Bryant 551A operation manual 16, Wind Baffle Details

Install Motormaster® I Controls

Only one Motormaster I control is required per unit. The Motormaster I control must be used in conjunction with the Accessory 0° F Low Ambient Kit (purchased separately). The Motormaster I device controls outdoor fan no. 1 while out- door fans no. 2 and 3 are sequenced off by the Accessory 0° F Low Ambient Kit.

Accessory 0° F Low Ambient Kit — Install the Accessory 0° F Low Ambient Kit per instruction supplied with accessory.

Sensor Assembly — Install the sensor assembly in the loca- tion shown in Fig. 26.

Motor Mount — To ensure proper fan height, replace the existing motor mount with the new motor mount provided with accessory.

Transformer (460-v Units Only) — On 460-volt units a trans- former is required. The transformer is provided with the accessory and must be field-installed.

Motormaster I Control — Recommended mounting location is on the inside of the panel to the left of the control box. The control should be mounted on the inside of the panel, verti- cally, with leads protruding from bottom of extrusion.

B. Motormaster III Control Installation (551A240 Only)

Install Field-Fabricated Wind Baffles

Wind baffles must be field-fabricated for all units to ensure proper cooling cycle operation at low ambient temperatures. See Fig. 25 for baffle details. Use 20-gage, galvanized sheet metal, or similar corrosion-resistant metal for baffles. Use field-supplied screws to attach baffles to unit. Screws should be 1/4-in. diameter and 5/8-in. long. Drill required screw holes for mounting baffles.

CAUTION: To avoid damage to the refrigerant coils and electrical components, use recommended screw sizes only. Use care when drilling holes.

Replace Outdoor Motor

Replace outdoor fan motor no. 1 with motor included in accessory kit. Existing motor is not Motormaster® III compatible.

Install Motormaster III Controls

Only one Motormaster III control is required per unit.

Sensor — Install the sensor for thermistor input control in the location shown in Fig. 26. Connect sensor leads to the purple and grey control signal leads on the Motormaster III control.

Signal Selection Switch — 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 — Recommended mounting location is beneath the control box, mounted to the partition that sep- arates the control box section from the indoor section.

NOTE: Dimensions in ( ) are in mm.

Fig. 25 — Wind Baffle Details

NOTE: If unit power is supplied through the roof curb and basepan of the unit, mount the Motormaster III control on the corner post adjacent to the conduit running from the basepan to the bottom of the control box.

X. STEP 10 — INSTALL HUMIDISTAT FOR OPTIONAL PER- FECT HUMIDITY™ DEHUMIDIFICATION PACKAGE

Perfect Humidity dehumidification package operation can be controlled by field installation of a Bryant-approved humi- distat. To install the humidistat perform the following procedure:

1.Locate humidistat on a solid interior wall in the con- ditioned space. Location should be a well ventilated area to sense average humidity.

2.Route thermostat cable or equivalent single leads of colored wire from humidistat terminals through con- duit in unit to the low voltage connection on the 2-pole terminal strip (TB3) as shown in Fig. 27 and Fig. 28.

—16—