Something wrong here !

[Flyingsparks]

Customer moved into a 4 bed property a couple of months ago and has just had an electricity bill for £500 for one month !

I was called out to find out what was causing such a large bill, and found out that the immersion heater had been left switched on permanently.

During my inspection of the electrical installation I discovered this main isolator.



Apart from the obvious 2.5 cable fused off a 100A fuse to feed a sw spur for the local light, my main concern is the 2 SWA cables that have been used as a sub main to feed the house.

The incoming supply is only single phase but is connected to a 100A service connector and 3 lots of meter tails feed into this switch fuse. The outgoing 3 core SWA cable is then used as a sub main to feed the phase conductor to a 3 phase distribution board in the house.

A further 2 core SWA has been used to take the neutral and earth conductors to the same distribution board.

This obviously does not comply with the regulations as these would in effect be classed as single conductors, & eddy currents could be present in both SWA cables !

Do you think that this could also contribute to the high electricity bills ?

 

[telectrix]

well the immersion heater would not run up £500 in a month

 

[mark1979]

did you check the roofspace for metal halide fittings?

 

[telectrix]

and a funny aroma?

 

[Flyingsparks]

That what I figured, so I started digging deeper.

They have had another electrician fit downlights in 4 rooms about a month ago, but these only add up to about 1800 W total.

I did notice that he had installed a three phase RCD on the 3 single phase conductors feeding the distribution board in the house but obviously did not check the sub main !

 

[mark1979]

maybe he had checked out the crop before starting work?

 

[Flyingsparks]

and a funny aroma?

No unfortunately the only aroma I could smell was the babies nappy

 

[D80]

well the immersion heater would not run up £500 in a month

It could easily cost £2-300 a month or so if always on. Without a doubt it's going to be the biggest problem.

It would be worth getting the clamp meter out and seeing what each circuit is pulling, and also getting everything turned on when doing so.

 

[mark1979]

was it definitely 500 for a month and not a quarter? i had nearly the same thing recently.

 

[Flyingsparks]

It could easily cost £2-300 a month or so if always on. Without a doubt it's going to be the biggest problem.

It would be worth getting the clamp meter out and seeing what each circuit is pulling, and also getting everything turned on when doing so.

The immersion heater is in the bottom of the cylinder in the colder water so it may may be on most of the time.

 

[mark1979]

the immersion would be turning itself off on the stat.

 

[D80]

The immersion heater is in the bottom of the cylinder in the colder water so it may may be on most of the time.

NIE/Power NI rates, so more expensive!
3kw * 17.4p tariff * 24 hours a day * 30 day month
Gives £376 or thereabouts. If on 24/7 it won't run 24/7 though, it will hit temperature and cut out. Its the main problem though. A lot of other things can contribute on top of it (Washing machines, electric hob/oven Electric Shower, halogen downlights, tumbled dryers....

Would be well worth clamping each circuit and seeing what pulls what load. Could sell a few GU 10 Led's, an immersion booster switch plus maybe others and save the customer a fortune in the long run.

 

[Knobhead]

How are the tails connected in to the meter?

 

[mogga]

there have been various theroyes about Immersion heaters leave them on turn them on at specific times arguments were
leave it on the stat will turn it off when water is hot and assuming tank is foam lagged it will stay hot for a good while only turning on when water is drawn hence only heating water used bar "ticking over" every so often keeping tank hot
Against time clock When a bath is run FULL tank requires heating due to latent heat ect ect But I doubt £500 would be from immerser as for that switch fuse SOMETHING is wrong you need to find out what goes where and what else is tapped off IE neighbours house ect

 

[GT1]

How is the house heated..
Gas or Electric..?