Monaco Cayman 2005 Owner's Manual page 274

If the generator is running, 120 Volt AC will be present at the distribution panel L1 (Line 1) and L2
(Line 2) inputs. In this mode the energy management feature is disabled and all control relay contacts are
closed, energizing all of the controlled loads. The control module sends a signal to the display panel caus-
ing the load meter to display actual load current, the GEN SET service indicator to light and all power
status indicators to light.
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.
The load meter will indicate the Amp's Load. 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 the shedding table, again calculating the amount of current that was removed and placing this
value in memory. The system continues to turn off loads until the total current falls below shore
power amperage 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 manage-
ment 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 cur-
rent 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 on the
display panel will illuminate.
274
Section 8 --- Electrical Systems - House
Cayman 2005