TM 9-4120-411-14
4.5 PRELIMINARY SERVICING AND ADJUSTMENT OF EQUIPMENT.
4.5.1 Check that all ducts are tight and secure. Seal or secure as necessary.
4.5.2 Perform all of the PMCS procedures listed in table 4-1.
4.5.3 Connect FDECU to power source and operate per paragraph 2.4. If operating with the unit hardened for NBC
environments, be sure to operate and maintain both of the NBC blower assemblies according to instructions supplied with
them and be sure they are functioning properly. Check that the unit operates in all modes and that the outside fan is
turning in the correct direction. If the fan is turning backwards, this indicates that the power was connected to the wrong
phase and that two of the power wire leads need to be reversed at the source.
4.5.4 Operate the FDECU using desired control panel to check for proper operation of the controls.
Change the
CONTROL SELECTION switch on the unit control panel as necessary.
Section II. UNIT PREVENTIVE MAINTENANCE CHECKS AND SERVICES
4.6 INTRODUCTION.
4.6.1 General. Preventive Maintenance Checks and Services are essential to the efficient operation of the FDECU and
to prevent possible damage that might occur through neglect or failure to observe warning symptoms in a timely manner.
Checks and services performed by unit maintenance personnel are in table 4-1. This table lists the inspections and care
of the FDECU required to keep it in good operating condition. The procedures are intended to be done if the equipment is
used periodically during the interval period and not if the equipment is in storage. If the equipment has been in storage
and is to be used, perform all of the procedures prior to putting it back into service.
4.6.2 PMCS Procedures. The following paragraphs identify and explain the columns used in the PMCS table.
4.6.2.1 Item No. Column. Numbers in this column are for reference. When completing DA Form 2404 (Equipment
Inspection and Maintenance Worksheet), include the item number for the check/service indicating a fault. Item numbers
also appear in the order that you must do checks and services for the intervals listed.
4.6.2.2 Interval Column. This column tells you when you must do the procedure in the procedure column.
4.6.2.3 Item to be Checked or Serviced Column. This column provides the location and the item to be checked or
serviced. The item location is underlined.
4.6.2.4 Procedure Column. This column gives the procedure you must do to check or service the item listed in the
Check/ Service column to know if the equipment is ready or available for its intended mission or for operation. You must
do the procedure at the time stated in the interval column.
4.6.2.5 "Not Fully Mission Capable If": Column. Information in this column tells you what faults will keep your
equipment from being capable of performing its primary mission. If you made a check and service procedure that shows
faults listed in this column, do not operate the equipment. Follow standard operating procedures for maintaining the
equipment or reporting equipment failure.
4.6.3 Refrigerant Leaks. Oil is carried with the refrigerant as it flows through the refrigeration system. If a leak develops
in the system, the oil will seep out and soak the copper tubing around the leak or drip and soak or puddle on the frame or
other component below the leak. If any oil or seepage is found, a refrigerant leak would be suspected.
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