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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 and 8.
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 8.
b. If bulb installation is made on a vertical run, ensure that the bulb
is a minimum of 8 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.
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.
TXV SENSING BULB
Bulb at
(Pass through split hole
10 o'clock
in grommet.)
position.
SCREW
NUT
CLAMP
CLAMP
VAPOR
LINE
Bulb at
2 o'clock
position.
NUT
SCREW
DETAIL A
FIGURE 8: Proper Bulb Location
SECTION V: EVACUATION
It will be necessary to 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
CAUTION
!
If a field installed device is placed in the inner-connecting refrigerant
lines that can store a significant refrigerant charge (ex: refrigerant
mass flow meter, liquid receiver, etc.) the unit may not perform as
designed. If such a performance affecting device is installed and it is
possible to check the unit in heating mode, the unit pressures should
be confirmed in heating mode. Refer to the heating charging charts
located in this installation manual.
CAUTION
!
Refrigerant charging should only be carried out by a licensed quali-
fied air conditioning contractor.
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.
Johnson Controls Ducted Systems
TXV BULB
(Cover completely
with insulation.)
A
VAPOR LINE
OF LINE SET
A0269-002
To measure actual air flow, it is not an acceptable method to just
check the jumper pin setting tables and is to assume 0.5" water
column 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.
CHARGING THE UNIT
CAUTION
!
Always charge in liquid form. Take care not to slug the compressor.
The factory charge in the outdoor unit includes enough charge for the
unit, 15 ft. (4.6 m) of refrigerant piping, and the smallest indoor coil/air
handler match-up. Some indoor coil/air handler matches may require
additional charge.
CAUTION
!
Compressor damage will occur if system is improperly charged. On
new system installations, charge system per tabular data sheet for
the matched coil and follow guidelines in this instruction.
See Tabular Data Sheet provided in unit Customer Booklet for charge
requirements. The "TOTAL SYSTEM CHARGE" must be permanently
marked on the unit data plate.
CAUTION
!
Do not leave the system open to the atmosphere. Unit damage could
occur due to moisture being absorbed by the POE oil in the system.
This type of oil is highly susceptible to moisture absorption.
TOTAL SYSTEM CHARGE DETERMINED
1. Determine outdoor unit factory charge from Tabular Data Sheet.
2. Determine indoor coil adjustment (if any) from Tabular Data Sheet.
3. Calculate the additional charge for refrigerant piping using the Tab-
ular Data Sheet if line length is greater than 15 feet (4.6 m).
4. Total system charge = item 1 + item 2 + item 3.
5. Check the unit against the pressure value listed on the cooling chart
on the unit or the appropriate heat charging chart on the following
pages of this Installation Manual. Make any adjustment necessary.
6. Add or subtract refrigerant to obtain the pressure listed on charging
chart. Make sure to adjust the total system charge by the amount
added or removed to obtain charging chart pressures. Permanently
mark the unit data plate with the total amount of refrigerant in the
system.
WARNING
!
DO NOT attempt to pump "Total System Charge" into outdoor unit for
maintenance, service, etc. This may cause damage to the compres-
sor and/or other components. Recover and weigh "System Charge"
into an appropriate recovery cylinder for any instances requiring
evacuation.
CAUTION
!
IT IS UNLAWFUL TO KNOWINGLY VENT, RELEASE OR DIS-
CHARGE REFRIGERANT INTO THE OPEN AIR DURING REPAIR,
SERVICE, MAINTENANCE OR THE FINAL DISPOSAL OF THIS
UNIT.
5604542-UIM-B-0419
7
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