Step 12 - Check Charge - Bryant 180CNV024 Installation Instructions Manual

Outdoor Fan Motor Operation
The outdoor unit control (Fig. 9) energizes outdoor fan anytime
compressor is operating as needed during low- -ambient cooling
operation. The outdoor fan remains energized if a pressure switch
opens or compressor scroll over temperature should occur. This
OD fan is an ECM motor which operates at varying speeds
depending on the ambient and the demand.
Time Delays
The unit time delays include:
S Five minute time delay to start cooling operation when there is a
call from the wall control. To bypass this feature, momentarily
short and release Forced Defrost pins.
S Five minute compressor re- -cycle delay on return from a
brown- -out condition.
S See Tab le 7 for other delay information.
General Information
Evolution Controlled low ambient cooling:
This unit is capable of low ambient cooling down to 0_F
(- -17.8_C) with Low Ambient enabled on the Evolution wall
control. A low ambient kit is not required.
The Evolution Control provides an automatic evaporator coil
freeze protection algorithm that eliminates the need for an
evaporator freeze thermostat. The only accessory that may be
required is wind baffles in locations which are likely to experience
cross winds in excess of 5 miles an hour. This generally occurs
only on roof and open area applications.
Low ambient cooling must be enabled in the wall control setup.
The outdoor unit fan will cycle on and off based on outdoor coil
temperature, outdoor air temperature, and suction pressure
measurements to keep the compressor running at the proper
conditions.
Utility Interface With Evolution Wall Control
The utility curtailment relay should be wired between the two
UTIL connections on the control board for this Evolution
Communicating System (see Fig. 16). This input allows a power
utility device to interrupt compressor operation during peak load
periods. When the utility sends a signal to shut the system down,
the User Interface will display, "Curtailment Active". See wall
control installation instructions for setup details.
Communication and Status Function Lights
Evolution Control, Green Communications (COMM)Light
A green LED (COMM light) on the outdoor board (see Fig. 9)
indicates successful communication with the other system
products. The green LED will remain OFF until communication is
established. Once a valid command is received, the green LED will
turn ON continuously. If no communication is received within 2
minutes, the LED will be turned OFF until the next valid
communication.
Amber Status Light
Amber colored STATUS light indicates operation and error status.
See Table 7 for definitions.
S Two minute time delay to return to standby operation from last
valid communication.
S One minute time delay of outdoor fan at termination of cooling
mode when outdoor ambient is greater than or equal to 100_F
(37.8_C).
STATUS
LED
COMM
LED
Fig. 9 - - Variable Speed Control Board
Step 12 — Check Charge
Charge in CHARGING mode
Factory charge amount and desired subcooling are shown in the
user interface (UI). To properly check or adjust charge, conditions
must be favorable for subcooling charging in cooling mode.
Favorable conditions exist when the outdoor temperature is
between 65_F and 100_F (18_C and 38_C), and the indoor
temperature is between 70_F and 80_F (21_C and 27_C). If the
temperatures are outside of these ranges, weigh- -in charge only. If
confirmation is needed return and check subcooling when the
temperatures are within the desired range.
Charging Procedure: Unit is factory charged for 15ft (4.57 m) of
lineset and for smallest rated indoor coil combinations. If any
refrigerant charge adjustment is required based on the indoor coil
combination and the line set length input, the wall control will
calculate and display the target subcooling and the amount of
additional charge to be added. Therefore wall control is the source
of information for charging the system correctly. Refrigerant
charge adjustment amount for adding or removing 0.6 oz/ft (17.74
g/m) of 3/8 liquid line above or below 15ft (4.57 m) respectively,
and an additional amount of refrigerant charge adjustment (2 lbs)
for a large ID coil if required, is calculated and displayed by the
wall control.
Perform a final charge check when OD is between 65F (18C)
and 100F (38C).
If the range is acceptable, go to the CHARGING screen on the wall
control. Set the wall control to check the charge in cooling mode.
Allow system to operate in cooling mode for the stabilization
period as indicated on the wall control. Once conditions are
indicated as favorable and stable by the wall control, check the
system charge by subcooling method. Compare the subcooling
taken at the liquid service valve to the subcooling target (target
service valve subcool) listed on the charging screen.
refrigerant if the subcooling is low and remove charge if
subcooling is high. Tolerance should be 2F.
If any adjustment is necessary, add or remove the charge slowly
(no greater than 0.5 lb per minute) and allow system to operate for
15 minutes to stabilize before declaring a properly charged system.
The use of a commercial charge metering device (restrictor) such as
Imperial liquid low side charger model 535- -C or Watsco
ChargeFaster model CH200 is recommended when adding
refrigerant to an operating system. This prevents potential damage
of liquid slugging of the compressor and allows the subcooling to
stabilize quicker.
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