Lennox HP40, Installation Instructions Manual

Page: 8 / 16

Page 8
IMPORTANT
Service valves are closed to the heat pump unit and
open to line set connections. Do not open until re-
frigerant lines have been leak tested and evacuat-
ed. All precautions should be exercised in keeping
the system free from dirt, moisture and air.
Accessing the Schrader Port:
1 − Remove service port cap with an adjustable wrench.
2 − Connect gauge to the service port.
3 − When testing is completed, replace the service port
cap. Tighten finger tight, then tighten an additional 1/6
turn.
To Open Liquid or Vapor Line Service Valve:
1 − Remove the stem cap with an adjustable wrench.
2 − Use a service wrench with a hex−head extension to
back the stem out counterclockwise as far as pos-
sible.
WARNING
Do not attempt to backseat this valve. Attempts to
backseat this valve will cause the snap ring to ex-
plode from the valve body under pressure of the re-
frigerant. Personal injury and unit damage will result.
3 − Replace the stem cap. Tighten finger tight, then tighten
an additional 1/6 turn.
To Close Liquid or Vapor Line Service Valve:
1 − Remove the stem cap with an adjustable wrench.
2 − Use a service wrench with a hex−head extension to
turn the stem clockwise to seat the valve. Tighten
firmly.
3 − Replace the stem cap. Tighten finger tight, then tight-
en an additional 1/6 turn.
VAPOR LINE (BALL−TYPE) SERVICE VALVE
(VALVE OPEN)
SCHRADER
VALVE
SERVICE PORT
SERVICE
PORT
CAP
STEM CAP
TO OUTDOOR
COIL
STEM
USE ADJUSTABLE WRENCH.
ROTATE STEM CLOCKWISE 90 TO CLOSE.
ROTATE STEM COUNTERCLOCKWISE 90 TO OPEN.
BALL
(SHOWN OPEN)
TO INDOOR COIL
FIGURE 8
Vapor Line (Ball−Type) Service Valve −− 5−Ton Units
A ball-type full−service valve is used on five-ton units. These
vapor line service valves function the same way, the differ-
ences are in construction. Valves are not rebuildable. If a
valve has failed, it must be replaced. A ball valve is il-
lustrated in figure 8.
The ball valve is equipped with a service port and a fac-
tory−installed Schrader valve. A service port cap is
supplied to protect the Schrader valve from contami-
nation and to assure a leak−free seal.
Leak Testing
After the line set has been connected to the indoor and
outdoor units, check all connections for leaks.
IMPORTANT
The leak detector must be capable of sensing HFC
refrigerant.
WARNING
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 for this
purpose, be sure to use a regulator that can control
the pressure down to a range of 6.9 to 13.8 kPa.
Using an Electronic Leak Detector
1 − Connect a cylinder of nitrogen with a pressure regulat-
ing valve to center port of manifold gauge set.
2 − Connect the high pressure hose of the manifold
gauge set to the service port of the vapor valve. (Nor-
mally, the high pressure hose is connected to the liq-
uid line port, however, connecting it to the vapor port
better protects the manifold gauge set from high pres-
sure damage.)
3 − With both manifold valves closed, open the valve on
the R407C cylinder (liquid only).
4 − Open the high pressure side of the manifold to allow
R407C into the line set and indoor unit. Weigh in a
trace amount of R407C. (A trace amount is a maxi-
mum of 59 ml or 21 kPa pressure.)
Close the valve on
the R407C cylinder and the valve on the high pres-
sure side of the manifold gauge set. Disconnect
R407C cylinder and attach a nitrogen cylinder.
5 − Adjust nitrogen pressure to 1034 kPa. Open the valve
on the high side of the manifold gauge set which will
pressurize line set and indoor unit.
6 − After a short period of time, open a refrigerant port to
make sure the refrigerant added is adequate to be de-
tected. (Amounts of refrigerant will vary with line
lengths.) Check all joints for leaks. Purge nitrogen
and R407C mixture. Correct any leaks and recheck.