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To Access Schrader Port:
1 - Remove service port cap with an adjustable wrench.
2 - Connect gauge to the service port.
3 - When testing is completed, replace service port cap.
Tighten finger tight, then an additional 1/6 turn.
To Open Liquid Line Service Valve:
1 - Remove stem cap with an adjustable wrench.
2 - Using service wrench and 5/16 inch hex head exten
sion back the stem out counterclockwise until the valve
stem just touches the retaining ring.
3 - Replace stem cap. Tighten finger tight, then tighten an
additional 1/6 turn.
WARNING
Do not attempt to backseat this valve. Attempts to
backseat this valve will cause snap ring to explode
from valve body under pressure of refrigerant. Per
sonal injury and unit damage will result.
To Close Liquid Line Service Valve:
1 - Remove stem cap with an adjustable wrench.
2 - Using service wrench and 5/16 inch hex head extension,
turn stem clockwise to seat the valve. Tighten firmly.
3 - Replace stem cap and tighten finger tight, then tighten
an additional 1/6 turn.
Vapor Line Service Valve
VAPOR LINE (BALL TYPE) SERVICE VALVE
(VALVE OPEN)
USE ADJUSTABLE WRENCH
ROTATE STEM CLOCKWISE 90° TO CLOSE
ROTATE STEM COUNTERCLOCKWISE 90° TO OPEN
TO INDOOR COIL
SERVICE PORT
CAP
FIGURE 17
All HP29 units are equipped with a full-service ball valve
on the vapor line, as shown in figure 17. One service port
that contains a Schrader valve core is present in this
valve. A cap is also provided to seal off the service port.
The valve is not rebuildable so it must always be replaced
if failure has occurred.
Opening the Vapor Line Service Valve
1 - Remove the stem cap with an adjustable wrench.
STEM CAP
STEM
BALL
(SHOWN OPEN)
TO OUTDOOR COIL
SERVICE
PORT
SCHRADER VALVE
2 - Using a service wrench, turn the stem counterclock
wise for 1/4 of a turn.
3 - Replace the stem cap and tighten it firmly.
Closing the Vapor Line Service Valve
1 - Remove the stem cap with an adjustable wrench.
2 - Using a service wrench, turn the stem clockwise for 1/4
of a turn.
3 - Replace the stem cap and tighten it firmly.
Leak Testing
After the line set has been connected to the indoor and out
door units, the line set connections and indoor unit must be
checked for leaks.
Never use oxygen to pressurize refrigeration or air
conditioning system. Oxygen will explode on con
tact with oil and could cause personal injury. When
using high pressure gas such as nitrogen or CO2 for
this purpose, be sure to use a regulator that can con
trol the pressure down to 1 or 2 psig (6.9 to 13.8 kPa).
Using an Electronic Leak Detector or Halide
1 - Connect the hoses to the service ports With both man
ifold valves closed, open the valve on the HCFC 22
cylinder (vapor only). Open the liquid line and vapor
line service valves.
2 - Open the high pressure side of the manifold to allow
HCFC 22 into the line set, indoor unit, and the outdoor
unit. Weigh in a trace amount of HCFC 22. [A trace
amount is a maximum of 2 ounces (57g) refrigerant or
3 pounds (31 kPa) pressure]. Close the valve on the
HCFC 22 cylinder and the valve on the high pressure
side of the manifold gauge set. Disconnect HCFC 22
cylinder.
3 - Connect a cylinder of nitrogen with a pressure regulat
ing valve to the center port of the manifold gauge set.
4 - Connect the high pressure hose of the manifold gauge
set to the service port of the vapor line valve. (Normally,
the high pressure hose is connected to the liquid line
port, however, connecting it to the vapor port better
protects the manifold gauge set from high pressure
damage.)
5 - Connect the nitrogen cylinder to the center port on the
manifold gauge set.
6 - Adjust nitrogen pressure to 150 psig (1034 kPa). Open
the valve on the high side of the manifold gauge set
which will pressurize line set and indoor unit.
7 - After a short period of time, open a system port to make
sure the refrigerant added is adequate to be detected.
(Amounts of refrigerant will vary with line lengths.)
Check all joints for leaks, then purge the nitrogen and
HCFC 22 mixture. Correct any leaks and recheck.
Page 16
WARNING
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