On May 29, 11:03*pm, "Robert Green"
wrote:
"dpb" wrote in ....
On 5/29/2011 8:59 AM, Home Guy wrote:
harry wrote:
Does a "demand meter" give a more accurate measure of energy
consumption?
(I note that no explicit answer is given for that question)
No. *It's immaterial to the usage; only determines what the appropriate
rate will be.
I wouldn't say it that way. *It's very material in that (as you clarify) it
sets the rate for the usage. *Just nit-picking to make it clear to the OP
that there are two very clearly different factors to consider in business
rates that are different from residential rates. *A power blip that ended up
turning every device on simultaneously (a rare situation - except for X-10
users g) could be an extremely costly event. *Why? *Because peak demand
rates are set by the maximum power ever used during the metering period.
The OP could have easily changed the dynamics of his billing by plugging in
a couple of new space heaters at exactly the wrong time. *That sort of event
could easily explain why the OP finds himself owing a lot more money than
last year even though the kWh used could be virtually identical.
Again, that only will matter if you're actually on a
demand-based billing (which, personally, I would doubt for a small
office-type complex, but wouldn't be impossible).
I've learned (the very hard way) that with posters here from all over the
world, many of the things I thought were customary nation or world-wide are
just local quirks. *(-:
So are you saying that customers with "demand meters" are billed on the
basis of their peak demand - a reading based on only a few minutes worth
of energy usage as seen over an entire billing period?
Yes
How is that a fair or equitable way to bill a customer?
What's "fair" got to do with it? *
"Deserves got nothing to do with it" - Unforgiven
It's owing to the fact that as another already posted, facilities have
to be provided by the utility to handle the peak load; that costs more
so they bill more. *It's also an incentive to the customer to look at
load-leveling techniques aggressively to cut their costs.
Are commercial customers that typically use between 2000 and 3000 kwh of
electricity per month normally considered as candidates for a demand
meter, or are they used for much higher usage customers?
Generally, much higher.
All you'll have to do is look at your bill and you'll know what the
tariff schedule is.
Again, you're looking in the wrong place here, first.
No, I beg to differ. I always feel much more comfortable encountering
service personnel and such knowing as much as I can learn elsewhere. *I
believe the OP has learned a great deal from this thread and could get to
the point where an encounter isn't even necessary. *His bill probably holds
the sad tale of a one time excursion into a higher rate zone that's cost him
big time. *I'll bet he now becomes very aggressive managing his peak load.
I would suggest dropping $25 for a basic Kil-O-Wat plug in meter
http://www.newegg.com/Product/Produc...82E16882715001
to measure the current draw of all his equipment. *Then I'd figure out some
sort of switching interlock or timer system to insure that loads don't all
coincide.
In all likelihood, the "problem" is _NOT_ in the metering but in either
having an unknown or parasitic load, the "reading" not being actual
reading but estimated until the "catch up" real reading at the beginning
of the year or other explainable issue. *The likelihood of your meter
being in error is quite low for the explanation of the usage data you
previously posted.
Which is why I recommend the Kil-O-Watt meter. *You can measure each device
(except hard-wired ones) and get a true reading (wattage or V/A) of its
instantaneous power consumption or the consumption over a period of time.
A clamp meter is a good way to measure the items hardwired to the circuit
panel, but it's pretty lousy for determining wattage or power consumption
over time for stand-alone devices.
-
Bobby G.
@Bobby:
Or the OP could have an an electrician install an emon demon like
RBM suggested in his main service panel and the reading from it
and the amount of electricity the OP is being billed for should always
agree...
http://www.emon.com/index.html
~~ Evan