Table of Contents
Advertisement
SEQUENCE OF OPERATION
Cooling – Circuit R-Y makes at thermostat, pulling
in compressor contactor and starting the compressor
and outdoor motor. The G (indoor motor) circuit
is automatically completed on any call for cooling
operation or can be energized by manual fan switch on
subbase for constant air circulation.
Heating – A 24V solenoid coil on reversing valve
controls heating cycle operation. Two thermostat
options, one allowing "Auto" changeover from cycle
to cycle and the other constantly energizing solenoid
coil during heating season (thus eliminating pressure
equalization noise except during defrost), are to be
used. On "Auto" option a circuit is completed from
R-W1 and R-Y on each heating "on" cycle, energizing
reversing valve solenoid, pulling in compressor
contactor and starting compressor and outdoor motor.
R-G also makes, starting indoor blower motor. Heat
pump heating cycle now in operation. The second
option has no "Auto" changeover position, but instead
energizes the reversing valve solenoid constantly
whenever the system switch on subbase is placed in
"Heat" position (the "B" terminal being constantly
energized from R). A thermostat demand for heat
completes R-Y circuit, pulling in compressor contactor
and starting compressor and outdoor motor. R-G also
makes, starting indoor blower motor.
NOTE: MENU
JUMPER MUST
BE SET TO "ON"
TO CHANGE ANY
SETTINGS WITH
THE FRONT BUTTONS.
TO LOCK THE CO2
CONTROLLER MOVE
JUMPER TO "OFF" AFTER
IT HAS BEEN CONFIGURED
High/Low Pressure control provides protection for the
compressor. In the event system pressures go above
600 PSI or below 15 PSI in either cooling or heating
mode, the compressor will be stopped. This will
activate the red light located in the control panel. The
lockout circuit will hold compressor off line. When the
system problem is corrected, the unit operation can be
restored by turning the main power supply off and then
back on, or by resetting the room thermostat. The low
pressure control has a bypass to eliminate nuisance
lockout on cold start up.
The bypass timer should be set to 120 seconds. This
is to assure there is no nuisance tripping of the low-
pressure control during start up in heating mode under
cold weather conditions (see Defrost Control Board –
Figure 24.
FIGURE 23
CO
Controller (factory set to 950 ppm)
2
Settings Recommended
RON
COH
PRESS UP AND DOWN
ARROWS TO ENTER
CONFIGURATION MODE
USE ARROWS TO SELECT
SETTING. PUSH MIDDLE
BUTTON TO CHANGE.
CONTROLLER WILL
SHOW SET.
Default
1000
1000
ROF
950
950
DSP
C
CT
UNI
US
US
COL
Not Used
Not Used
TOL
Not Used
TOH
Not Used
See Instrution with Controller
BAR
For High Altitude Installations
CAL
Used for Field Calibration
MIS-3326
Manual 2100-601E
Page
33 of 42
Advertisement
Table of Contents
Troubleshooting
