Bryant 127A installation instructions Make Electrical Connections, Compressor Crankcase Heater

Table 2 – Accessory Usage

	REQUIRED FOR LONG LINE	REQUIRED FOR
ACCESSORY		SEA COAST
	APPLICATIONS*	APPLICATIONS
		(Within 2 miles/3.22 km)
Ball Bearing Fan Motor	No	No
Compressor Start Assist Capacitor and Relay	Yes	No
Crankcase Heater	Yes	No
Evaporator Freeze Thermostat	No	No
Hard Shut---Off TXV	Yes	Yes
Liquid Line Solenoid Valve	No	No
Motor Master→ or Low---ambient Pressure Switch	No	No
Support Feet	No	Recommended
Winter Start Control	No	No

*For tubing line sets between 80 and 200 ft. (24.38 and 60.96 m) and/or 35 ft. (10.7 m) vertical differential, refer to Residential Split---System Longline Application Guideline.

{Additional requirement for Low---Ambient Controller (full modulation feature) MotorMasterr Control.

127A

Make Electrical Connections

Be sure field wiring complies with local and national fire, safety, and electrical codes, and voltage to system is within limits shown on unit rating plate. Contact local power company for correction of improper voltage. See unit rating plate for recommended circuit protection device.

NOTE: Operation of unit on improper line voltage constitutes abuse and could affect unit reliability. See unit rating plate. Do not install unit in system where voltage may fluctuate above or below permissible limits.

NOTE: Use copper wire only between disconnect switch and unit.

NOTE: Install branch circuit disconnect of adequate size per NEC to handle unit starting current. Locate disconnect within sight from and readily accessible from unit, per Section 440-14 of NEC.

Route Ground and Power Wires

Remove access panel to gain access to unit wiring. Extend wires from disconnect through power wiring hole provided and into unit control box.

!WARNING

ELECTRICAL SHOCK HAZARD

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

The unit cabinet must have an uninterrupted or unbroken ground to minimize personal injury if an electrical fault should occur. The ground may consist of electrical wire or metal conduit when installed in accordance with existing electrical codes.

Connect Ground and Power Wires

Connect ground wire to ground connection in control box for safety. Connect power wiring to contactor as shown in Fig. 5.

Use No. 18 AWG color-coded, insulated (35_C minimum) wire. If thermostat is located more than 100 ft. (30.48 m) from unit, as measured along the control voltage wires, use No. 16 AWG color-coded wire to avoid excessive voltage drop.

All wiring must be NEC Class 1 and must be separated from incoming power leads.

Use furnace transformer, fan coil transformer, or accessory transformer for control power, 24v/40va minimum.

NOTE: Use of available 24v accessories may exceed the minimum 40va power requirement. Determine total transformer loading and increase the transformer capacity or split the load with an accessory transformer as required.

Final Wiring Check

IMPORTANT: Check factory wiring and field wire connections to ensure terminations are secured properly. Check wire routing to ensure wires are not in contact with tubing, sheet metal, etc.

Compressor Crankcase Heater

When equipped with a crankcase heater, furnish power to heater a minimum of 24 hr before starting unit. To furnish power to heater only, set thermostat to OFF and close electrical disconnect to outdoor unit.

A crankcase heater is required if refrigerant tubing is longer than 80 ft. (24.38 m). Refer to the Application Guideline and Service Manual Longline Section-Residential Split-System Air Conditioners and Heat Pumps.

Airflow Selections (ECM Furnaces)

The ECM Furnaces provide blower operation to match the capacities of the compressor during high and low stage cooling operation. Tap selections on the furnace control board enable the installing technician to select the proper airflows for each stage of cooling. Below is a brief summary of the furnace airflow configurations

1. The Y2 call for high stage cooling energizes the “Cool” tap

on the control board. The grey wire from cool tap is connec-

DISCONNECT

PER N.E.C. AND/OR LOCAL CODES

FIELD POWER

WIRING

3 PHASE ONLY

FIELD GROUND

WIRING

CONTACTOR

BLUE

GROUND

LUG

A94025

ted to tap 5 on the motor. Refer to the furnace Product Data

to find the corresponding airflow. If the airflow setting for

high cooling needs to be switched from tap 5 to a different

tap, jumper a connection from the cool tap to the desired tap

so that the Y2 signal is communicated via the cool tap to the

desired speed tap.

2. The Y1 call for low stage cooling energizes the “Fan” tap

on the control board. The red wire from the fan tap is con-

nected to tap 1 on the motor. Refer to the furnace Product

Data to find the corresponding airflow. If the airflow setting

for low cooling needs to be switched from tap 1 to a differ-

Fig. 5 - Line Connections

Connect Control Wiring

Route 24-v control wires through control wiring grommet and connect leads to control wiring (See Fig. 7). Refer to Installation Instructions packaged with thermostat.

ent tap, jumper a connection from the Fan tap to the desired

tap so that the Y1 signal is communicated via the Fan tap to

the desired speed tap. The Y1 setting will also govern the

continuous fan airflow for the furnace.

Refer to the literature for the furnace for further details.

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