ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Unexplained Power Consumption

I've been asked to investigate unexplained power consumption in a public house (bar where they sell alcohol). The meter has been checked and found to be ok. The client says there has been an unexplained increase in the amount of units the pub is using.

I thought I would investigate a number of things such as: investigating any earth leakage (although would have to be a serious problem); measure current used by appliances to see if as nameplate; any water heater/chiller thermostat not working etc.

There is an interesting article on artificial power consumption but I can't see a pub having much of a PF problem. http://www.marcspages.co.uk/pq/index.htm

Does anybody have anyone thoughts on the subject.

EDIT
On second thoughts PF could be a problem and worth considering. Air conditioning, discharge lamps etc. will all add up to substantial proportion of the overall power used especially if heating is not electric.

[This message has been edited by TeesdaleSparkUK (edited 02-04-2006).]

For a start, I would investigate all of the refrigeration units in the building. If one (or more) has a bad compressor with stray current leakage problems or is habitually hard-starting, it would bump up power use a bit.

Are there other buildings attached to this one? Shut off circuits and see if any other persons try to find out why thier power went off!!It is possible someone accidently or deliberately tied into the pub's circuits.

If the increase is not too huge, I'd look into the possibility of a forgotten lamp(s)in some storage area being left on.

I once had an unexplained jump...when I replaced a fridge with a newer one. The new one was "auto defrost", which was one reason it required more power.

Any new appliance can use much more than the unit it replaces. In the 'old days,' when you turned something off, it was off. Today, many appliances (such as TV sets and fluo lamps) achieve their "instant on" by actually continually using some juice to keep the electronics 'on'....it may be only a few watts, but watts add up.

So, I would ask if there were any new appliances.

If the water heater is electric, I'd start looking for leaks. That's one way to really ramp up consumption in a hurry.

I'd also check the thermostats if there are any immersion heaters. In domestic systems the usage is normally low enough that you soon notice either a drastic increase in the temperature from the hot faucet, even if not actually hearing the water start to boil.

In a pub, it might go undetected with maybe one or two people just casually thinking that the water seems hotter than normal.

During my summer job we had a lady complaining her meter spun too fast. It immediately stopped spinning as we unplugged her roughly 15 year old refrigerator and freezer in the kitchen...
Besides, she complained of her meter spinning much faster than the neighbour's. Well, her meter was a 480 revolutions per kWh type and the neighbour's was a 75 rev/kWh...

On the up side we found her apartment didn't have a ground (her ex who is claimed to be an engineer just ignored the incoming red wire when he rewired and claimed there was no ground available), the RCD didn't work at all and on top of this the evil genius managed to run all the neutrals instead of the hots through the single pole breakers... after seeing that we wondered what kind of engineer that guy could have been... my guess was computer sciences...

Texas, where I come from, "Engineers" are the guys who drive trains.

You forgot "Domestic" and "Sanitation" engineers.

I would check the thermostats of the fridges. If a thermostat is blocked, the fridge will consume much more.

Still on fridges; Check for "Short Cycling" & "Continuously Running" Compressors.
Some symptoms:
Lack of Refrigerant; Faulty Control; reduced Air flow on Condeser (eg. blocked filters, brocken fan belt.); Blocked Filter/Dryer; High Temp. in refrig. area eg(Doors not shutting properly, damaged door seals.); Themostat controlling at too low a temp; Leaky Compressor Valves;

Now a couple of good ones..... Air Cooled Condeser operating with low Temp. outside air; Evaporator needs de-frosting.
Now you hire a CCTV for this one which nobody admits to!!...LEAVING COOL ROOM & REFRIGERATOR DOORS OPEN...."because I was too busy to close it!!!"

Good luck!