24
I
Pump Down
Pump down means collecting all refrigerant gas in the
system back into the outdoor unit without losing any of
the gas. Pump down is used when the unit is to be
moved or before servicing the refrigerant circuit.
Pump Down Procedure
Be sure to carry out pump down with the unit in
cooling mode.
(1) Connect the Lo side charging hose of the manifold
valve to the service port on the wide tube service
valve.
(2) Using a hex wrench, turn the narrow tube service
valve clockwise all the way to close the service
valve. (Be sure to confirm that the wide tube service
valve is fully open.)
(3) Press the operation button and start cooling oper-
ation.
(4) When the low pressure gauge reading falls to 14.2 to
7.1 psi (1 to 0.5 kg/cm
2
), fully close the wide tube
valve stem. Then quickly stop the unit.
(5) Disconnect all gauges and hoses, and replace the
valve caps as they were before.
I
Basic Functions of the Service Valves
The basic functions of the service valves are given in Table 8 below.
Action
Narrow Tu
b
e
S
ervice
Valve (2-Way)
Wide Tu
b
e
S
ervice
Valve (
3
-Way)
CLO
S
ED
F
u
lly OPEN
F
u
lly OPEN
S
hippi
ng
Operati
ng
a
n
d
te
s
t r
unn
i
ng
the air co
n
ditio
n
er
Mea
su
ri
ng
pre
ssu
re
a
n
d
g
a
s
char
g
i
ng
Air p
u
r
g
i
ng
with
a vac
uu
m p
u
mp
CLO
S
ED
Valve cap
S
tem
O-ri
ng
*
*
Table 8
*
The service port on the wide tube ser-
vice valve uses a Schrader core valve
to access the refrigerant system.
Therefore, be sure to use a hose con-
nector which has a push-pin inside.
(Fig. 60a)
PU
S
H
Ho
s
e with p
us
h-pi
n
S
ervice valve
Fig. 60a
Clo
s
e
Hex
wre
n
ch
Ope
n
Fig. 60b
CAUTION
When opening or clos-
ing the service valve
stem, use the accessory
hex wrench. Be sure to
fully seat the wrench
before turning the valve.
External diameter of service port
R410A: 5/16"
NOTE
07-105 KS0971-1271 5/10/07 9:17 AM Page 24
