Page 14
6 - Connect manifold gauge set for testing and charging
using figure 9 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 refrigerant using the
procedures outlined 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 14 and 15 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 2 lists torque values for
fasteners.
TABLE 2
TORQUE REQUIREMENTS
Parts
Recommended Torque
Service valve cap
8 ft.- lb.
11 NM
Sheet metal screws
16 in.- lb.
2 NM
Machine screws #10
28 in.- lb.
3 NM
Compressor bolts
90 in.- lb.
10 NM
Gauge port seal cap
8 ft.- lb.
11 NM
IMPORTANT
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.
BALL (SHOWN
CLOSED)
SERVICE PORT
CORE
TO
OPEN
ROTATE STEM
COUNTERCLOCKWISE 90°.
TO
CLOSE
ROTATE STEM
CLOCKWISE 90°.
SERVICE PORT
SERVICE PORT
CAP
STEM CAP
VALVE
STEM
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°.
OPERATING BALL-TYPE SERVICE VALVE:
FIGURE 14
(VALVE STEM SHOWN CLOSED)
INSERT HEX WRENCH HERE
SERVICE PORT CORE
SERVICE PORT CAP
ANGLE-TYPE SERVICE VALVE
(FRONT-SEATED CLOSED)
STEM CAP
(VALVE STEM SHOWN OPEN)
INSERT HEX WRENCH HERE
ANGLE-TYPE SERVICE VALVE
(BACK-SEATED OPENED)
1 - Remove stem cap with an appropriately sized wrench.
2 - Use a service wrench with a hex-head extension (3/16” for liquid
line valve sizes and 5/16” for suction line valve sizes) to back the
stem out counterclockwise as far as it will go.
When service valve is
CLOSED
, the service port is
open to the line set and indoor unit.
When service valve is
OPEN
, the service port is
open to line set, indoor and outdoor unit.
NOTE
- A label with specific torque requirements may be affixed to the
stem cap. If the label is present, use the specified torque.
OPERATING ANGLE-TYPE SERVICE VALVE:
FIGURE 15