[OT} Electricity usage

[The Natural Philosopher]

multiply by 240..

and get 1.456kw or in an hour 1.456kWh...

[fred]

In article , News writes

Something doesn't look quite right in that bottom picture.

To the left of the meter there is what looks like the supplier's fuse with the main (thick red) feed coming in at the top but there appears to be another thinner red connection wire daisy chaining into the unprotected side of the fuse.

If it really is connected at that point then it doesn't look right at all. As it is on the supplier's side then it wont be an answer to your metering problem but running an unprotected spur in undersize cable looks decidedly dodgy.

Maybe see if you can find where that goes, the shop perhaps?

Anyway, back to the metering, if you apply the clamp to the big red wire and the spur is as it looks then you will be measuring any current going off in that limb too. You would be better applying the clamp to wire 1 going into the meter. Actually, there's more slack on the neutral (wire

2) so that would be easier and the sensor doesn't care which side it's on.

[fred]

In article , Robin writes

I did nearly ask if that was what the shop sold ;-)

[Tim Streater]

watts = volts x amps

So you have 6.07 x 240 = 1457W = 1.457kW

units = kWh = kW x hours

So 1.457 units after one hour.

Obviously, current draw varies over time. The unit I got at Amazon and posted a link to measures the kWh draw (as does your electric meter).

[Andy Burns]

Well yes, no point measuring the current to 1/100th of an Amp, then having to guess the voltage to the nearest 10 Volts.

[News]

In message , fred writes

Perfect. Thank you.

Back to that daisy chained cable, then yes, the shop is very likely. At one time, pre shop, there was a room off the kitchen, which was extended to the pavement, to create the shop. At least 30 years ago. Logic suggests the original room would have had power fed from the house supply, but house and shop would have been separated when the shop was created.

Our supply is overhead cable, and there is only one cable, which suggests the one supply terminates in my (house) cupboard with the shop supply being taken pre meter, as suggested. The loft is full of cables, mains, telephone and Heaven knows what else. Although house and shop have separate phone lines, there are various shop line phone sockets in the house, and a repeater bell, all from pre cordless days. No, I don't plug my home phone into the shop's line :-)

There is also what looks to be the remains of a butler bell system up there.

[Chris J Dixon]

Well, as long as the supply isn't interrupted you can get total hours elapsed and total kW used.

Chris

[Richard]

I have one of these:

Quite handy.

[News]

In message , fred writes

The shop was (and remains) a post office, without any form of 'pot' plant for sale :-)

[spuorgelgoog]

That's probably your neighbour's supply.

Use one of the two cables going from the bottom of the black main fuse into your meter.

Owain

[News]

In message , Tim Streater writes

Now that looks useful, thanks. Time to establish exactly was is 'on' first, and that the meter is correctly recording usage. This morning's plans have been put on hold, due to activity in the kitchen. Been busy grating and juicing oranges and lemons :-)

[fred]

In article , News writes

I'll explain what my concerns are over that spur so you are aware of the risks.

The main incomer looks to be about 16mm2 and is meant to go straight the main fuse (80A?) with minimal length, and nowhere else. The reason for that is that it is totally unprotected so physical damage resulting in a short could cause very serious damage or a fire. That said, any short applied across a 16mm incomer would likely disappear on its own in short order as it vaporised, the fault current being so high (even on an overhead).

Once it passes through the main fuse it becomes a protected circuit (reduced risk) and it passes to the various consumer units (sorry fuse boxes :-) that you have. Even then, the length of the cables passing to fuse boxes are meant to be limited in length (usually 3m unless further protected by a separate switch and fuse (switchfuse) again to limit risk in case of physical damage.

That spur however looks only to be about 4 or 6mm2 and obviously has a far lower current capacity than the 16mm one. It is also on the unprotected side of the main fuse and so is exposed to very high fault currents if damaged. The risk is that if a big nail was put through it at the shop end then there is no fuse to protect it but the cable may not be big enough to carry enough current to wipe out the nail that causes the short. The risk is that the length of the smaller cable will rapidly (instantaneously) overheat and set fire to anything flammable it is in contact with. Also, there is nothing you can do about it as there is no fuse to blow and no way of disconnecting the fault. Also, as it is a smaller cable, people may not understand its significance or how dangerous damage to it could be.

Aside: Well Adam did I get any of that right?

[js.b1]

Some of those meter tails look like single core, not insulated sheathed (61

81Y).

Check fridge/freezers to see if the compressors have burnt their paint off:

- Thermostats can stick on - compressor runs 24/7

- Insulation has shifted, saturated with ice - compressor runs 24/7

Stick all the IT gear on an energy monitor.

- Processors such as P4 Prescott suck energy like the 2 legged version

- Likewise early Plasma could draw 400-680W depending on size

You say turning the power off did not stop the shop, well maybe. Is there any link in the LOFT between the lighting circuits? Is there any link on any power sockets?

UK average is circa 10 units a day, even with tumble-dryer 1.5hr & washer e very day on 40-60oC wash & electric cooker & electric immersion (light usag e) & fridge & freezer (2 compressors).

A laptop is 10-30W, a PC can be 180-300W, so it may be economic to switch t o a lower energy processor "modern" machine (IT stuff is peanuts on Ebay), or go to laptops (plenty of ex lease for peanuts on Ebay).

Your annual energy consumption is close to a 3-bed semi PEAK *and* E7-NSH c ombined kWhr. That is with electric heating appliances for 120 days of the year, per day summer is 9 units, winter is 25-35 units and exceptionally co ld spell can be 40-50 units. You are running 25 units which is mostly over

17hrs.

[John Rumm]

Not on that circuit... there may me one non maintained emergency light on each - but the load seems too high for that. Perhaps I ought to measure the leakage through the touch dimmers.

[Andy Burns]

Surely you'd notice 96W warming up a few dimmer switches if it was happening ?

[John Rumm]

More than likely (I expect their quiescent load to be down in the uA TBH) - just struggling to think of what else could be on the circuits. No extractor fans etc

[Andy Burns]

PIRs or dusk/dawn sensors?

[John Rumm]

Re: touch dimmers - as expected, too low to register on the clamp meter.

One PIR on that circuit - just tested that - again below the resolution of the meter...

(and the particularly odd thing is the load on *both* downstairs circuits, where there are very few light fittings on one)

[Andy Burns]

a pair of charred rat jaws?

[News]

In message , fred writes

OK, read and understood. Thanks. As you say, it must have been installed like that by the power company. I shouldn't go into the back of the shop (leased to someone else) but I will, just to see what the incoming mains leads look like at that end.

Been outside with binoculars. A support cable from the pole on the pavement attached to an insulator bolted to my chimney stack. Two incoming cables wrapped around the support cable. Those two cables amalgamate my side of the insulator and disappear into a metal conduit which goes through the roof into the loft, fairly close to the main fuse and consumer units (OK, not fuse boxes ).

That too is close to where the shop attaches to the house. The only test I can really do re house/shop is turn off the power in the house on a Sunday, then go into the shop and make sure all the lights and sockets are live. Any dead will be cause for concern.