I don't believe current residential meters even in areas using peak
rates peek at the individual phases, only the total. It's certainly
possible to do so and is at large commercial 3-phase facilities but I
really do not think it is so for residential customers. What
residential peak rate tariffs I know of are actually only based on TOU
rates--time of usage based on peak _system_ usage times, not actually
rate-based metering at the individual meter.
So, I don't think the distribution panel loading balance would/will
make any difference on the total peak usage monitored before the panel
at the external meter. There obviously could be places which go to
this level, but for residential tariff rules w/ which I am familiar
that is not the case.
How do they do that? They don't accelerate the meter during peak
hours, do they? That is, the face of the meter still accurately shows
the watt hours?
Is there a separate counter not shown through the glass that keeps
track of the off-peak (or on-peak) hour use?
I think I now have a radio transmitting meter, so they either have to
drive through the neighborhood, or I'm told maybe they can read the
meter from their office. If the latter, they don't take readings
every time off-peak starts and ends, do they? That would do it but it
Basically, the latter.
TOU meters incorporate a timer and have multiple registers. Residential
variable-rate meters normally only permit two tariffs ("peak" and
"off-peak") and in such installations a simple electromechanical time
switch may be used. The meter will actually have two separate
accumulators only one of which runs at a time--which is selected by the
timer. The meter shows both peak and off-peak usage.
OTOH, large commercial and industrial loads may (do is maybe more
accurate generalization?) use electronic meters which record power
usage in blocks of half an hour or less. These demand-based meters do
record much detail and commercial rates may be predicated on both
time-of-day and system-load as well as the actual load and rate of use
of the premise itself. Many really large industrial users have very
complex load-reduction schemes in place to control their costs by
load-leveling and scheduling.
No, if it is a new enough meter to incorporate remote reading _and_ is
a dual-tariff meter it is probably microprocessor-based and all of the
computations can be easily incorporated in the firmware. In that case
it will have an onboard clock so the TOD and TOU info is readily
available and the accumulation of usage at any given time is simply an
accumulation into one of a particular number of (virtual, software)
accumulators. There are various levels of hybrid (mechancial verus
microprocessor-based) meters, depending on age and manufacturer in use.
Residential meters still outwardly look a lot like the "same old
meter", but likely have at least some cpu-horsepower in them these
days. But, since in most areas residential rates are still one tariff
only, the emphasis has been on the communications and diagnostics to
try to minimize costs to the utility in eliminating meter-readers and
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.