Lennox HP40, Installation Instructions Manual

Page: 7 / 16

Page 7
HP40 COOLING CYCLE (SHOWING MANIFOLD GAUGE CONNECTIONS)
OUTDOOR
COIL
DEFROST THERMOSTAT
EXPANSION/CHECK
VALVE
BIFLOW
FILTER / DRIER
TO
R407C
DRUM
LOW
PRESSURE
HIGH
PRESSURE
COMPRESSOR
REVERSING VALVE
VAPOR
LINE
VALVE
MUFFLER
NOTE − ARROWS INDICATE DIRECTION OF REFRIGERANT FLOW
SERVICE
PORT
SUCTION
EXPANSION/CHECK
VALVE
INDOOR UNIT
OUTDOOR UNIT
LIQUID LINE
SERVICE
PORT
GAUGE MANIFOLD
INTERNAL
COMPRESSOR
LIMIT
DISTRIBUTOR
INDOOR
COIL
FIGURE 6
8 − Close the valve on the inverted R22 drum and the
gauge set valves. Pump the remaining refrigerant
out of the recovery machine and turn the machine off.
9 − Use nitrogen to break the vacuum on the refrigerant
lines and indoor coil before removing the recovery
machine, gauges and R22 refrigerant drum. Rein-
stall pressure tap valve cores into HP32 service
valves.
10 −Install the provided check/expansion valve (ap-
proved for use with R407C refrigerant) in the liquid
line at the indoor coil.
Manifold Gauge Set
Manifold gauge sets used with systems charged with
R407C refrigerant must be able to accommodate higher
system operating pressures. The gauges should be rated
for pressures of 0−800 psi on the high side and a low side
of 30" vacuum to 250 psi with dampened speed of 500 psi.
Gauge hoses must be rated for use at up to 800 psi of
pressure with a 4000 psi burst rating.
Liquid & Vapor Line Service Valves
Access the liquid line and vapor line service valves (fig-
ures 7 and 8) and the gauge ports from inside the unit, be-
hind access panel. The service ports are used for leak
testing, evacuating, charging, and checking the charge.
The valve is equipped with a service port, and a Schrader
valve is factory installed. A service port cap is supplied to
protect the Schrader valve from contamination and to serve
as the primary leak seal.
LIQUID AND VAPOR LINE SERVICE VALVES
VALVE OPEN)
SCHRADER
VALVE
SERVICE
PORT
SERVICE
PORT
CAP
INSERT HEX
WRENCH HERE
TO INDOOR
COIL
TO OUTDOOR
COIL
STEM CAP
SCHRADER VALVE OPEN
TO LINE SET WHEN VALVE IS
CLOSED (FRONT SEATED)
SERVICE
PORT
SERVICE
PORT CAP
STEM CAP
TO OUTDOOR
COIL
INSERT HEX
WRENCH HERE
(VALVE CLOSED)
(VALVE FRONT
SEATED)
TO INDOOR COIL
FIGURE 7