START-UP
Unit Preparation Ð Make sure that unit has been in- stalled in accordance with these installation instructions and applicable codes. Make sure that
Compressor Mounting Ð Compressors are inter- nally spring mounted. Do not loosen or remove compressor holddown bolts. On 48TJ014 units, remove the tiedown bands that hold the compressors together.
Internal Wiring Ð Check all electrical connections in unit control boxes. Tighten as required.
Refrigerant Service Ports Ð Each refrigerant sys- tem has 4
Compressor Rotation Ð On
1.Connect service gages to suction and discharge pressure ®ttings.
2.Energize the compressor.
3.The suction pressure should drop and the discharge pres- sure should rise, as is normal on any
If the suction pressure does not drop and the discharge pressure does not rise to normal levels:
1.Note that the evaporator fan is probably also rotating in the wrong direction.
2.Turn off power to the unit.
3.Reverse any two of the unit power leads.
4.Reapply power to the compressor.
The suction and discharge pressure levels should now move to their normal
NOTE: When the compressor is rotating in the wrong direction, the unit will make an elevated level of noise and will not provide cooling.
Cooling Ð To start unit, turn on main power supply. Set system selector switch at COOL position and fan switch at AUTO. position. Adjust thermostat to a setting below room temperature. Compressor starts on closure of contactor.
Check unit charge. Refer to Service, Refrigerant Charge section, page 26.
Reset thermostat at a position above room temperature. Compressor will shut off. Evaporator fan will shut off after
TO SHUT OFF UNIT Ð Set system selector switch at OFF position. Resetting thermostat at a position above room tem- perature shuts unit off temporarily until space temperature exceeds thermostat setting.
Main Burners Ð Main burners are factory set and should require no adjustment.
TO CHECK ignition of main burners and heating controls, move thermostat set point above room temperature and verify that the burners light and evaporator fan is energized. After ensuring that the unit continues to heat the building, lower the thermostat setting below the room temperature and verify that the burners and evaporator fan turn off (fan will turn off only if fan selector switch is in the AUTO. position). Refer to Table 15 for the correct ori®ce to use at high altitudes.
NOTE: Upon a call for heat, the main burners will remain on for a minimum of 60 seconds.
Heating
1.Purge gas supply line of air by opening union ahead of gas valve. When gas odor is detected, tighten union and wait 5 minutes before proceeding.
2.Turn on electrical supply and open manual gas valve.
3.Set system switch selector at HEAT position and fan switch at AUTO. or ON position. Set heating temperature lever above room temperature.
4.The
5.After a call for heating, the main burners should light within 5 seconds. If the burners do not light, then there is a
6.The
7.The
8.Adjust air¯ow to obtain a temperature rise within the range speci®ed on the unit nameplate and in Table 1.
NOTE: The default value for the
When one ¯ash of the LED
The
To restore the original default value, reset the power to the unit.
TO SHUT OFF UNIT Ð Set system selector switch at OFF position. Resetting heating selector lever below room tem- perature will shut unit off temporarily until space tempera- ture falls below thermostat setting.
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