Monaco DIPLOMAT 2004 Owner's Manual page 310

DIPLOMAT 2004
8 •310
If 120 Volt AC is present at the distribution panel L1 and L2 inputs the
system will assume that 120 Volt AC, 30 Amp shore power is available and the
energy management feature will be enabled. If only 20 Amp service is
available the user must select the 20 AMP service mode by momentarily
pressing the 20/30 Amp select switch on the Control Panel. 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, turning the loads off and calculating 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
placing this value, which is the value of that load, in memory. The system con-
tinues 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
3 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 3 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.
ELECTRICAL SYSTEMS - HOUSE