# 48387H005
Page 9
gauges, and R22 refrigerant drum. Re-install pressure tap
valve cores into the 4SCU13LE unit’s service valves.
11.
Install the factory-supplied fixed orifice (or thermal
expansion valve approved for use with R410A
refrigerant)
in the liquid line at the indoor coil.
Refrigerant Metering Device
4SCU13LE units are designed for use with either fixed
orifice or TXV systems. Refer to the appropriate following
section for information on installing the chosen refrigerant
metering device.
Fixed Orifice Systems
4SCU13LE units are shipped with a fixed orifice refriger-
ant metering device. Replace the existing indoor unit fixed
orifice with the orifice supplied with this unit. Place the
supplied fixed orifice sticker on the indoor cabinet after
installation. See Table 3 for the proper fixed orifice size for
each unit. In nonstandard applications, the provided fixed
orifice may not be appropriately sized.
Install the fixed orifice as shown in Figure 11. Do not twist cap
tubes when loosening the seal nut from the orifice housing.
Use wrench to back up the distributor.
Expansion Valve Systems
Expansion valves equipped with Chatleff-type fittings are
available from the manufacturer. See Table 4 for proper
TXV for each unit.
To install an expansion valve (see Figure 11):
1. Separate the distributor assembly and remove the
piston orifice and used teflon seal. Insert nozzle end of
the expansion valve along with a new teflon seal into the
distributor and tighten to 20 – 30 ft. lbs. Use backup
wrench on all wrench flats.
Overtightening will crush
the teflon seal and may cause a leak.
2. Attach liquid line portion of distributor assembly along
with new teflon seal to the inlet of the expansion
valve. Tighten to 20 – 30 ft. lbs. Use backup wrench
on all wrench flats.
Overtightening will crush the
teflon seal and may cause a leak.
3. Connect the external equalizer line to the equalizer
port on the suction line and tighten to 8 ft. lbs.
4. Strap the superheat sensing bulb to the suction header.
If installing an expansion valve on an indoor coil that
previously used a fixed orifice, be sure to remove the
existing fixed orifice. Failure to remove a fixed orifice
when installing an expansion valve to the indoor coil will
result in improper operation and damage to the system.
Metering Device Installation
Figure 11
Fixed Orifice Data
Table 3
l
e
d
o
M
t
r
a
P
r
e
b
m
u
N
l
l
i
r
D
e
z
i
S
8
1
-
E
L
3
1
U
C
S
4
7
0
-
4
8
4
0
0
1
3
5
0
.
4
2
-
E
L
3
1
U
C
S
4
8
0
-
4
8
4
0
0
1
7
5
0
.
0
3
-
E
L
3
1
U
C
S
4
3
1
-
4
8
4
0
0
1
3
6
0
.
6
3
-
E
L
3
1
U
C
S
4
3
2
-
4
8
4
0
0
1
4
7
0
.
2
4
-
E
L
3
1
U
C
S
4
4
2
-
4
8
4
0
0
1
6
7
0
.
8
4
-
E
L
3
1
U
C
S
4
0
3
-
4
8
4
0
0
1
2
8
0
.
0
6
-
E
L
3
1
U
C
S
4
9
3
-
4
8
4
0
0
1
2
9
0
.
Table 4
TXV Data
l
e
d
o
M
t
r
a
P
r
e
b
m
u
N
,
4
2
-
,
8
1
-
E
L
3
1
U
C
S
4
6
3
-
,
0
3
-
1
0
V
X
T
4
A
8
4
-
,
2
4
-
E
L
3
1
U
C
S
4
2
0
V
X
T
4
A
0
6
-
E
L
3
1
U
C
S
4
3
0
V
X
T
4
H
