Diagnostic Leds; Control Board Led Alarms - Carrier 50EJ Installation, Start-Up And Service Instructions Manual

Diagnostic LEDs (Light-Emitting Diodes) —
are 3 LEDs (red, yellow, and green) on the lower right hand
side of the control board. The red light is used to check
unit operation and alarms. A constant pulse is normal unit
operation. A series of quick blinks indicates an alarm. Refer
LED ERROR
BLINKS CODE
1
2 HF-13
3 HF-14
4 HF-15
5 HF-05
6 HF-06
7 HF-03
8 HF-12
9 SE-05
10 HF-16
11 HF-17
LEGEND
DIP — Dual In-Line Package
LED — Light-Emitting Diode
VAV — Variable Air Volume
There
Table 20 — Control Board LED Alarms
DESCRIPTION
Normal Operation
Compressor 1 Safety
Compressor 2 Safety
Thermostat Failure
SAT Thermistor Failure
OAT Thermistor Failure
Space Temp. Sen. Failure
RAT Thermistor Failure
Loss of Communications
with Expansion board
Control Board Failure
Expansion Board Failure
to Table 20 below for a description of alarms. The yellow
LED blinks during transmission with the CCN (Carrier Com-
fort Network). The green LED blinks during transmission
with the expansion board.
TROUBLESHOOTING
COMMENTS
The expansion board and control board flash the red LED in one-
second intervals when the board is operating properly.
The high or low pressure safety switch for compressor no. 1 has
opened for 3 seconds. The error will be cleared and compressor
no. 1 will be allowed to turn on in 15 minutes. If the safeties have
been tripped 3 times in 90 minutes, compressor no. 1 will be
locked out until the control board has been manually reset.
The high or low pressure safety switch for compressor no. 2 has
opened for 3 seconds. The error will be cleared and compressor
no. 2 will be allowed to turn on in 15 minutes. If the safeties have
been tripped 3 times in 90 minutes, compressor no. 2 will be
locked out until the control board has been manually reset.
The thermostat is calling for both heating and cooling at the
same time. The unit will operate on a first call basis and will auto-
matically reset.
The supply-air temperature (SAT) sensor has failed. First check for
wiring errors, then replace sensor.
The outside-air temperature (OAT) sensor has failed. First check
for wiring errors, then replace sensor.
The space temperature sensor has failed. First check for wiring
errors, then replace sensor.
The return-air temperature (RAT) sensor has failed. Ensure that
the unit is a VAV unit. If NOT a VAV unit set DIP switch position 1
to the closed position and reset power. Then check for wiring
errors. Finally, replace sensor.
Communications between the expansion board and the control
board have been interrupted. Ensure that an expansion board
is installed and wired using the wire harness supplied with the
expansion module. If an expansion board is not used ensure that
DIP switch position 3 is in the closed position, and reset power.
Generated when hardware has failed on control board. Replace
the control board.
Generated when hardware has failed on the expansion board.
Replace the expansion board.
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