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STEP 5 -- UNIT START-UP
IMPORTANT
If unit is equipped with a crankcase heater, it should be
energized 24 hours before unit start-up to prevent
compressor damage as a result of slugging.
1 - Rotate fan to check for binding.
2 - Inspect all factory- and field-installed wiring for loose
connections.
3 - After evacuation is complete, open the liquid line and
suction line service valve stems to release the
refrigerant charge (contained in outdoor unit) into the
system.
4 - Replace the stem caps and tighten to the value listed
in table 3.
5 - Check voltage supply at the disconnect switch. The
voltage must be within the range listed on the unit's
nameplate. If not, do not start the equipment until you
have consulted with the power company and the
voltage condition has been corrected.
6 - Connect manifold gauge set for testing and charging
using figure 10 as a guideline.
7 - Set the thermostat for a cooling demand. Turn on
power to the indoor indoor unit and close the outdoor
unit disconnect switch to start the unit.
8 - Recheck voltage while the unit is running. Power must
be within range shown on the unit nameplate.
9 - Check system for sufficient refrigerate using the
procedures outlined in under System Refrigerant.
OPERATING MANIFOLD GAUGE SET AND SERVICE
VALVES
The liquid and suction line service valves are used for
removing refrigerant, flushing, leak testing, evacuating,
checking charge and charging.
Each valve is equipped with a service port which has a
factory-installed valve stem. Figures 15 and 16 provide
information on how to access and operate both angle- and
ball-type service valves.
Torque Requirements
When servicing or repairing heating, ventilating, and air
conditioning components, ensure the fasteners are
appropriately tightened. Table 3 lists torque values for
fasteners.
TORQUE REQUIREMENTS
Parts
Service valve cap
Sheet metal screws
Machine screws #10
Compressor bolts
Gauge port seal cap
To prevent stripping of the various caps used, the
appropriately sized wrench should be used and fitted
snugly over the cap before tightening.
Using Manifold Gauge Set
When checking the system charge, only use a manifold
gauge set that features low loss anti-blow back fittings.
Manifold gauge set used with HFC-410A refrigerant
systems must be capable of handling the higher system
operating pressures. The gauges should be rated for use
with pressures of 0 - 800 psig on the high side and a low
side of 30" vacuum to 250 psig with dampened speed to
500 psi. Gauge hoses must be rated for use at up to 800
psig of pressure with a 4000 psig burst rating.
OPERATING BALL-TYPE SERVICE VALVE:
1 - Remove stem cap with an appropriately sized wrench.
2 - Use an appropriately sized wrenched to open. To open valve,
rotate stem counterclockwise 90°. To close rotate stem
clockwise 90°.
TO OPEN ROTATE STEM
COUNTERCLOCKWISE 90°.
TO CLOSE ROTATE STEM
CLOCKWISE 90°.
SERVICE PORT
SERVICE PORT
SERVICE PORT
Page 13
TABLE 3
Recommended Torque
8 ft.- lb.
11 NM
16 in.- lb.
2 NM
28 in.- lb.
3 NM
90 in.- lb.
10 NM
8 ft.- lb.
11 NM
IMPORTANT
BALL (SHOWN
CLOSED)
CORE
CAP
FIGURE 15
VALVE
STEM
STEM CAP
ML14XC1 SERIES
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