Trane 2TWA2, 2TWA0 Compressor Start UP, Operational and Checkout Procedures, Electric Heaters

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In normal operation, the defrost control light will flash once each second. If the light is flashing more than once per second or not at all, refer to the service manual for that unit.

PIN IDENTIFICATION (See Figure 7.)

1.TEST_COMMON (Shorting any of the other pins to this pin causes the function of the other pin to be executed. Leaving this pin open results in the normal mode of operation.)

2.TST = Test (Shorting TEST_COMMON to this pin speeds up all defrost board timings.)

3.FRC_DFT = Forced Defrost (Short TEST_COMMON to this pin for two (2) seconds to initiate a forced defrost. Remove the short after defrost initiates.)

DEFROST CONTROL CHECKOUT

Normal operation requires:

a.LED on board flashing 1 time/second.

b.24V AC between R & B

c.24V AC between Y & B with unit operating

d.Defrost initiation when FRC_DFT pin is shorted to TEST_COMMON pin.

If a defrost control problem is suspected, refer to the service information in control box.

! WARNING

Do NOT connect 24 VAC to T1 (ODS-A) terminal. ODS-A thermistor WILL BE BLOWN.

Installer’s Guide

H. COMPRESSOR START UP

After all electrical wiring is complete, SET THE THERMO-

STAT SYSTEM SWITCH IN THE OFF POSITION SO COMPRESSOR WILL NOT RUN, and apply power by closing the system main disconnect switch. This will activate the compressor sump heat (where used). Do not change the Thermostat System Switch until power has been applied for one (1) hour. Following this procedure will prevent potential compressor overload trip at the initial start-up.

I. OPERATIONAL AND CHECKOUT PROCEDURES

Final phases of this installation are the unit Operational and Checkout Procedures which are found in this instruction on page 8. To obtain proper performance, all units must be operated and charge adjustments made in accordance with procedures found in the Service Facts.

J. ELECTRIC HEATERS

Electric heaters, if used, are to be installed in the air han- dling device according to the instructions accompanying the air handler and the heaters.

K. OUTDOOR THERMOSTAT

An outdoor thermostat TAYSTAT250B may be field installed. For data, see wiring diagram attached to unit and instruction sheet packaged with outdoor thermostat.

L. SEACOAST SALT SHIELD

BAYSEAC001 (Seacoast Kit) is available for application on units installed within one mile of salt water including seacoasts and inland waterways.

TYPICAL FIELD HOOK-UP DIAGRAMS

Notes:

1.Be sure power supply agrees with equipment nameplate.

2.Power wiring and grounding of equipment must comply with local codes.

3.Low voltage wiring to be No. 18 AWG minimum conductor.

4.ODT-B must be set lower than ODT-A.

5.If outdoor thermostats (ODT) are not used, connect W1 to W2 and W3.

6.N/A to programmable thermostat.

LEGEND

FACTORY WIRING

FIELD WIRING

18-BC51D3-2

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Contents FT. Above UNIT-UNRESTRICTED GeneralLocation and Preparation of the Unit Liquid Line Service Valve Installing Refrigerant Lines Accutron Flow Control Valve Basepan TAB RemovalGAS Line Service Valve Service Valve OperationGAS Line Ball Service Valve Defrost Control Fault IdentificationElectrical Connections PIN IdentificationTypical Field HOOK-UP Diagrams Operational and Checkout ProceduresCompressor Start UP Electric HeatersModels Base 2TWA Outline DrawingMounting Hole Location Troubleshooting Chart What to Check Checkout Procedure