Circuit Breaker - Monaco 2009 Knight Owner's Manual

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, 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
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 translates to 16 Amps.
Because the EMS calculates a running three
hour average, if the average load current drops
below the limit the system restores 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 illuminates.
Display Panel: The display panel connects
to the distribution panel located in the
bedroom. Six power status LED's indicate
power is applied to those loads. These LED's
are on when the power is applied. The load
meter has a two digit display to indicate the
amount of current actually being drawn by all
the appliances in the motorhome.
Located on System Control Panel
Four service type LED's indicate the
source for 120/240 Volt AC power. Three
of these sources are automatically detected
and indicated by the EMS, namely: Gen Set
Service, 50 Amp Service and 30 Amp Service.
The 20 Amp service mode is not
automatically detected and the operator must
manually select the 20 Amp mode when 20
Amp service is available. The service select
button allows the current threshold to be set
to either 30 Amps or 20 Amps, to match the
incoming service.

Circuit Breaker

The internal configuration of the circuit
breaker is designed to trip when excess
current causes the breaker to heat up. The
trip action of the circuit breaker can occur
within milliseconds due to the speed at which
electricity can travel. Breakers are designed
to operate at a continuous load of 80% of the
breaker's rated capacity.
For example: A breaker with a 20 Amp
rating will operate a continuous 16 Amp load.
This design leaves a small amount of working
capacity within the breaker. When an inductive
load is applied, such as when an electric motor
turns on, the motor starts to spin and current
consumption may momentarily exceed the
rated capacity of the breaker. As the electric
motor comes up to operating speed, the electric
motor's current consumption will decrease.
The AC current load then falls back into the
breaker's rated 80% set point. This electric
principle should be kept in mind when using
anything other than 50 Amp shore service and
using appliances with electric motors, such as
060303b
air conditioners.
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