Carrier EK, 48EJ, EW, EY024-048 installation instructions Pressure Transducer Locations

Step 11 Ð Install All Accessories Ð After all the factory-installed options have been adjusted, install all ®eld- installed accessories. Refer to the accessory installation in- structions included with each accessory.

MOTORMASTER III INSTALLATION

Install Field-Fabricated Wind Baffles Ð Wind baffles must be ®eld-fabricated for all units to ensure proper cooling cycle operation at low-ambient temperatures. See Fig. 39 for baffle details. Use 20-gage, galvanized sheet metal, or similar corrosion-resistant metal for baffles. Use ®eld-supplied screws to attach baffles to unit. Screws should be 1¤4-in. diameter and 5¤8-in. long. Holes for wind baffles are pre-punched in the unit sheet metal.

To avoid damage to the refrigerant coils and electrical components, use recommended screw sizes only.

On 48EJ,EK,EW,EY024-034 units, the wind baffles at- tach to ¯anges formed on the outer sheet metal of the unit where the condenser coil tube sheets attach.

On 48EJ,EK,EW,EY038-048 units, the wind baffles at- tach to ¯anges formed on the outer sheet metal of the unit corner post. The other end of the baffle is attached to the center panel between the condenser coil and the indoor sec- tion. Two baffles are required for 48EJ,EK,EW,EY038-048 units.

Install Motormaster III Controls Ð Only one Motormaster III control is required per unit.

Motor Ð The circuit no. 1 (lead compressor) outdoor-fan motor (OFM) will need to be changed out in the ®eld to ac- commodate the Motormaster III accessory. The replacement motor part no. is HD52AK652.

On 48EJ,EK,EW,EY038-048 units, only one OFM will need to be changed out. The no. 1 compressor is located at the left side of the unit looking from the compressor end. The circuit no. 2 OFMs are controlled to shut off at 55 F and turn on at 65 F outdoor-air temperature.

Sensor Ð Install the sensor for thermistor input control in the location shown in Fig. 40A-C. Connect sensor leads to the violet and gray control signal leads on the Motormaster III control.

Signal Selection Switch Ð Remove the cover of the Motor- master III control. Set the switch to accept the thermistor sensor input signal. Set the frequency to match the unit power supply (60 Hz).

Motormaster III Control Ð The recommended mounting lo- cation is in the indoor fan section, mounted on the panel that separates the indoor and outdoor sections. On VAV units, this location is next to the VFD.

Do not route the Motormaster III wiring next to the VFD on VAV units. Use a separate connector through the partition when wiring to the OFM.

Electrical Connections

To avoid possibility of electrical shock and personal in- jury, turn off all power to unit before making electrical connections.

When replacing the OFM, reconnect the black, yellow, and blue wires form the outdoor fan contactor to the black, yel- low, and blue wires of the Motormaster III control. Run new wires from the red, orange, and brown wires to the leads of the new OFM. Connect the green wire from the control to ground.

NOTE: On all 575-v units, 2 transformers (part no. HT01AH851) must be used for each Motormaster III con- trol to lower the supply voltage to the control to 460-v. Trans- formers can be mounted anywhere outside the control box.

VAV Ð Variable Air Volume

Fig. 38 Ð Pressure Transducer Locations

1 BOTH SIDES

18

77.7

0.312 DIA HOLES

61

17.167
BETWEEN
HOLES
(TYPICAL)	CROSS-BREAK

78.7	0.5
4.62

NOTE: All dimensions are in inches. Material: 20 gage galvanized steel or other non-corrosive material.

Fig. 39 Ð Motormaster III Baffle Details

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