Bryant 551B, 551C installation instructions Adjust Factory-Installed Options

Step 6 —Adjust Factory-Installed Options

Perfect Humidity™ Adaptive Dehumidification

System

Perfect Humidity system operation can be controlled by field installation of a Bryant-approved humidistat. (See Fig. 13.)

NOTE: A light commercial Thermidistat™ device (Fig. 14) can be used instead of the humidistat if desired. The Thermidistat device includes a thermostat and a humidistat. The humidistat is normally used in applications where a temperature sensor is already provided.

551B,C

% RELATIVE HUMIDITY

C06358

Fig. 13 ---Accessory Field-Installed Humidistat

C06359

Fig. 14 ---Light Commercial Thermidistat Device

To install the humidistat:

1.Route humidistat cable through hole provided in unit control box.

2.Some models may be equipped with a raceway built into the corner post on the left side of control box (See Fig. 12.) This raceway provides the required clearance between high-voltage and low voltage wiring. For models without a raceway, ensure to provide the NEC required clearance between high-voltage and low-voltage wiring.

3.Use a wire nut to connect humidistat cable into low- voltage wiring as shown in Fig. 15.

To install Thermidistat device:

1.Route Thermidistat cable through hole provided in unit control box.

2.Some models may be equipped with a raceway built into the corner post on the left side of control box (See Fig. 12.) This raceway provides the required clearance between high-voltage and low voltage wiring. For models without a raceway, ensure to provide the NEC required clearance between high-voltage and low-voltage wiring.

3.A field-supplied relay must be installed between the thermidistat and the Perfect Humidity circuit (recommended relay: HN61KK324). (See Fig. 16.) The relay coil is connected between the DEHUM output and C (common) of the unit. The relay controls the Perfect Humidity solenoid valve and must be wired between the Perfect Humidity fuse and the low-pressure switch. Refer to the installation instructions included with the Bryant Light Commercial Thermidistat device for more information.

Disconnect Switch

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

Manual Outdoor Damper

The outdoor-air hood and screen are attached to the basepan at the bottom of the unit for shipping.

Assembly:

1.Determine quantity of ventilation required for building. Record amount for use in Step 8.

2.Remove and save outdoor air opening panel and screws. (See Fig. 17.)

3.Remove evaporator coil access panel. Separate hood and screen from basepan by removing the 4 screws securing them. Save all screws.

4.Replace evaporator coil access panel.

5.Place hood on front of outdoor air opening panel. See Fig. 18 for hood details. Secure top of hood with the 4 screws removed in Step 3. (See Fig. 19.)

6.Remove and save 6 screws (3 on each side) from sides of the manual outdoor-air damper.

7.Align screw holes on hood with screw holes on side of manual outdoor-air damper. (See Fig. 18 and 19.) Secure hood with 6 screws from Step 6.

8.Adjust minimum position setting of the damper blade by adjusting the manual outdoor-air adjustment screws on the front of the damper blade. (See Fig. 17.) Slide blade vertically until it is in the appropriate position determined by Fig. 20. Tighten screws.

9.Remove and save screws currently on sides of hood. Insert screen. Secure screen to hood using the screws. (See Fig. 19.)

Convenience Outlet

An optional convenience outlet provides power for rooftop use. For maintenance personnel safety, the convenience outlet power is off when the unit disconnect is off. Adjacent unit outlets may be used for service tools.

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