Step 11 -Start- -Up; Step 12 -Check Charge - Bryant Preferred 163A Installation Instructions Manual

STEP 11 —Start- -Up
CAUTION
!
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this caution may result in minor personal
injury, equipment damage or improper operation.
To prevent compressor damage or personal injury, observe the
following:
S Do not overcharge system with refrigerant.
S Do not operate unit in a vacuum or at negative pressure.
S Do not disable low pressure switch in scroll compressor
applications.
S Dome temperatures may be hot.
CAUTION
!
PERSONAL INJURY HAZARD
Failure to follow this caution may result in personal
injury.
Wear safety glasses, protective clothing, and gloves when
handling refrigerant and observe the following:
S Front seating service valves are equipped with Schrader
valves.
CAUTION
!
ENVIRONMENTAL HAZARD
Failure to follow this caution may result in environmental
damage.
Federal regulations require that you do not vent refrigerant
to the atmosphere. Recover during system repair or final
unit disposal.
FOLLOW THESE STEPS TO PROPERLY START UP
THE SYSTEM:
1. After system is evacuated, fully open liquid and vapor
service valves.
2. Unit is shipped with valve stem(s) front seated (closed)
and caps installed. Open fully by turning the stem counter
clockwise as far as it will go, and tighten lightly. This
opens the valve to refrigerant flow, and closes the gage
port. To leave gage port open, fully open the valve, and
then turn the stem clockwise a few turns. This will allow
pressure to be sensed without restricting refrigerant flow.
Replace stem caps after system is opened to refrigerant
flow. Replace caps finger- -tight and tighten with wrench
an additional 1/12 turn.
NOTE: The gage port does not contain a Schrader core.
3. Close electrical disconnects to energize system.
4. Set room thermostat at desired temperature. Be sure set
point is below indoor ambient temperature.
5. Set room thermostat to COOL and fan control to ON or
AUTO mode, as desired. Operate unit for 15 minutes.
Check system refrigerant charge.
STEP 12 —Check Charge
UNIT CHARGE
Factory charge and charging methods are shown on unit
information plate. Charge Puron refrigerant units with cylinder in
upright position and a commercial- -type metering device in
manifold hose. Charge refrigerant into suction line.
NOTE: If subcooling charging conditions are not favorable,
charge must be weighed in accordance with unit rating plate, ±0.6
oz/ft. of 3/8- -in. liquid line above or below 15 ft., respectively.
Favorable conditions fall within the ranges given on the charging
chart on the outdoor unit plate.
NOTE: In longline applications, see Application Guideline for
special charging requirements.
EXAMPLE:
To calculate additional charge required for a 25 ft. line set:
25 ft. - - 15 ft. = 10 ft. X 0.6 oz/ft. = 6 oz. of additional charge.
COOLING ONLY PROCEDURE
This system requires charging by the subcooling method.
1. Operate unit a minimum of 10 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 4. 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.
MAJOR COMPONENTS
Control Board
The AC control board controls the following functions:
S Compressor contactor operation
S Outdoor fan motor operation
S Compressor external protection
S Pressure switch monitoring
S Time Delays
Field Connections
When used with a standard thermostat, it is recommended to use
3 thermostat control wires to be connected to R, Y and C. When
using 3 wires, all diagnostic and time delay features are enabled
(See Fig. 15).
When only 2 thermostat control wires are available, units
beginning with serial number 3006E and newer will function, but
some control features are lost. (See Fig. 16). With only 2 wires
connected, the circuit board will be powered down whenever
there is no call for cooling, and the following will result:
S Compressor time delay is reduced from 5 minutes to 10
seconds
S When the thermostat is not calling for cooling, the
amber status light will be off, and no diagnostics codes
will be available
S All system counters will be reset on each new call for
cooling
When using Evolution Communicating control, 4 wires are
required to be connected to the ABCD terminal (see Fig. 14)
Compressor Internal Relief
The compressor is protected by an internal pressure relief (IPR)
which relieves discharge gas into the compressor shell when
differential between suction and discharge pressure exceeds
550- -625 psi. The compressor is also protected by an internal
overload attached to motor windings.
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