5390862-UIM-A-0318
Johnson Controls Unitary Products
7
7. Pass the temperature sensing bulb tube for the TXV through the
tube opening in the split grommet of the access panel.
8. Install the TXV bulb to the vapor line near the cabinet, using the
bulb clamp(s) furnished with the TXV assembly. Ensure the bulb is
making maximum contact. See Figures 7, 8 & 9, and accomplish
the following:
a.
If possible, install the temperature bulb on a horizontal run of
the vapor line. Ensure that the bulb is installed at a 10 o’clock
or 2 o’clock position. See Figure 10.
b.
If bulb installation is made on a vertical run, ensure that the
bulb is a minimum of 16 inches (20.3 cm) away from elbow
coming out of the coil. Position the bulb with the tail of the
bulb at the top, so that the bulb acts as a reservoir. See Fig-
ure 9.
c.
Insulate the bulb using thermal insulation provided to protect
it from the effect of the surrounding ambient temperature.
Cover completely to insulate.
9. After line set is installed, leak test the system.
SECTION V: EVACUATION
Evacuate the system to 500 microns or less. If a leak is suspected, leak
test with dry nitrogen to locate the leak. Repair the leak and test again.
To verify that the system has no leaks, simply close the valve to the
vacuum pump suction to isolate the pump and hold the system under
vacuum. Watch the micron gauge for a few minutes. If the micron
gauge indicates a steady and continuous rise, it’s an indication of a
leak. If the gauge shows a rise, then levels off after a few minutes and
remains fairly constant, it’s an indication that the system is leak free but
still contains moisture and may require further evacuation if the reading
is above 500 microns.
SECTION VI: SYSTEM CHARGE
To ensure that your unit performs at the published levels, it is important
that the indoor airflow is determined and refrigerant charge added
accordingly.
MEASURE INDOOR AIR FLOW
To determine rated air flow for a specific match, consult the technical lit-
erature at
www.upgnet.com
. When attempting to match this air flow,
select the lowest possible speed tap, measure the actual flow, and
adjust as necessary.
To measure actual air flow, it is not an acceptable method to just
check the jumper pin setting tables and to assume 0.5” water col-
umn total external static pressure.
To determine indoor air flow, first measure the static pressure with a
manometer between the filter and inlet air opening on the unit. On a sin-
gle-piece or modular air handler, take a second reading in the supply
duct leaving the air handler unit. On a furnace take the second reading
after the heat exchanger but before the indoor coil. Add the negative
return static to the positive supply static to determine the system total
static pressure. Treat the negative return static as a positive pressure
(even though it is a negative reading). If there is static pressure on the
blower (i.e. -.10) return, add it to a supply static (.40) which equals a
(.50) total system static pressure. Compare this value to the table for
the indoor unit's static pressure vs. CFM or to a curve chart.
CAUTION
In all cases, mount the TXV temperature sensing bulb after vapor line
is brazed and sufficiently cooled.
Failure to use suction line split grommet may result in TXV failure.
FIGURE 7:
TXV Bulb and Equalizer line Installations
FIGURE 8:
Proper Bulb Location
!
T
X
V
B
U
LB
(W
rap
w
ith
insu
l
ation
.)
VAPOR
LIN
E
LI
QU
I
D
LIN
E
TV
X
EQUA
LIZ
ER
LIN
E
THERMA
L
E
X
PA
N
S
I
O
N
VA
L
VE
(
T
X
V
)
D
I
STR
IB
UTOR
B
OD
Y
A
0279-002
T
X
V
B
U
LB
(
Co
v
er
co
m
p
l
ete
ly
w
ith
insu
l
ation
.)
VAPOR
LIN
E
O
F LIN
E
SET
A
0269-002
C
L
AMP
A
DETAIL A
T
X
V
SE
N
S
ING B
U
LB
(
Pass
through
sp
l
it
ho
l
e
in
gro
mm
et
.)
VAPOR
LIN
E
N
UT
N
UT
B
u
lb
at
10
o
’
c
l
oc
k
position
.
B
u
lb
at
2
o
’
c
l
oc
k
position
.
SCRE
W
SCRE
W
C
L
AMP
FIGURE 9:
Vertical Temperature Bulb Orientation
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