BHP16 Installation Instructions

506468-01 Page 17 of 24Issue 1946
Control Board Diagnostic LEDs
DS2
Green
DS1
Red
Condition / Code Possible Cause(s) Solution
O󰀨 Power problem
No power (24V) to board
terminals R & C or board
failure.
1
Check control transformer power (24V).
2
If power is available to board and LED(s) do not light,
replace board.
Simultaneous
SLOW ash
Normal operation
Unit operating normally or in
standby mode.
None required.
Alternating
SLOW ash
5-minute anti-short cycle
delay
Initial power up, safety trip,
end of room thermostat
demand.
None required (Jumper TEST pins to override)
Simultaneous
FAST ash
Ambient sensor problem
Sensor being detected open or shorted or out of temperature range. Board will revert
to time/temperature defrost operation. (System will still heat or cool)
Alternating
FAST ash
Coil sensor problem
Sensor being detected open or shorted or out of temperature range. Board will not
perform demand or time/temperature defrost operation. (System will still heat or cool)
On Circuit board failure
Indicates that board has internal component failure. Cycle 24V power to board. If
code does not clear, replace board.
Fault & Lockout Codes (Each fault adds 1 strike to that code’s counter; 5 strikes per code = LOCKOUT)
O󰀨
SLOW
ash
Low pressure fault
1. Restricted air ow over
indoor or outdoor coil.
2. Improper refrigerant
charge in system.
3. Improper metering device
installed or incorrect
operation of metering
device.
4. Incorrect or improper
sensor location or
connection to system.
1. Remove any blockages or restrictions from coils
and/or fans. Check indoor and outdoor fan motor
for proper current draws.
2. Check system charge using approach & sub-
cooling temperatures.
3. Check system operating pressures and compare
to unit charging charts.
4. Make sure all pressure switches and sensors
have secure connections to system to prevent
refrigerant leaks or errors in pressure and
temperature measurements.
O󰀨 On Low pressure LOCKOUT
SLOW
ash
O󰀨 High pressure fault
On O󰀨 High pressure LOCKOUT
SLOW
ash
On
Discharge line
temperature fault
This code detects shorted sensor or high discharge temperatures. If the discharge
line temperature exceeds a temperature of 300°F (148°C) during compressor
operation, the board will de-energize the compressor contactor output (and
the defrost output if active). The compressor will remain o󰀨 until the discharge
temperature has dropped below 225°F (107°C).
FAST
ash
On
Discharge Line
Temperature LOCKOUT
O󰀨
FAST
ash
Discharge sensor fault
The board detects open sensor or out of temperature sensor range. This fault is
detected by allowing the unit to run for 90 seconds before checking sensor resistance.
If the sensor resistance is not within range after 90 seconds, the board will count one
fault. After 5 faults, the board will lockout.
FAST
ash
O󰀨
Discharge sensor
LOCKOUT
Table 6. Control Board Diagnostic LEDs