background image

FIGURE 3

RUN WIRES THROUGH THE BUSHING

UP TO THE CONTROL PANEL

SCREW

PART #1012-085

OUTDOOR TEMP

SWITCH

PART #910-2058

MIS-4053

Manual 7960-847B
Page 

4 of 8

13. Replace all panels, grilles and covers. This 

completes the installation.

14. Check proper operation of the unit by energizing 

the compressor in cooling mode. The condenser fan 
motor should start and ramp up speed as system 
pressure increases.

Sequence of Operation

Upon initiation, the CMA-38 will apply full voltage to 
the fan motor for the time period selected with the Hard 
Start knob (see Figure 6). Hard start time is adjustable 
from 0.1 to 5 seconds. The hard start ensures correct 

rotation of the condenser fan, even in windy conditions. 
After a hard start, the control reads the temperature/
pressure sensor and the fan speed is adjusted until the 
input temperature/pressure matches the setpoint.
The CMA-38 enables the user to set and adjust the 
pressure to be maintained by the control. The setpoint 
pressure is adjustable from 35-465 psig.

Summary of Contents for CMA-38

Page 1: ...lon Wire Ties 6 7961 312 0338 CMA 38 Unit I D Label Field supplied tools needed Personal protection equipment including gloves and safety glasses 5 16 nut driver 1 2 wrench service port 11 16 wrench L...

Page 2: ...peed control box to the pressure switch as shown in Figure 2 5 Install outdoor temperature switch assembly to the fan shroud and route wires through the bushing and up to the control panel as shown in...

Page 3: ...e Figure 5 page 6 and Figure 6 page 7 for wiring and suggested setpoints 10 Find the purple wire not connected to anything that is tucked in the cable duct see Figure 5 Pull it out and connect it to t...

Page 4: ...Sequence of Operation Upon initiation the CMA 38 will apply full voltage to the fan motor for the time period selected with the Hard Start knob see Figure 6 Hard start time is adjustable from 0 1 to 5...

Page 5: ...E ONE OF THE MIDDLE HEADER STUBS TO ATTACH THE FREEZE STAT TO THE EVAPORATOR COIL FREEZE STAT WIRES RUN DOWN COPPER THROUGH THE GROMMET AND INTO THE CONTROL PANEL WITH THE BLOWER MOTOR WIRES Manual 79...

Page 6: ...FIGURE 5 MIS 4074 MOTOR FROM FAN MODULATING LOW AMBIENT BOX MIS 4074 TRANSFORMER COMPRESSOR CONTACTOR TERMINAL BLOCK CABLE DUCT Manual 7960 847B Page 6 of 8...

Page 7: ...881 A Black Red Yellow Black top 2 pins N O Setting position Set to MIN position Set to MIN position Set to 315 RED BLACK BLACK WHITE BLUE Set jumper to TO PRESSURE TRANSDUCER RED WHITE Manual 7960 84...

Page 8: ...Behind Low Voltage Block 12 Pin Plug Blue on UNITS 3 PHASE Low Ambient W24 Units MONITOR Outdoor Contactor Compressor Terminal Block 2 Control Module Compressor Brown on Black Black Yellow Yellow UNI...

Reviews: