34
CONTROLS
Setting Jumper Links
Jumper links are located on the microprocessor controller
PCB to offer different control features and their functionality is
listed below:
Jumper link settings must be made with the power turned
off and PCB battery removed. Jumper link 1 will be factory set
to ON, jumper link 2 will be factory set to OFF. Jumper link 3
will be factory set to ON, should a master/slave system be re-
quired, jumper link 3 will require setting during the start-up of
the units.
Software Control —
The control system software per-
forms the following primary functions:
• Control of the indoor fan and electric heater to achieve
and maintain the temperature set point.
• Monitor status and temperature inputs for error condi-
tions and shut down the relevant outputs in the event of a
fault occurring.
• Communicate with other controllers when operating in a
master/slave setup.
• Receive coded IR data from the hand held IR transmitter
or optional pendant and adjust control parameters as
instructed.
• Operate to time functions if they are required.
Main Control Functions
INDOOR FAN OPERATION — The indoor fan will run
continuously at the most recently set speed or will alter the
speed according to the room temperature conditions when set
to Auto mode. The indoor fan will continue to run until the unit
is turned off by the user or via a pre-set time setting. When the
unit is turned off during heating, the indoor fan will continue to
run for approximately 2 minutes; this helps to dissipate residual
heat from the electric heaters.
BOOST HEAT — The electric heat relay can be used to initi-
ate either low watts density electric heating (option) or low
pressure hot water heating (option). The boost heat will be
activated when the room temperature falls to more than 8º F
below set point. Hysteresis of 2º F will be applied to prevent
"hunting." The boost heat facility is automatically enabled/
disabled by selecting non heat pump (jumper 2 open).
TEMPERATURE CONTROL — The controller will switch
heating or cooling loads in order to maintain the temperature
set point. The deadband is programmed to 4 F. Under normal
operation, cooling or heating will be activated at the limits of
the deadband and will continue to operate until set point is
achieved.
The temperature set point can be adjusted between 58 F and
90 F in 2º F increments.
POWER FAILURE — The controller will auto restart in its
previous mode of operation after a power failure, e.g., if the
controller was turned on before power fail, after power is re-
stored the controller will automatically turn on. Alternatively, if
the controller was turned off before power fail after power is
restored, the controller will remain off.
BATTERY BACKUP — To maintain all the user and time
clock settings during a power off situation, a 10-year battery
backup has been provided. This assumes normal power outag-
es. With no power the battery will last up to three months.
When the battery requires replacing, the cool and heat status
LEDs on the IR receiver will flash at 1-second intervals.
Alarms —
The controller monitors the following alarm
conditions:
• Return air sensor failure
• Indoor coil sensor failure
• Condensate high level
• Battery backup low voltage
ELECTRIC HEATER OVERHEAT PROTECTION — In
the event of an auto reset overheat cutout, the electric heater
will be switched off until the temperature drops sufficiently for
the auto cutout to reset itself. Should the manual reset overheat
cutout operate, the electric heater will be switched off and re-
main off until the reset button on the manual overheat cutout is
pressed. (SWITCH OFF POWER TO UNIT BEFORE
RESETTING.)
HIGH CONDENSATE LEVEL ALARM — On occurrence
of a high condensate level condition, the compressor will stop.
When the high condensate alarm level condition clears, the
compressor will automatically switch back on, providing the
compressor protection delays are not active.
NETWORK OPTION — MICROPROCESSOR
CONTROLLER
Master/Slave Operation —
The network option al-
lows for 1 master unit and up to 19 slave units to be intercon-
nected using a twin twisted pair screened cable to create a
network.
The master/slave operation has been programmed to oper-
ate the units in the following manner:
• When the master unit receives a transmission from the
transmitter, the transmitter settings are provided to all
units on the network.
• Slave units do NOT monitor the return-air temperature
but rely on the master unit to monitor return-air tempera-
ture and make all control decisions. Slave units will
mimic the operation of the master unit and will cool,
heat, switch on, switch off etc., with the master unit.
• At all times, the slave units will follow the usual method
of operation regarding alarms and will act accordingly.
When a master unit experiences an alarm, it will act in
the usual manner while maintaining instruction to slave
units to operate normally. The exception to this is when
the master unit experiences a return air sensor failure.
Due to the fact that it cannot control correctly, the master
unit will instruct the slave units to revert to stand alone
operation.
WARNING
Disconnect power supply before making wiring connec-
tions to prevent electrical shock and equipment damage.
All appliances must be wired strictly in accordance with
wiring diagram furnished with the appliance. Use of any
other wiring diagram could result in a hazard to persons
and property.
CAUTION
Any original factory wiring that requires replacement must
be replaced with wiring material having a temperature rat-
ing of at least 105 C.
Ensure that the supply voltage to the appliance, as
indicated on the serial plate, is not more than 5% over rated
voltage.
JUMPER
LINKS
ON
OFF
JMP1
Reversing valve on in
cooling. (factory)
Reversing valve on in
heating.
JMP2
Heat pump mode (Not
available).
Non heat pump mode/
chilled water.
JMP3
Unit is stand alone/master.
(factory)
Unit is slave.
