Appendix A - Troubleshooting - Carrier CRECOMZR101A00 Installation Instructions Manual

SYMPTOM
An alarm is displayed on Sensor, damper, or the whole working
the LCD system may not work properly
DAC LED is blinking RED Damper slippage
DAC LED is blinking 
Damper unplugged
RED quickly
Terminal ACT-FB is configured but
DAC LED is OFF
there is no available feedback signal
Shutoff SP setting error
Economizer controller
has no alarm, but the OA temp is too low
Free Cooling LED will
not turn on when the OA
seems to be suitable for
OA temp is too high or too humid
Free Cooling
No input power
Brownout
Economizer controller/
mechanical cooling is
Y1/Y2 signal is missing from the
not operating
thermostat
24 vac~ and 24 vac 
are incorrectly wired
Application file is damaged, operation
Firmware Update Failure is incorrect, and/or USB flash disk
does not work properly.
Free Cooling LED is solid Sensor, damper, or whole working
RED system may not work properly
Free Cooling LED is
Not economizing when it should
blinking RED
Incorrect controller
The password has changed from
password error on
default
mobile application
RS485 communication
RS485 signal or configuration error
failure
Sensor LED is blinking
Excess outdoor air
RED
Mixed Air (MA) sensor error
Outside Air (OA)/Return Air (RA)
Sensor LED is solid RED sensor error
Air temperature failure/fault
Sensor LED is OFF CO
Sensor LED is YELLOW Humidity sensor error
Wi-Fi/WLAN stick error or wrong user
Wi-Fi connection failure
name and password
APPENDIX A — TROUBLESHOOTING
Table A — Operating Issues and Concerns
REASON
sensor error
2
Check sensor, damper, or the whole working system following the detailed alarm
information.
Check whether the damper works properly.
Check whether the damper is connected.
Check whether the feedback signal is connected; check if ACT-FB is faulty.
Shutoff temperature and/or enthalpy set point is incorrectly set up. Consult an
HVAC professional to set up the shutoff set point correctly.
The OA temperature is too low; therefore, there is no cooling demand. This could
possibly enable anti-freeze protection.
In DIFF mode, even though OA temperature is lower than RA temperature, if both
OA and RA temperatures exceed the high limit, then Free Cooling turns off.
In Differential Enthalpy control mode, even though OA enthalpy is lower than RA
enthalpy, if both OA and RA enthalpy exceed the high limit, then Free Cooling turns
off.
Use a multi-meter to check whether there is 24 vac ± 25% (18-30 vac) at the
POWER terminals. If there is no voltage or if the voltage is significantly low, then
check the transformer output voltage at the RTU. If 24-v is not present at the
transformer secondary side, then check the primary line voltage to the transformer.
If the line voltage is not present at the transformer primary side, then check the
primary power to the RTU, fuses, circuit breaker, and so on.
If voltage is below 17-v, then the economizer controller may be in Brownout
Protection mode. This mode disables all of the relay outputs. When the power is
19 vac or higher, the economizer controller and RTU operate normally.
Mechanical cooling does not run until there is cooling demand (Y1/Y2 Active).
Check the wiring from Y1I and Y2I terminals to the commercial thermostat. 24-v
should be present between Y1I/Y2I and Y1O/Y2O respectively.
24 vac power supply has polarity when all devices are powered by the same 24 vac
transformer; reversing polarity may cause a short circuit that can damage the
system.
Follow the transformer polarity mark, check the wiring of 24-v~ (or G or 24-v+), and
ensure that they are tied to the same polar of 24 vac power supply; while checking
the wiring of  (or G0 or 24-v- or COM), ensure that they are all tied to another polar
of 24 vac power supply.
Reload a BIN file, restart the controller, update firmware following "Firmware
Update" on page 19, or change a USB flash disk. Contact service provider if failure
still exists.
Check sensor, damper, or the whole working system following the detailed alarm
information.
Check the whole economizer working system, such as the sensor, damper, and
thermostat.
Performing a factory reset on the controller will reset the password to OneBT.
Check wiring, configuration, Baud Rate (using mobile application), and other
network communication parameters.
Check the whole economizer working system, such as the sensor, damper, and
thermostat.
Check the MA sensor. It must be either a Type II NTC 10K or 0-10 vdc sensor.
Check the wiring and signal of the OA sensor. If in Differential (DIFF) mode, also
check the RA sensor. The following sensor signals are valid:
Type II NTC 10K or 0-10 vdc temperature.
0-10 vdc or 4-20 mA humidity.
Check the air temperature sensor signal. The valid signal must be Type II NTC 10K
or 0-10 vdc.
Check CO sensor connection, sensor signal (under range or over range), and
2
sensor signal type.
Check humidity sensor connection, sensor signal (under range or over range), and
sensor signal type.
Unplug and re-plug in the Wi-Fi/WLAN stick, enter a correct user name and
password, restart the controller, or replace the Wi-Fi/WLAN stick. If the Wi-Fi/
WLAN stick is POL903.00/100, then the default user name and password are
Siemens-WLAN-Stick and SIBPAdmin. DNS name is siemens.wlanstick. Contact
Application Engineering for information on this accessory.
30
SOLUTION