MP-3000a Controller
61
•
Controller cycles a single-speed condenser fan
ON for 2 to 30 seconds every 30 seconds
when the Condenser Fan switch is in the FAN
AIR position. The amount of ON time
depends on the condenser coil, ambient and
compressor discharge temperatures.
•
Power limit is active during initial start-up and
pull-down when the unit is cooling at return
air temperatures above -10 C (14 F).
NOTE: When the Condenser Fan switch is
in the WATER position, the condenser fan
does not operate.
Cool
•
After initial start-up and pull-down to 1.0 C
(1.8 F) below setpoint, the controller calls for
the Cool mode whenever the Return air
temperature increases more than 1.0 C (1.8 F)
above setpoint.
•
Compressor must operate for a minimum of 5
minutes after startup.
•
Controller turns ON the Compressor LED
when the compressor is operating.
•
After initial pull-down to setpoint, controller
keeps the In-range LED ON as long as the
return air temperature remains less than 1.5 C
(2.7 F) above setpoint.
Null
•
The controller calls for Null when the Return
Air Temperature decreases more than 1.0 C
(1.8 F) below setpoint.
•
The controller stops the compressor and
condenser fan.
•
The controller also de-energizes (closes) the
liquid line solenoid valve.
•
The evaporator fans continue to operate
(except when Economy mode is ON).
•
Compressor remains OFF for a minimum of 5
minutes.
A.
Cool*
C.
In-Range
D.
Null*
1.
Decreasing Temperature
2.
Setpoint
3.
Increasing Temperature
*If the compressor stops, it must remain OFF for a
minimum of 5 minutes. When the compressor
re-starts, it must stay ON for a minimum of 5 minutes.
Figure 15: Frozen Load Control Sequence
(Setpoints at -10C [14 F] and below)
AJA1415
Summary of Contents for CRR-40 119
Page 4: ......
Page 16: ...Safety Precautions 16...
Page 18: ...Service Guide 18...
Page 20: ...Model Features 20...
Page 32: ...Specifications 32...
Page 120: ...MP 3000a Controller 120...
Page 160: ...Wiring and Schematic Diagrams Index 160...
Page 161: ...161 MPC2000 Wiring Schematic...
Page 162: ...162 MPC2000 High Voltage Wiring Diagram...
Page 163: ...163 MPC2000 Low Voltage Wiring Diagram...
Page 164: ...164 MPC2000 WCC Wiring Schematic...