1. After unit is furred in, but prior to unit start-up, make sure
no foreign material remains in the unit paying particular
attention to the drain pan and drain line. Blockage of the
drain line will result in water overflow of the drain pan.
2. Open supply and return water service valves.
3. If unit does not have the automatic flow control option,
balance water flow rate with hand valve on return line.
4. Replace front access cover (see Figure 3).
5. Put filter into position.
6. Install return air grille.
7. All windows and doors should be in and closed before
starting up the unit.
8. Switch unit to "on" and check for proper operation of
fans, fan speed switch, and thermostat.
9. When there is a high amount of moisture in the air, the
initial pulidown should be very gradual (high fan speed
for maximum air flow with reduced GPM and elevated
chilled water temperature for reduced capacity). Outside
air supply and toilet exhaust systems should not be
operated until the gradual pulldown has been completed.
If these steps are taken, the possibility of the unit
sweating will be reduced.
1. Filters must be clean to obtain maximum unit
performance. They should be inspected every three or
four months under normal operating conditions and be
replaced when necessary. Units should never be run
without a filter.
2. In areas where airborne bacteria produce growth in the
drain pan, it may be necessary to treat chemically to
minimize the problem. Contact your local sales
representative or one of the many companies dealing
with water conditioning.
3. The condensate drain pan can pick up lint and dirt,
especially with dirty filters. Inspect twice a year to avoid
the possibility of overflow.
4. The fan motor has been oiled at the factory. It is not
necessary to oil the first six months under continuous
operation. Oil every six months with one teaspoon or five
cc per bearing of SAE No. 20 nondetergent oil. Do not
overlubricate.
5. The coil must be clean to obtain maximum performance.
Check once a year under normal operating conditions,
and if dirty, brush or vacuum clean. Care must be taken
not to damage the aluminum fins while cleaning.
Caution: Fin edges are sharp.
Maintenance
1. If fan or motor service is required on the S03 or the S04,
the fan motor can be removed through the return air
opening as follows:
a. Shut off electrical power to unit.
b. Remove return air grille panel.
c. Remove front access cover.
d. Disconnect the fan motor leads at the wiring box.
e. Remove the bottom half of the fan housing by taking
out the two screws on the housing.
f. Remove the clips that hold the motor to the motor
base.
g. Remove the motor.
h. Fan wheel is pressed on motor shaft, pull to remove.
i. Reverse process to reassemble.
2. If fan motor service is required on the S06 or S08, the fan
motor can be removed through the return air opening as
follows:
a. Shut off electrical power to unit.
b. Remove return air grille panel.
c. Remove front access cover (see Figure 3).
d. Disconnect the fan motor leads at the wiring box.
e. Remove the screws that hold the inlet ring to the fan
housing.
f. Remove the fan wheel, motor, and inlet ring assembly
from the fan housing.
g. Loosen fan wheel setscrew.
h. Remove the three screws holding the motor to the
inlet ring.
i. Service can now be performed.
j. Reverse process to reassemble.
3. The electric heater elements, if furnished, are designed
with high limit control set to trip out if the cabinet
temperature becomes excessive and automatically reset
when the cabinet temperature returns to normal.
If the high limit is opening the circuit, the unit is not
performing properly and should be checked to find the
cause. Some probable causes would be not enough air
over the heater due to dirty filter, fan motor not operating,
dirty coil, fan wheel loose on the motor shaft, or loose
electrical connections.
4. If the electric heater should require service, it can be
done in the following manner:
a. Shut off electrical power to the unit. Caution: There
may be more than one power source on the unit.
b. Remove the return air grille and front access cover.
c. Remove the electric heater junction box cover.
d. The high-limit control can be replaced without
removing the element from the unit. It is done by
removing the nut on the appropriate terminal post and
lifting the defective part out.
e. The entire element can be removed by disconnecting
the wires from the terminal posts and removing the
screws in the back of the junction box that hold the
heater to the support bracket. Slide the heater out and
replace.
f. The electric heater contactor is located in the field
wiring box (see Figures 3 and 5).
Service
Start-up
When writing for service or replacement parts, direct your
letters to McQuayService, and refer to the model number
and the serial number of the heater as stamped on the serial
plate attached to the heater kit. If replacement parts are
required, give the date of the heater kit installation and the
date of the failure; also, give description of replacement
parts and explanation of malfunction.
Replacement Parts
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