Bryant 548D installation instructions VI. Adjust FACTORY-INSTALLED Options

B. Field Control Wiring

Install an approved accessory thermostat assembly accord- ing to installation instructions included with the accessory. Locate thermostat assembly on a solid wall in the condi- tioned space to sense average temperature in accordance with thermostat installation instructions.

Route thermostat cable or equivalent single leads of colored wire from subbase terminals to low-voltage connections on unit (shown in Fig. 8) as described in Steps 1 through 4 below.

NOTE: If using Bryant electronic thermostat, set thermostat configuration for “non-heat pump operation.” The use of the O terminal is not required to energize the reversing valve in this family of products.

NOTE: For wire runs up to 50 ft, use no. 18 AWG (American Wire Gage) insulated wire (35 C minimum). For 51 to 75 ft, use no. 16 AWG insulated wire (35 C minimum). For over 75 ft, use no. 14 AWG insulated wire (35 C minimum). All wire larger than no. 18 AWG cannot be directly connected to the thermostat and will require a junction box and splice at the thermostat.

1.If unit is mounted on roof curb and accessory thru- the-curb service plate connection is used, route wire through connection plate.

2.Pass control wires through the hole provided on unit (see connection D in Connection Sizes table in Fig. 6).

3.Feed wire through the raceway built into the corner post to the 24-v barrier located on the left side of the control box. See Fig. 9. The raceway provides the UL required clearance between the high- and low-voltage wiring.

4.Connect thermostat wires to screw terminals of low- voltage connector (see Fig. 8).

NOTE: If thru-the-bottom power connections are used refer to the accessory installation instructions for information on power wiring. Refer to Fig. 6 for drilling holes in basepan.

C. Defrost Board

The defrost board timer cycle is set to 30 minutes. To change the cycle time, remove the wire from defrost board connected to the 30-minute quick-connect. See Fig. 10. Connect the wire to the 50 or 90 minute quick-connects on the defrost board, depending on the desired defrost time.

D. Heat Anticipator Settings

For units with electric heat, set heat anticipator settings as shown in Table 3.

VI. STEP 6 — ADJUST FACTORY-INSTALLED OPTIONS

A. Disconnect Switch

The optional disconnect switch is non-fused. The switch has the capability of being locked in place for safety purposes. (See Fig. 9.)

B. Optional Durablade Economizer

The optional economizer hood assembly is packaged and shipped in the filter section. Damper blades and control boards are installed at the factory and the economizer is shipped in the vertical discharge position.

NOTE: Horizontal discharge block-off plate is shipped with the air hood package. If unit is to be used for vertical dis- charge application, discard this plate.

Assembly

1.Determine if ventilation air is required in building. If so, determine the minimum amount to be supplied by

each unit and record quantity of ventilation air needed for use in Step 8.

2.Remove filter access panel by raising panel and swinging panel outward. Panel is now disengaged from track and can be removed. No tools are required to remove filter access panel. Remove outdoor-air opening panel. Save panels and screws. See Fig. 11. Remove optional outdoor-air damper hood package from filter section.

3.Assemble outdoor-air hood top and side plates as shown in Fig. 12. Install seal strips on hoop top and sides. Put aside screen retainer and retainer screw for later assembly. Do not attach hood to unit at this time.

LEGEND

AHA — Adjustable Heat Anticipator

CC— Cooling Compensator Field Wiring Factory Wiring

Fig. 8 — Low-Voltage Connections

DISCONNECT

BOARD

DISCONNECT SWITCH (OPTIONAL)

RACEWAY

COMPRESSOR

NO. 2

HOLE IN

END

PANEL

COMPRESSOR NO. 1

Fig. 9 — Typical Field Control Wiring Raceway

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