Step 5 -- Unit Start-Up; Operating Manifold Gauge Set And Service Valves - Lennox XP14-018-230 Installation Instructions Manual

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
vapor line service valve stems to release the refriger­
ant charge (contained in outdoor unit) into the sys­
tem.
4 - Replace the stem caps and tighten to the value listed
in table 2.
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 volt­
age condition has been corrected.
6 - Connect manifold gauge set for testing and charging.
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 refrigerant using the pro­
cedures outlined under Checking Refrigerant
Charge.
OPERATING MANIFOLD GAUGE SET AND
SERVICE VALVES
The liquid and vapor line service valves are used for re­
moving 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 ap­
propriately tightened. Table 2 lists torque values for fas­
teners.
TABLE 2
TORQUE REQUIREMENTS
Parts Recommended Torque
Service valve cap 8 ft.- lb.
Sheet metal screws 16 in.- lb.
Machine screws #10 28 in.- lb.
Compressor bolts 90 in.- lb.
Gauge port seal cap 8 ft.- lb.
To prevent stripping of the various caps used, the
appropriately sized wrench should be used and fitted
snugly over the cap before tightening.
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 sys­
tems must be capable of handling the higher system op­
erating 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.
1 - Remove stem cap with an appropriately sized wrench.
2 - Use an appropriately sized wrench to open. To open valve, rotate
11 NM
2 NM
3 NM
10 NM
11 NM
Page 13
IMPORTANT
Using Manifold Gauge Set
OPERATING BALL-TYPE SERVICE VALVE
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
CORE
SERVICE PORT
CAP
FIGURE 15
BALL (SHOWN
CLOSED)
VALVE
STEM
STEM CAP
XP14 SERIES