Still dont know where my power is going - can someone help?

[guydewdney]

Im at my wits end.

generating 1.8kW at the moment - and im using it all. How? Thats not solar - thats hydro - ie 24/7. Solar is on top.

A clamp on meter shows between 6 and 12 amps for the main CU for downstairs, 1.5 for upstairs, and the 3rd unit is (now) switched off completely. Its a big place - I have three main CUs in the house, and 3 slaved outside (garage, workshop, greenhouse) with pumps, chargers etc etc.

How badly does a clamp meter read for compact flourecents? I have a dozen on in the kitchen (it needs it - its a dark big room)? It looks like it has a PF of 0.5 - so my 12 x 7 or 9w lights should look like 100w, but will read 200w - ie less than 1A.

Seriously - does anyone want to come over and give me a 2nd opinion / hand? I have gone through this so many times - I shouldnt have to be sitting in the cold when Im making this much power! To misquote mad max - you can have all the chutney you can carry..... :-) Reasonable expenses / professional fees paid.

[martin W]

the 7.5 amps you quoted being drawn on the downstairs and upstairs c/units (6-12 +1.5) is eating all your 1.8kw up.

Is the problem you don't know where all that power is being used... sorry if I seem a bit dim here.... it's been a long morning already Guy.

Have you got a list of every thing that connected to each circuit on each consumer unit? Do you show what the nominal power demand is for every item.

have you got an export meter to see if you turn a circuit off the demand drops enough to show an export of electricity.

do you know your house dead load (ie at night when everone is asleep what is being consumed)


Next door neighbour connected to one of your consumer units?? - unlikely


you have probably already done all of the above - I can't think of anything else to check

[Pat_]

I'm not familiar with your wiring - maybe you've described it elsewhere. But the first thing I would check is whether the measurement point somehow includes the generated power. The first thing I would do is draw a big diagram showing the overall distribution. But presumably you have a picture in your mind and can eliminate this.

[HalcyonRichard]

Hi,
    Can you get access to all consumer circuits in the consumer unit ? You could check the main input then add up all the individually fused circuits they should add up to the same. If not you could put your meter on one of the consumer units. Then switch on/off circuits one at a time and see they all respond as expected. It may be worth checking your meter on a known load i.e. fan heater or kettle(both mainly resistive) if it's not right for that you know the meters giving funnies.

Good luck


Richard

[Richard Owen]

Wait until everyone's out of the house and you have a couple of spare hours.

Turn everything off including the freezer and fridge. Isolate the outbuildings.

Measure your consumption. That should be zero.

Then start turning things back on and measure the change in consumption until you find the problem.

[Monty]

Fridge Freezers, boiler fan; pumps and heating temp monitoring equip, alarm panels and PIR's that sit quietly drawing 24/7, alarm clock radios and the like, all difficult to live without.

[guydewdney]

done all of the above - still cant work it out. dead load seems to be 500w.... the problem with measuring seems to be that if everything is off, and then slowly switched on again - it all makes sense. then two hours later its all gone mad again.

definately measuring generated only - a) clamp b) computer c) desktop aurora gadget all tally.

havent got an export meter. Its also three phase just to make things more interesting, but all the domestic loads are on one phase (L3).

I can measure each circuit of the main CU as I have extended each fuse wire with a big loop just for this reason. Its bloomin awkward as its 8 feet up above the washing machine. The loads are dynamic, which makes tracing difficult, so I put 10 ammeters (analogue) in the loops - but that didnt work (cheap ammeters blow up too easily)

fridge freezers:-
1 x old upright, full of 2 pigs, bit carp, should replace tbh
1 x new small A or AA rated samsung freezer
1 x new big fridge A or AA samsung
1 x AAA or A++ freezer - massive commercial thing (350lt?), full to the brim with home made stuff

[martin W]

I shouldn't ask this ..... your turbine is on the domestic single phase?   

there... that wasn't so bad


Anyway could it be all the fridges coming on the same time and using more than you generate and hence runing up your electric meter.... anyway you could put them on timers so they are only actually powered sequenially.. 1 on from 10:00 - 10:30 (or 10:20) then the next one for 20-30 minutes, then the next one in sequence.

I am assuming the root of your problem is that whilst you are generating 1800watt, at times (or all the time?) you are exceeding this demand and drawing in power from the grid. Is your electricity meter stopping for a short while, then when a load (or combination) comes on, it starts back up.

I'm sort of thinking of loads suchs as the fridges, freezers, etc which are cyclic and come in and out and thats maybe why your can't tie down where the load is.

Martin

[renewablejohn]

Guy

Sounds like you have a big motor which uses more electric when it heats up. Should be easy to test as you have 3 phases just move 1 motor at a time until you find the culprit. I would suggest starting with your commercial freezer first.

[knighty]

can you not check it when it's using plenty of power.... and then pull each fuse in turn and look for a big drop in power ?

(and cross your fingers while you're doing it that one fuse causes a much bigger drop in power than the others!)

[johnrae]

Not wishing to be impertinent but, how do you know you're generating 1.8kW
First rule of analysis - check your data

[guydewdney]

not impertinant. as stated above, three different measurements tally at 1.8kW - two computers showing the data from the inverters, and a clamp meter on the wire from the inveter to the CU showing about 7 amps (its a very old clamp meter admittedly so might be wrong slightly).

main DNO meter has a light which glows upon export - it isnt glowing.

[johnrae]

If most of your loads are refrigeration compressors using motors they will be giving a highly inductive load.  The current will be lagging the voltage to you are actually measuring VA rather than watts.  It is possible that your refrigeration system data plates show watts which is a what you actually pay for when you buy electricity from the supplier.

The lagging load current will be having an adverse effect upon your generator to the extent that it cannot output its rated 1.8kW (presumably based on a PF of 1.0)

If you can lay your hands on some large mains rated capacitors then fitting these across your compressor motor terminals may actually improve the power factor and effectively reduce your system's reactive load

[HalcyonRichard]

Hi,
    Not sure about your arrangement. But if you have a three phase generator and put different loads on each phase i.e they are not balanced could this cause problems ? I take it you have three phase and neutral arrangement.

Regards Richard

[guydewdney]

Update,

just picked up the post - and the leccy bill is in there:-

20/10/2011 - 13171 reading
20/01/2012 - 15952 reading

2781 units in three months? PLUS what I have generated (ok - the last week has been zero on the hydro) - with 2kw of solar on the phase I am using for the house, plus an average of 2kw constant for the hydro (ie 48kWh per day - ie about 4300kWh)

assuming Im using 90% of the hydro - lets say 3800 units, the solar has made 150 units? (the total for two is about 130 units per month), plus the use of 2781 units on the bill

thats 78 units a day - or basically 3kw 24/7


NOW tell me summit anit wrong.

Big loads:-
2 x washing machines (baby in washable nappies)
2 x 500w heaters on at night, one for baby, one for aupair who cant be educated With thermostats, so not actually on all night
1 x fishtank, 21 degrees C - 2 x 150w heaters
low energy lights everywhere
electric hob (induction) + oven
3 freezers, all full to the brim. 2 uber modern, one old and carp, but has been super insulated ghetto stylee


any ideas