Bryant 551B, 551C Make Electrical Connections, Field Power Supply, Field Control Wiring

551B,C

Step 5 —Make Electrical Connections

!WARNING

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury or death.

Unit cabinet must have an uninterrupted, unbroken electrical ground to minimize the possibility of personal injury if an electrical fault should occur. This ground may consist of electrical wire connected to unit ground lug in control compartment, or conduit approved for electrical ground when installed in accordance with NEC (National Electrical Code), ANSI/NFPA (National Fire Protection Association), latest edition, and local electrical codes. Do not use gas piping as an electrical ground.

Field Power Supply

All units except 208/230-v units are factory wired for the voltage shown on the nameplate. If the 208/230-v unit is to be connected to a 208-v power supply, the transformer must be rewired by disconnecting the black wire from the 230-v 1/4-in. terminal on the transformer and connecting it to the 200-v 1/4-in. terminal from the transformer.

Refer to unit label diagram for additional information. Pigtails are provided for field service. Use factory-supplied splices or UL (Underwriters’ Laboratories) approved copper connector.

When installing units, provide a disconnect per NEC.

Field Control Wiring

Install a Bryant-approved accessory thermostat assembly according to installation instructions included with the accessory. Locate thermostat assembly on a solid wall in the conditioned space to sense average temperature in accordance with thermostat installation instructions.

Route thermostat cable or equivalent single leads of colored wire from subbase terminals through connector on unit to low-voltage connections (shown in Fig. 10).

NOTE: For wire runs up to 50 ft, use no. 18 AWG (American Wire Gauge) insulated wire (35_C minimum). For 50 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 wires larger than no. 18 AWG cannot be directly connected to the thermostat and will require a junction box and splice at the thermostat.

1.Connect thermostat wires to screw terminals of low voltage terminal board.

2.Pass the control wires through the hole provided in the control box.

3.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.

Heat Anticipator Settings

Set heat anticipator settings at 0.8 amp for first stage and 0.3 for second stage heating.

All field wiring must comply with NEC and local requirements.

Install field wiring as follows:

1.Install conduit through side panel openings. For units without electric heat, install conduit between disconnect and control box.

2.Install power lines to terminal connections as shown in Fig. 12.

3.For units with electric heat, refer to Accessory Electric Heat Installation Instructions.

During operation, voltage to compressor terminals must be within range indicated on unit nameplate (also see Table 3 and 4). On

COOL STAGE 1	Y1/W2
FAN	G
HEAT STAGE 1	W/W1
COOL STAGE 2	Y/Y2
HEAT STAGE 2	O/W2
24 VAC HOT	R
24 VAC COM	C
N/A
OUTDOOR AIR	S1
SENSOR	S2

THERMOSTAT DIPSWITCH SETTINGS

ON

OFF

A B C D

LEGEND

Field Wiring

R
G
Y1	WIRE
Y2
	CONNECTIONS
W1	TO
	LOW-VOLTAGE
W2	SECTION
C
IPD/X

3-phase units, voltages between phases must be balanced within 2% and the current within 10%. Use the formula shown in Table 3 and 4, Note 2, to determine the percentage of voltage imbalance. Operation on improper line voltage or excessive phase imbalance constitutes abuse and may cause damage to electrical components. Such operation invalidates any applicable Bryant warranty.

NOTE: If accessory thru-the-bottom connections and roof curb are used, refer to the Thru-the-Bottom Accessory Installation Instructions for information on wiring the unit.

NOTE: Underlined letter indicates active thermostat output when configured for A/C operation.

C06008

Fig. 10 ---Low-Voltage Connections With or Without Economizer or Two-Position Damper

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