Domestic 3 phase advice

[Octopus]

If the mats really are 20a each do you know if there are contactors involved?

 

[snowhead]

If the mats really are 20a each do you know if there are contractors involved?

Maybe the Contractors fitted some Contactors??

 

[7029 dave]

I would, clamp it,whack all on see the kind of load you are pulling.

 

[davesparks]

I would, clamp it,whack all on see the kind of load you are pulling.

I'd be wary of doing that, if it is a hefty load of underfloor then turning it all on at once might be enough to tip an old 60A fuse over the edge.
I'd switch the underfloor heating on gradually (a good few hours between each) to give diversity a chance to come in to play.

Also there is no point in just measuring the max connected load, as it does not represent the maximum realistic demand. You may still end up thinking you need a bigger supply when you don't.

Clamp meters only give a snapshot of the current demand at a particular point in time, you need to record current over a period of time, a week for example, to really know what is going on.

 

[7029 dave]

But it would be a good identifier. yes no.

 

[Engineer54]

If as you state the house is large then an upgrade to an 80A service fuse should be more than sufficient for the present installation and future additions.

As Dave suggested i'd bring these four UFH mats on gradually, i bet as others here say, that you'll not see 135A or anywhere near it....


BTW what's the total square meterage of UFH mats. Oh and i'm sure the installing electrician left the homeowner with all the details of the systems to register the them for warranty purposes etc!! loll!!

 

[shanky887614]

sorry that guy is a muppet?

having 3 single phase boards each fed by a different phase would be fine

i could say the total load in my house is over 100amps

both showers pull 40 amps and the hob 50 acording to the manufacturer

but i doubt it would get anywhere near that

 

[mark_]

Slightly off point but £6.5k for a three phase supply! Did the client not ask this question before they put in the uf heating to begin with. If there are not cooking with electric I take it there is gas on site so for £6.5k they could have put a wet uf system is with far lower running costs. Sounds odd to me.

 

[SIIVION]

Hopefully there are bills/receipts for the underfloor heating somewhere? Or a contact number for the installers?

With a quick bit of research I am sure you will find the loading.
ie. An average sized room of say 20m² X a few examples found via google at 200w/m²

 

[davesparks]

Why guess it when a quick resistance measurement will give a much better idea?