Final Tubing Check - Bryant Preferred Series Installation Instructions Manual

123A, 126B, 126C: Installation Instructions

Final Tubing Check

IMPORTANT: Check to be certain factory tubing on both indoor and
outdoor unit has not shifted during shipment. Ensure tubes are not
rubbing against each other or any sheet metal or wires. Pay close
attention to feeder tubes, making sure wire ties on feeder tubes are
secure and tight.
Installing with Indoor Piston
Outdoor Unit Connected to Factory Approved Indoor Unit
Check piston size shipped with indoor unit to see if it matches required
indoor piston size. If it does not match, replace indoor piston with
correct piston size.
NOTE: Correct pistons are shipped with select outdoor units in the
accessory bag and are only for use in certain qualified and approved fan
coils, i.e. FB4C. (See Product Data for list of approved fan coils that use
accessory piston.)
The piston included with the FFMANP* and FPMAN* fan coils are
unique to those products and CANNOT be replaced with the piston
shipped with outdoor unit. Refer to the AHRI Directory to check if a
certain combination can use a piston or requires an accessory TXV.
When changing indoor piston, use a back−up wrench. Hand tighten hex
nut, then tighten with wrench 1/2 turn. Do not exceed 30 ft−lbs. The
indoor piston contains a Teflon ring (or seal) which is used to seat
against the inside of distributor body, and must be installed properly to
ensure proper seating. See Fig.
Fig. 5 – Indoor (Cooling) Piston
Units with Cooling Mode TXV
Units installed with cooling mode TXV require charging by the
subcooling method.
1. Operate unit a minimum of 15 minutes before checking charge.
2. Measure liquid service valve pressure by attaching an accurate gage
to service port.
3. Measure liquid line temperature by attaching an accurate thermistor
type or electronic thermometer to liquid line near outdoor coil.
4. Refer to unit rating plate for required subcooling temperature.
5. Refer to Table 2 - Rating Plate (required) Subcooling Temperature.
Find the point where required subcooling temperature intersects
measured liquid service valve pressure.
6. To obtain required subcooling temperature at a specific liquid line
pressure, add refrigerant if liquid line temperature is higher than
indicated or reclaim refrigerant if temperature is lower. Allow a
tolerance of ?3°F (±1.7°C).
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
5.
Units with Indoor Piston
Units installed with indoor pistons require charging by the superheat
method.
The following procedure is valid when indoor airflow is within ±21
percent of its rated CFM.
1. Operate unit a minimum of 15 minutes before checking charge.
2. Measure suction pressure by attaching an accurate gage to suction
valve service port.
3. Measure suction temperature by attaching an accurate thermistor
type or electronic thermometer to suction line at service valve.
4. Measure outdoor air dry-bulb temperature with thermometer.
5. Measure indoor air (entering indoor coil) wet-bulb temperature
with a sling psychrometer.
6. Refer to Table 3
temperature and evaporator entering air wet-bulb temperature. At
this intersection, note superheat. Where a dash (--) appears on the
table, do not attempt to charge system under these conditions or
refrigerant slugging may occur. Charge must be weighted in, adding
or removing 0.6 oz/ft of 3/8 liquid line above or below 15 feet
(4.6m) respectively (refer to
refrigerant charge).
7. Refer to Table 4
superheat temperature (from #6 above) and suction pressure. At this
intersection, note suction line temperature.
8. If unit has a higher suction line temperature than charted
temperature, add refrigerant until charted temperature is reached.
9. If unit has a lower suction line temperature than charted
temperature, reclaim refrigerant until charted temperature is
reached.
10. When adding refrigerant, charge in liquid form into suction service
port using a flow-restricting device.
11. If outdoor air temperature or pressure at suction valve changes,
charge to new suction line temperature indicated on chart.
12. Optimum performance will be achieved when the operating charge
produces 10°F suction superheat at suction service valve with 95°F
A10342
(35°C) outdoor ambient and 80°F (27°C) dry bulb (67°F / 19°C)
wet bulb) indoor temperature (DOE "A" test conditions) at rated
airflow.
4
- Superheat Charging - AC Only. Find outdoor
Table 5 for factory and required
- Required Suction-Line Temperature. Find