new instalation of storage heaters

stokeseagle

I have moved to a house in cornwall which has no heating, as there is no gas i have purchased 5x 2.6kw 2x1.7kw & 2x0.85kw storage heaters to heat the home what type of curcuit should i run as i know i cannot spur of the ring main, do i have to run separate cables from the consumer unit to each heater? also will it be an advantage to get a separate meter as there is only one? any help will be gratefully received

Steve

stokeseagle wrote:

I have moved to a house in cornwall which has no heating, as there is no gas i have purchased 5x 2.6kw 2x1.7kw & 2x0.85kw storage heaters to heat the home what type of curcuit should i run as i know i cannot spur of the ring main, do i have to run separate cables from the consumer unit to each heater? also will it be an advantage to get a separate meter as there is only one? any help will be gratefully received

You seem to have made a large comittment (£££'s) to something about which you know very little. Seems slightly foolish to have spent all this money on things you have no knowledge about how to install. Do you have an economy 7 supply? You will probably need a new consumer unit just for the storage heaters, with a 16A radial to each one.

stokeseagle · Posted: Wed Aug 24, 2005 8:19 pm Post Subject:

I have some knowledge of these things oil fired heating was to expensive for installation and running costs, there is no gas where we live so the only alternative was electric also with my discounts i got the right heaters for each room at under £1000. 2x2.6 in the living room,1x2.6 in the hall,1x 2.6 in bedroom 1, 1x 2.6 in bedroom 2, 1x 1.7 in bedroom 3, 1x 1.7 in the kitchen, 1x0.85 in the utiliy room and 1x 0.85 in the bathroom. as of yet the economy 7 supply will be fitted when the heaters are installed. the information for the radial of 16 amp for each heater is good news but what incoming rcd is required?

Spark123 · Posted: Wed Aug 24, 2005 10:56 pm Post Subject:

No RCD is required if your supply is TN-CS/TN-S.
You will need a separate consumer unit on the time switched side of the meter, you need the eleccy board to install an economy7 type meter.
16A radial run in 2.5mm² twin and earth for each of the circuits, Isolation switch (20A DP/FCU) fitted next to each heater with heat resistant flex from the switch to the heater.
These are assuming the cables are not grouped, run in thermal insulation, ambient temp not exceeding 30deg C, using MCBs, and also subject to maximum cable lengths for volt drop.

Just for ban, are you aware that this work is all notifiable under Part P?

Big_Spark · Posted: Wed Aug 24, 2005 11:07 pm Post Subject:

Spark123, are you really having a laugh here?

Just because the smaller Heaters do not need large supplies, they should all be wired in 2.5mm² radial circuits.

These should then be connected to appropriate fused connection units that are fused down to cope with the rating of the attached appliance.

Whether you protected the circuit in the board with 10A or 16A MCB's is a personal choice.

One must always consider what may happen, within reason, to circuits in the future. If he places these heaters in the wrong positions, he may wish to move them around, this would not be possible the way you suggested wiring them.

Further, attaching a 20A DP switch to the end of a circuit wired in 1.5mm² or 1.0mm² is simple crap and the territory of cowboy work IMHO..

I do agree though that this work is Notifiable under Part P.

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I only do commercial and Industrial so Prescott can shove his Part P tax

Spark123 · Posted: Wed Aug 24, 2005 11:18 pm Post Subject:

David E · Posted: Thu Aug 25, 2005 7:50 am Post Subject:

Just a thought. With the heaters just coming on and a draw of approx 80A, what happens when the electric shower/immersion heater or similar kick in. Would this not blow the 100A REC fuse?

Steve · Posted: Thu Aug 25, 2005 6:27 pm Post Subject:

no. . . .

. . . . very unlikely anyway

kai · Posted: Thu Aug 25, 2005 7:49 pm Post Subject: Resistive loads.

The storage heaters and Immersion Heaters are all Resistive type loads, which are very gentle and kind to fuses and MCB's, in respect of power starting surges, so very little problem of nuisance tripping will occur here.

Big_Spark · Posted: Thu Aug 25, 2005 8:11 pm Post Subject: Re: Resistive loads.

kai wrote:

The storage heaters and Immersion Heaters are all Resistive type loads, which are very gentle and kind to fuses and MCB's, in respect of power starting surges, so very little problem of nuisance tripping will occur here.

Absolute ****.

The actual reason the Fuse will not blow is simple...

The storage heaters will be on a Economy 7 meter/clock and as such will only be energised from around midnight to 06:00hrs.

Most people do not shower in these times. However it is possible for the fuse to be overloaded should the shower be used in these hours, however the Main fuse in the service head will require a load of about 130A before it will actually blow, however overloading the fuse will reduce its effectivness to deal with heavy loads in future.

__________________
I only do commercial and Industrial so Prescott can shove his Part P tax

kai · Posted: Thu Aug 25, 2005 9:07 pm Post Subject: Re: Resistive loads.

kai wrote:

The storage heaters and Immersion Heaters are all Resistive type loads, which are very gentle and kind to fuses and MCB's, in respect of power starting surges, so very little problem of nuisance tripping will occur here.

OOPs... I was ambigious here - I meant to say that there will not be a problem of Severe Spikes and surges on the mains supply with the storage heaters coming on.

As FWL was right - you are unlikely to use a shower at the night time off peak hours - unless you work shifts of course!

Big_Spark · Posted: Thu Aug 25, 2005 9:14 pm Post Subject:

That's better Kai, your original choice of words was , as you said, ambiguous at best..out there at worst..

The problem is most people do not understand what Resistive, Inductive and Capacitive loads are and how they effect supplies. Further, even a large number of electricians have forgotten about Resistive Inctance, Capacitive Inductance and Reactive Inductance, and the fact that all of them can be calculated for nearly every type of load that can be attached to electrical circuits, regardless of whether the load is resistive, capacitive or inductive...

__________________
I only do commercial and Industrial so Prescott can shove his Part P tax

Adam_151 · Posted: Thu Aug 25, 2005 9:16 pm Post Subject:

What would be good is a thing that had a coil of wire round one of the tails, and meaured the current clamp meter style, and cut power to a few heaters if it was going to overload the fuse

Big_Spark · Posted: Thu Aug 25, 2005 9:45 pm Post Subject:

Adam_151 wrote:

What would be good is a thing that had a coil of wire round one of the tails, and meaured the current clamp meter style, and cut power to a few heaters if it was going to overload the fuse

It's called "Monitored Line Switching" Adam, and for Industrial plants is used, although not as often in the UK and in other countries. However the equipment is expensive and for 99.99% of domestice installations it is not economically viable.

__________________
I only do commercial and Industrial so Prescott can shove his Part P tax