Installation manual
Page 84 IM-487
Maintenance
Planned Maintenance
Planned maintenance is the best way to avoid unnecessary
expense and inconvenience. Have this system inspected at reg-
ular intervals by a qualified service technician. The required
frequency of inspections depends upon the total operating time
and the indoor and outdoor environmental conditions. Routine
maintenance should cover the following items:
1. Tighten all belts, wire connections, and setscrews.
2. Clean the evaporator and condenser coils mechanically or
with cold water, if necessary. Usually any fouling is only
matted on the entering air face of the coil and can be
removed by brushing.
3. Lubricate the motor and fan shaft bearings.
4. Align or replace the belts as needed.
5. Clean or replace the filters as needed.
6. On units with remote condensing units:
a. Check each circuit's refrigerant sightglass when the
circuit is operating under steady-state, full load condi-
tions. The sightglass should then be full and clear. If it
is not, check for refrigerant leaks.
Note: A partially full sight glass is not uncommon at
part load conditions.
b. Check for proper superheat.
c. Refer to the condensing unit IOM for additional
planned maintenance.
7. Check for blockage of the condensate drain. Clean the
condensate pan as needed.
8. Check the power and control voltages.
9. Check the running amperage of all motors.
10.Check all operating temperatures and pressures.
11.Check and adjust all temperature and pressure controls
as needed.
12.Check and adjust all damper linkages as needed.
13.Check the operation of all safety controls.
14.Examine the gas furnace (see Bulletin No. IM 684 or685).
15.Lubricate the door latch mechanisms.
Unit Storage
Location
The McQuay Rooftop Packaged System Unit is an outdoor
unit. However, the schedule may dictate storage either on the
ground or in its final position at the site. If the unit is stored on
the ground, take these additional precautions:
1. Support the unit well along the length of the base rail.
2. Level the unit (no twists or uneven ground surface).
3. Provide proper drainage around the unit to prevent flood-
ing of the equipment
4. Provide adequate protection from vandalism, mechanical
contact, etc. The condenser fins are particularly vulnerable
to damage by even light contact with ground based objects.
5. Provide unit doors are securely closed and locked.
6. If isolation dampers are provided, verify that they are prop-
erly installed and fully closed to prevent the entry of ani-
mals and debris through the supply and return air openings.
7. Fit units without isolation dampers with covers over the
supply and return air openings.
Preparation
Supply (and Return) fans
1. Move the motor base to check and lubricate slides and
leadscrews.
2. Remove the drive belts, tag them with the fan name and
unit serial number and store them in a conditioned space
out of direct sunlight.
3. Once every two weeks, rotate the fan and motor shafts.
Mark the shaft positions fIrst to make sure they stop in a
different position.
4. Depending on local climatic conditions, condensate ~ col-
lect on components inside the units. To prevent surface
rust and discoloration, spray all bare metal parts with a
rust preventive compound. Pay close attention to fan
shafts, sheaves, bearings and bearing supports,
Cabinet Sections
1. Once a month, open a door on each section and verify that
no moisture or debris is accumulating in the unit.
Gas Furnace
If the unit is equipped with a gas furnace, close the gas shut-
off valve and open furnace control switch S3.
Control Compartment
1. McQuay International recommends that the electronic con-
trol equipment in the unit be stored in a 5% to 95% RH
(non-condensing) environment.
Installation and maintenance must be performed
only by trained personnel who are experienced with
this type of equipment and familiar with local codes
and regulations.
DANGER
Moving machinery and electrical power hazards.
May cause severe personal injury or death.
Lock out and tag out all power before
servicing equipment.
WARNING
Sharp edges are inherent to sheet metal parts,
screws, clips, and similar items. May cause
personal injury.
Exercise caution when servicing equipment.