Step 7 - Install Accessories - Bryant Legacy Series Installation, Start-Up And Service Instructions Manual

Evaporator Capacity Control Liquid Line Solenoid Valve
Many older unit designs included automatic capacity controls
that sensed changes in suction pressure and could increase or
decrease compressor capacity automatically as the evaporator
load changed. Control systems were used on these units that
had the thermostat's second stage contacts control a capacity
control liquid line solenoid valve to open or shutoff a portion
of the evaporator surface without any direct connection to the
compressor circuit.
This form of system capacity staging control is not possible
with 569J models. If this installation is a retrofit for a unit that
included automatic pressure-operated unloading, check the ex-
isting thermostat and liquid solenoid valve. When found, con-
vert the evaporator second stage solenoid control into a drop-
solenoid control. Use the two SVR relays and transformer as
required on 569J***D/E/F models (above); wire the SVRs and
transformer per two solenoid valve systems.
SELECTING AN ACCUMULATOR
Because all 569J models use scroll compressors, an accumula-
tor is not required. If an accumulator is to be added, check the
accumulator manufacturer's literature carefully for indication
of its suitability for use with R-410A; look for minimum work-
ing pressure of 200 psig (1380 kPa). Select the accumulator
first on the basis of its cataloged minimum capacity (tons) to
ensure oil return from the accumulator, then on tube size or
holding capacity.
MAKE PIPING CONNECTIONS
Piping connections at the 569J unit are ball valves with stub
tube extensions. Do not open the unit service valves until all
interconnecting tube brazing has been completed. The stub
tube connections include
Schrader valve cores (see Fig. 11). Before making any brazed
connections to the unit service valves, remove both Schrader
valve caps and cores and save for re-installation. Connect a
source for nitrogen to one of these service fittings during tube
brazing to prevent the formation of copper oxides inside the
tubes at brazed joints.
When connecting the field tubing to the 569J service valves,
wrap the valves in wet rags to prevent overheating.
Pressure-test all joints from outdoor unit connections over to
the evaporator coil, using nitrogen as pressure and with soap-
and-bubbles.
When pressure-testing is completed, remove the nitrogen source
at the outdoor unit service valves and re-install the two Schrader
valve cores. Torque the cores to 2-3 in-lbs (23-34 N-cm).
FACTORY
HIGH-FLOW
ACCESS PORT
SERVICE VALVE
WITH STEM CAP
Fig. 11 — Typical Piping Connection Assembly
EVACUATION/DEHYDRATION
Evacuate and dehydrate the connected refrigeration system(s)
(excluding the 569J unit) to 500 microns using a two-stage
vacuum pump attached to the service ports outside the 569J
service valves, following description in GTAC II, Module 4,
System Dehydration.
1 / -in. SAE service fittings with
4
FIELD SERVICE
ACCESS PORT
(SCHRADER CORE)
SWEAT
CONNECTION
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal injury,
death and/or equipment damage.
R-410A refrigerant systems operate at higher pressures than
standard R-22 systems. Do not use R-22 service equipment or
components on R-410A refrigerant equipment.
This unit is designed for use with Puron (R-410A) refrigerant.
Do not use any other refrigerant in this system.
Puron (R-410A) refrigerant is provided in pink (rose) colored
cylinders. These cylinders are available with and without dip
tubes; cylinders with dip tubes will have a label indicating this
feature. For a cylinder with a dip tube, place the cylinder in the
upright position (access valve at the top) when removing liquid
refrigerant for charging. For a cylinder without a dip tube, in-
vert the cylinder (access valve on the bottom) when removing
liquid refrigerant.
Because Puron (R-410A) refrigerant is a blend, it is strongly rec-
ommended that refrigerant always be removed from the cylinder
as a liquid. Admit liquid refrigerant into the system in the dis-
charge line. If adding refrigerant into the suction line, use a com-
mercial metering/expansion device at the gauge manifold; re-
move liquid from the cylinder, pass it through the metering de-
vice at the gauge set and then pass it into the suction line as a
vapor. Do not remove Puron (R-410A) refrigerant from the cyl-
inder as a vapor.
PRELIMINARY CHARGE
Before starting the unit, charge R-410A liquid refrigerant into
the high side of each 569J circuit through the liquid service
valve(s). The amount of refrigerant added must be at least 80%
of the operating charge listed in Tables 5 or 6 for LINEAR line
length LESS the factory charge quantity (if factory shipping
charge has not been removed). See example below.
Allow high and low side pressures to equalize. If pressures do
not equalize readily, charge R-410A vapor (using special ser-
vice manifold with expansion device) into the suction line ser-
vice port for the low side of system to assure charge in the
evaporator. Refer to GTAC II, Module 5, Charging, Recover,
Recycling, and Reclamation for liquid charging procedures.
Example:
569J*12A/B
60-ft (18.3 m) linear line length
Equivalent line length 90-ft (27.4 m)
Liquid Lift: 20-ft (6.1 m)
Select line sizes from Table 8 (569J***A/B/G/H):
Liquid 1 / in.
2
Suction 1 / in.
1
8
Charge 23.1 lbs (at 75-ft linear length)
80% of Operating Charge:
0.80 x 23.1 = 18.5 lbs
Factory Shipping Charge: 9 lbs
Field-Charge quantity: 18.5 - 9.0 = 9.5 lbs
Step 7 — Install Accessories
Accessories requiring modifications to unit wiring should be
completed now. These accessories may include Winter Start
controls and Low Ambient controls. Refer to the instructions
shipped with the accessory.
13
WARNING