confusion, we have a 15kw 3 phase supply with no potencia trip at all and our contracted potencia is 4.93kw!

Sid

[spanish_lad]

right.

single phase: one supply at 240v +/- (normally around 228v) you get a live and a nuetral into your house. mostly only the live will go thru the single icp (the breaker on its own, to the left of the consumer unit), and then into the consumer unit.

with 3 phase:

you have THREE 240v supplies at 240v (228v etc), all going thru a long 4 way icp, so the three lives AND the neutral go through it. then they all go into the consumer unit.

this is where it gets confusing - each supply feeds a "bank" of breakers, and the neutral is split between them, but seperated by the rcd.


its alot harder to explain than to "do" lol - i could wire a consumer unit blindfold almost. this is why electricians cost so much its not just wires, it takes alot of working out lol


when we wire a house from scratch and it has a 3 phase supply we will always split the 3 phases, one for aircon, one for the kitchen and one for the rest of the sockets then the lights for the house spread between all three phases so that at least some lights will be on if one rcd trips out .. depends on the things in the house but generally the "high consumption areas (aircon, cooker, pool etc) will be seperated, so you hardly ever get it over loading.

so when i said "no, you actually had 9.9kw, and now you have 16.5 kw work that one out " it means that yes, you had 3.3kw per phase, so you could load 4kw onto one phase and the RCD would trip. you'd have to load around 20kw all at the same time to trip the main icp tho.

your "potencia contractada" is defined by the main icp inside the house, so it will probably be 40a / 63a etc. you dont normally see anything higher than that. if you increase your potencia contractada all they do is come along and change your icp and sometimes the fuse/s in the meter box outside, depending on their size.

[hillybilly]

i could wire a consumer unit blindfold

I thought that was the way you always worked?

[Cassandra]

So how do you upgrade? Just phone the lovely Sevillana and ask them? We could run Blackpool Illuminations from our kitchen but the power trips if we use a 2.5kw heater in any other part of the house and have to turn it to low if we want a heater on in the bedroom as well as the lounge

[spanish_lad]

if you wern't older than me hilly i'd spank ur ass :p hahahaha ... blindfolded obviously

[spanish_lad]

So how do you upgrade? Just phone the lovely Sevillana and ask them? We could run Blackpool Illuminations from our kitchen but the power trips if we use a 2.5kw heater in any other part of the house and have to turn it to low if we want a heater on in the bedroom as well as the lounge

the main icp? on the left, seperate from the consumer unit? or an rcd, one of the ones with the test buttons on it? how many rcds do you have? how many breakers in your box?

if its an old house with only a few breakers it would probably benifit from a rewire, you are looking at thousands of euros.

sevilliana will not upgrade your ICP if your bullatin is over 4 years old, but you cant get a bullatin unless it is up to modern specs. so to get a bullatin you need a rewire, and to get an upgrade you need a bullatin ...

[Cassandra]

Oh well, spanish central heating for me then I'll get down to the market tomorrow and buy one of those fleecy robes their so fond of

[El Cid]

when we wire a house from scratch and it has a 3 phase supply we will always split the 3 phases, one for aircon, one for the kitchen and one for the rest of the sockets then the lights for the house spread between all three phases so that at least some lights will be on if one rcd trips out .. depends on the things in the house but generally the "high consumption areas (aircon, cooker, pool etc) will be seperated, so you hardly ever get it over loading. .

Thanks for that Spanish Lad - it is getting a bit clearer now.

Presumably you cannot tell how the phases were wired without looking in the back of the panel. We have 3 seperate panels, one for the house, one for the garage/almacen and one for the pump room - I assume that they are probably each on a different phase.

We have a night tarif and as I understand it, there will not be an ICP - we certainly don't have one - there is a big gap in the panel where it would be. What we do have is three big fuses on each phase in the meter box outside going into the night meter - are these the equivalent of an ICP? If so, what happens if we overload - do they have to be replaced?

The reason we have a 3 phase/15kw supply is because we have underfloor heating which (in theory) can take 17kw if we can afford to switch it all on. We have tried running the whole system but apart from the wheel in the meter reaching about 10000rpm, nothing tripped!

You also said "you had 3.3kw per phase, so you could load 4kw onto one phase and the RCD would trip" - I thought RCD's only tripped if there was a problem rather than a "contractual" overload - isn't that what the ICP is for?

Still (less) confused.

Sid

[Lavanda]

Thanks everyone, especially Spanish_Lad. Think I'll ask for an upgrade just to be 'safe'.

[spanish_lad]

Thanks for that Spanish Lad - it is getting a bit clearer now.

Presumably you cannot tell how the phases were wired without looking in the back of the panel. We have 3 seperate panels, one for the house, one for the garage/almacen and one for the pump room - I assume that they are probably each on a different phase.

quite right, its impossible to tell without me actually looking at the house. you can tell yourself by plugging in a lamp and turning off each breaker in turn to see what gives power to where.

although.. when you say "3 seperate panels" .. i assume you mean three consumer units ? (box with a door on and loads of breakers inside?) chances are they will all be linked and not run independantly because the neutral is only one "line" and therefore would have to be "split" somewhere. i'd assume that power goes to the "main" consumer unit and then is divided from there, i'd bet there is a breaker in your "main" unit that shuts off the power to the other two? probably two independant breakers.

We have a night tarif and as I understand it, there will not be an ICP - we certainly don't have one - there is a big gap in the panel where it would be. What we do have is three big fuses on each phase in the meter box outside going into the night meter - are these the equivalent of an ICP? If so, what happens if we overload - do they have to be replaced?

theres two different "problems" here. the night tarif (old style) is run by a second electricity meter in a double sized box on the perimiter of your property, and nothing to do with anything else, both meters are linked, and two readings are present, one for the day and one for the night.
the "newer" style meters are digitised and a property only needs one meter to switch between tariffs, its a digital display with two readings on it. this is run by a thin red wire going to your consumer unit that goes to a timer.

the second "problem" is your lack of ICP - this is nothing to do with anything apart from lazy workers you were probably not in when they came to fit it, and they never came back and wrote it up anyways. your "input" of power will go directly to your first main breaker. the icp is basically an "overload" protection breaker, and is fitted by sevilliana. your first "main" breaker is "acting" as your icp. this is not a problem, and i wouldn't tell anyone. the amount of houses that we visit that dont have them is unreal. dont worry about it.
the three fuses, they are one per phase (muchio sparkio if anything is plugged in and you take them out ) if these blow then yes, they need replacing. they are only a few euros each, but if an electrician were to come and do it for you they would charge call out + some as it it live power. this is very rare and i've only had to do two or three in 8 years after thunder storms.

The reason we have a 3 phase/15kw supply is because we have underfloor heating which (in theory) can take 17kw if we can afford to switch it all on. We have tried running the whole system but apart from the wheel in the meter reaching about 10000rpm, nothing tripped!

you have 17,000w underfloor heating?? is it water or electrical ? if its water its going to be nothing near that, but if it is electrical thats a huge amount of power refer to previous answer as to why it hasn't tripped even tho you are only contracted 15kw, 17kw is obviously alot lower than the main fuses that you have in your meter box outside, and it must be powered in such a way that the main breaker isn't overloaded. i must say i've never heard of a 17kw underfloor heater, i'll check it out with the boss tomorrow.

You also said "you had 3.3kw per phase, so you could load 4kw onto one phase and the RCD would trip" - I thought RCD's only tripped if there was a problem rather than a "contractual" overload - isn't that what the ICP is for?

got me on that one i messed up there, the individual breakers after the rcd would trip (one would trip, depending on the over loaded circuit)... my bad i was confusing myself the icp does trip if over loaded, as would the main breaker, i would expect either of the two to trip due to overload, depends on which has a faster reaction time.


hopefully that clears up a few things?

legal disclaimer: i take no responsibility if you (or anyone reading) messes with their electrics on the strength of my advice.

[spanish_lad]

Thanks everyone, especially Spanish_Lad. Think I'll ask for an upgrade just to be 'safe'.

are you sure? remember what i said earlier...

how many rcds do you have? how many breakers in your box? do you have an anti surge unit in your consumer unit? is your incoming cable "green" on the outside?

if its an old house with only a few breakers it would probably benifit from a rewire, you are looking at thousands of euros.

sevilliana will not upgrade your ICP if your bullatin is over 4 years old, but you cant get a bullatin unless it is up to modern specs. so to get a bullatin you need a rewire, and to get an upgrade you need a bullatin ...