Fan Motor; Control Fault; Brown Out Protection; 230V Line (Power Disconnect) Detection - Bryant 189BNV EVOLUTION Service Manual

as long as none of it has been removed during the cap
removal.
8. Reinstall compressor sound blanket making sure discharge
thermistor and compressor power harness are routed as they
were from the factory
Table 4—Variable Speed Compressor Resistance
(winding resistance at 70_F 20_F)
MODEL 288BNV / 189BNV (OHMs)
WINDING
13, 24B
Between
1.13
terminals
Between
terminal &
ground
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
and/or improper operation.
Do not use Meggar for measuring the winding resistance.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
and/or improper operation.
To maintain water integrity of the compressor fusite terminal
box, the two holes in outer ring need to be full of RTV sealant.

Fan Motor

If verification of proper operation is required for the fan motor
used in this unit, follow these steps:
1. Disconnect fan motor connector from control board.
2. Measure resistance between any 2 of the 3 leads present.
3. Compare measurement to values below
Fan Motor Resistance
Unit Size
13, 24B
25, 36, 37, 48, 49 (AC), 60

Control Fault

If the outdoor unit control board has failed, the control will flash
the appropriate fault code (see Table 6). The control board should
be replaced.
Brown- - Out Protection
If the line voltage is less than 187V for at least 4 seconds, the
Compressor and OD fan goes to 0 rpm. Compressor and fan
operation are not allowed until voltage is a minimum of 190V. The
control will flash the appropriate fault code (see Table 6).

230V Line (Power Disconnect) Detection

The control board senses the presence of absence of 230V through
inverter feedback. Voltage should present at all times when system
is in service regardless if system is running or standby. If there is
no 230V at the inverter when the indoor unit is powered with a
cooling or heating demand, the appropriate fault code is displayed
on UI (communicating only – see Fig. 38). If system is configured
with conventional heat pump thermostat (non- -communicating), no
fault code will be displayed on AOC board, nor will any status
LEDs be lit. Use multimeter to check for the presence of 230V in
this situation.
25 36 37, 48 49, 60
.59 .59 .37 .24
>1 mega
Resistance (Ohms)
21.2
11.1
High Pressure Switch Protection
The outdoor unit is equipped with a high pressure switch. If the
control senses the opening of a high pressure switch (open 600+/- -5
psig, close 470+/- -10 psig @77_F), it will respond as follows:
1. Display the appropriate fault code (see Table. 6).
2. After a 6 minute delay, if there is a call for cooling or heat-
ing and HPS is reset, the PEV opens for 150 seconds to
equalize system pressures. The compressor and fan will then
ramp to the next lower stage of operation until demand is
satisfied. The staging down and resetting to the highest
stage will end after 2 hours of accumulated operation with-
out further HPS trips.
3. A system malfunction will occur after repeated HPS faults
and the stages have reached the lowest level. This could
take five consecutive HPS trips if the first occurred in stage
5 demand or 1 HPS trip if in stage 1 demand.
4. In the event of a high- -pressure switch trip or high- -pressure
lockout, check the refrigerant charge, outdoor fan operation,
and outdoor coil (in cooling) for airflow restrictions, or in-
door airflow in heating.
Low Pressure Protection
The outdoor unit is equipped with low pressure transducer. If the
control senses a low pressure per the table below, it will respond as
follows:
Cooling Cool
Low mode
Pressure
Pressure resume
(No Op-
3 minute operation
eration)
operation begins
<= 33 > 43 <= 15
1. Display the appropriate error code on the status LED (see
Table 6).
2. If a demand persists after the 6- -minute delay and the
pressure has reached the operation level, then resume
operation. Reset the 6 minute timer, clear the displayed
error code and communicate cleared error to the User
Interface. Status LED reverts to operation code display.
3. If a demand persists after the 6- -minute delay but the
pressure has not recovered, turn off the ODF. If the pressure
recovers any time after the 6 minute delay, then resume
operation. Reset the 6 minute timer, clear the displayed
error code and communicate cleared error to the User
Interface. Status LED reverts to operation code display.
4. If a pressure drops below the NO- -operation level three (3)
consecutive times, then lock out operation for 4 hours and
flash the appropriate error code and communicate lockout
status to the User Interface. The trip counter will reset to
zero if 15 minutes of successful operation occurs before the
rd
3 trip is recorded. Record the low pressure lockout in the
historical data.
5. In the event of a low pressure trip or low pressure lockout,
check the refrigerant charge and indoor airflow (cooling)
and outdoor fan operation and outdoor coil in heating.

Suction Pressure Transducer (SPT)

If the accuracy of the transducer is questioned, the technician can
check it while it is attached to the AOC board. Connect a gage
manifold to the suction valve gage port fitting.
At the AOC board, with the wire harness receptacle exposing a
portion of the three pins on the AOC board, a DC voltmeter can
read the DC voltage between ground and supply (input) terminal.
Ensure that the input voltage is 5 VDC. Next, read the DC voltage
across the ground and output terminal. Record the output voltage.
The suction pressure that the pressure transducer is reading can be
calculated by taking the output voltage and subtracting 0.5 from it
then taking that difference and multiplying it by 50. Pressure
(psig) = 50.0 x (DCV out - - 0.5). For example, if the measured
voltage is 3.0 VDC: 50 X (3.0 - - 0.5) - - 50 X 2.5 = 125 psig. See
Fig. 35.
15
Heat
Low Heating Low
mode
Pressure
resume
5 minute
operation
operation
begins
<= 33 > 35