FORM 150.66-CL2 (820)
4
JOHNSON CONTROLS
4. Put the unit into Service Mode and cycle each
condenser fan to ensure proper rotation.
5.
Connect a manifold gauge to system 1 suction and
discharge service valves.
Place the Unit Switch in the control panel to the
“ON” position. As each compressor cycles on,
ensure that the discharge pressure rises and the
suction pressure decreases. If this does not oc-
cur, the compressor being tested is operating in
the reverse direction and must be corrected. After
verifying proper compressor rotation, turn the Unit
Switch to “OFF.”
The chilled liquid setpoint may need to
be temporarily lowered to ensure all
compressors cycle “ON.”
This unit uses scroll compressors
which can only operate in one direc-
tion. Failure to observe this will lead
to compressor failure.
The chilled liquid setpoint may need to
be temporarily lowered to ensure all
compressors cycle “ON”.
CHECKING SUPERHEAT AND SUBCOOLING
The subcooling temperature of each system can be cal-
culated by recording the temperature of the liquid line
at the outlet of the condenser and subtracting it from
the liquid line saturation temperature at the liquid stop
valve (liquid line saturation temp. is converted from a
temperature/pressure chart).
Example:
Liquid line pressure =
328 psig converted to temp. 102°F
minus liquid line temp. - 87°F
Subcooling = 15°F
The subcooling should be adjusted to 15°F at design
conditions.
1.
Record the liquid line pressure and its correspond-
ing temperature, liquid line temperature and sub-
cooling below:
SYS 1
Liq Line Press = _______ psig
Saturated Temp = _______ °F
Liq Line Temp = _______ °F
Subcooling = _______ °F
OPTIONS
Display Language
Sys 1 Switch
Chilled Liquid
* Ambient Control
Local/Remote Mode
Control Mode
Display Units
* Lead/Lag Control
* Fan Control
Manual Override
Current Feedback
** Soft Start
** Unit Type
** Refrigerant Type
** Expansion Valve Type
COOLING SETPOINTS
Cooling Setpoint
Range
EMS-PWM Max. Setpoint
PROGRAM
Discharge Pressure Cutout
Suct. Pressure Cutout
Low Amb. Temp. Cutout
Leaving Liquid Temp. Cutout
Anti-Recycle Time
Fan Control On Pressure
Fan Differential Off Pressure
Total # of Compressors
* Number of Fans/System
* Unit/Sys Voltage
Unit ID
* Sys 1 Superheat Setpoint
TABLE 1 – SETPOINTS ENTRY LIST
* NOT ON ALL MODELS
** VIEWABLE ONLY
