Holiday Neptune 2004, Руководство пользователя

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Initially, all relay contacts are closed and the total current is monitored. If the
total current should exceed the service limit the system will turn off the first load
in the shedding table and calculate the amount of current that was removed, which
is the value for that load. This value is placed in memory. If the current remains
above the service limit the system will turn off the next load in shedding table,
again calculating the amount of current that was removed and places this value,
which is the value of that load, in memory. The system continues to turn off loads
until the total current falls below the service limit or all of the six controlled loads
have been shed. Through this process, the system has "learned" the amount of
current that each particular load draws. This feature compensates for the differences
in current draw over a range of line voltage and ambient temperature, by re-learning
the load each time it is turned off or "shed."
The 50 Amp Smart EMS now waits until the total current is lower than the
service limit and enough current is available (as compared with the amount in
memory for the last load shed) before turning that load back on. This assures that
there is sufficient current to operate the load.
NOTE: There is a two-minute minimum delay period after a load is
shed before the load will be turned on again to prevent air conditioners
from turning on with a head pressure.
Three Hour Averaging:
The RVIA (Recreational Vehicle Industry Association) in conjunction
with the NEC (National Electrical Council) have established rules
regarding the rating of electrical systems and the use of energy
management systems. One of these rules requires that if any energy
management system is used, the average total load current for the
system over a three hour period be limited to 80% of the service rating.
For that reason the 50 Amp EMS calculates the average running current
for the system and, if it exceeds 80% of the service rating, the EMS
sheds loads to reduce the average current below that limit.
For example: If a system operating under 120 Volt AC, 30 Amp service has
been running at the 30 Amp limit for three hours, the EMS will change its
shedding threshold to 24 Amps and turn off loads until the 24 Amp limit is
attained. If the user selects the 20 Amp service mode this limit will translate to
16 Amps. Because the EMS calculates a running three-hour average, if the average
load current drops below the limit the system will restore power to loads based on
their impact on the limit. If the system is in the averaging mode the decimal point
at the lower right corner of the load meter display on the display panel will
illuminate.
294 • SECTION 8 --- ELECTRICAL SYSTEMS - HOUSE NEPTUNE 2004