Before completing the following checks, turn the unit OFF and lock the main power disconnect switch open.
Failure to disconnect power before servicing could result in death or serious injury. Disconnect all electric power, including remote disconnects before servicing. Follow proper lockout/tagout procedures to ensure the power can not be inadvertently energized. Verify that no power is present with a voltmeter.
Inspect the return air filters. Clean or replace them if necessary. Refer to the unit Service Facts for filter information.
Return Air Smoke Detector Maintenance
Airflow through the unit is affected by the amount of dirt and debris accumulated on the indoor coil and filters.
To insure that airflow through the unit is adequate for proper sampling by the return air smoke detector, complete adherence to the maintenance procedures, including recommended intervals between filter changes, and coil cleaning is required.
For detailed instructions concerning these checks and procedures, refer to the appropriate section(s) of the smoke detector Installation and Maintenance Instructions provided with the literature package for this unit.
Periodic checks and maintenance procedures must be performed on the smoke detector to insure that it will function properly
Condensate Overflow Switch
During maintenance, the switch float (black ring) must be checked to ensure free movement up and down.
With the unit running, check and record the following:
Record this data on an “operator’s maintenance log” like the one shown in Table 19, p. 59. If the operating pressures indicate a refrigerant shortage, measure the system superheat. For guidelines, refer to the “Compressor Start-Up” section.
Important: Do not release refrigerant to the atmosphere! If adding or removing refrigerant is required, the service technician must comply with all federal, state and local laws. Refer to general service bulletin MSCU-SB-1 (latest edition).
Source: Trane (www.trane.com)