Heatcraft Mohave, Installation & Operation Manual, Page: 52 / 76

52
Monitoring and Reviewing Operation Values
Reviewing Operation Values
The Monitor button is used to examine and review the current operating conditions of the
system.
Press MONITOR button. A descriptive abbreviation of the item will appear on the LED. After a
few seconds delay the current value of the item will display. Each time the button is pressed a
different item is displayed.
Monitor Button Items
VALP . . . ..Defrost Regulator Valve percent of opening (0 to 100%)
SUPH . . . ..Superheat (°F) measured at inlet of Suction Accumulator
SucT
. . . ..Suction Temperature (°F) at inlet of Suction Accumulator
SucP
. . . ..Suction Pressure (PSIG/HG) at inlet of Suction Accumulator
SSuc . . . ..Saturated Suction Temperature (°F)
LIQP . . . ..Liquid Pressure measured between CU Receiver and Condenser
AMBT . . . ..Ambient Temperature (°F) measured at condenser coil
AUXT
. . . ..Auxiliary Temperature (°F)
E1DT
. . . ..Evaporator #1 Defrost Termination Temp (°F)
E2DT . . . ..Evaporator #2 Defrost Termination Temp (°F)
ACIN . . . ..Control Board voltage (24VAC nominal)
TMMS . . . ..Current time minutes-seconds
TMHM
. . . ..Current time hours-minutes
CCYC
. . . ..Compressor cycles since midnight
RnTM . . . ..Compressor run time since midnight
DFTM . . . ..Duration of last defrost
ETLD . . . ..Elapsed time since last defrost
RTLD
. . . ..Run time since last defrost
VERS
. . . ..Software version
Force Defrost
To force a ‘defrost’, press the FORCE DEFROST button. The system will pump-down and shut
off the compressor. The system will activate the solenoids required for the ‘pre-defrost’ bypass
operation, and a defrost will commence as described in a later section. The display will show
DEF1
.
Reset Time
Pressing this button will reset the time clock in the microprocessor to zero. At initial power up,
pressing this button will bypass the two minute hold off and the system will start immediately
after a valid ‘T-stat’ signal is recognized. The display will show
DELY.
Force Service
Pressing this button TWICE will cause the system to pump down and the compressor to shut off.
The system will remain off until the CLEAR button is pressed. When the system is initially placed
into
FORCE SERVICE
mode, the display will show
SERV
.
While in ‘Service mode’, individual outputs may be activated by selecting the desired output
circuit and pressing the
ENTER
button. The output circuit is selected by turning the blue knob.
Turning the blue knob completely counter-clockwise selects
EVPF
or evaporator fans.
Forced Output Items
These items are displayed as the blue knob is turned in a clockwise direction. Turning the knob
counter clockwise reverses the order. Pressing ENTER will activate the displayed item.
EVPF
...... Evaporator Fan Contactor
LIQS ...... Liquid Line Solenoid
EVPH ...... Evaporator Pan Heater
FAN4 ...... Condenser Fan #4 Contactor
FAN3 ...... Condenser Fan #3 Contactor
FAN2
...... Condenser Fan #2 Contactor
FAN1 ...... Condenser Fan #1 Contactor
COMP ...... Compressor Contactor
BYPV ...... Bypass Solenoid
SucS ...... Suction Stop Solenoid
DEFS
...... Defrost Solenoid
3WAY ...... 3-Way Valve Solenoid
ALRM ...... Alarm Contacts
VALS ...... Regulator Valve control
EVAC ...... Evacuate System Mode
Pressing
ENTER
when
VALS
is selected causes the number 0 to be displayed. This
represents the percentage of regulator valve opening. Turning the blue knob will increase or
decrease this number until a desired setting is made. Press the
ENTER
button to force the
regulator to change to the desired setting.
CLEAR/TEST Button
Pressing this button ONCE will return the LED display to the default display. With the system
in the
OFF
mode, pressing this button will activate the
TEST
mode. In the
TEST
mode, the controller will activate the outputs one at a time starting with the evaporator fans for
4 seconds per output. The sequencing will continue until the
CLEAR button is pressed again.
Status Indicator Led
A red, four digit, alphanumeric LED on the hot gas control board indicates status,
alarms, and error codes.
LED Display Mode
OFF Off
COOL Cooling
DELY Delay
PMPD
Pump Down
DEF1 Pre-Defrost Bypass
DEF2 Defrost
DEF3 Drain down
FREZ Refreeze
TEST
Test
SERV Service