ELECTRICAL SYSTEMS-HOUSE - 8
150
CAYMAN 2007
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 fi rst load in the shedding table
and calculate the amount of current that was
removed. 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 suffi cient 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 on the display
panel will illuminate.
Display Panel:
The display panel connects to the distribution
panel located in the bedroom. Six power status
LEDs indicate power is applied to those loads.
These LEDs 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.
Four service type LEDs 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.
NOTE:
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.
Summary of Contents for CAYMAN 2007
Page 12: ...GENERAL INFORMATION 1 CAYMAN 2007 8 NOTES...
Page 14: ......
Page 16: ......
Page 52: ...DRIVING SAFETY 2 CAYMAN 2007 48 NOTES...
Page 80: ...EXTERIOR INTERIOR CARE 3 CAYMAN 2007 76 NOTES...
Page 100: ...APPLIANCES 4 CAYMAN 2007 96 NOTES...
Page 132: ...WATER SYSTEMS 6 CAYMAN 2007 128 NOTES...
Page 160: ...ELECTRICAL SYSTEMS HOUSE 8 156 CAYMAN 2007 NOTES...
Page 226: ...INDEX 222 CAYMAN 2007 NOTES...
