Honeywell TC500A User Manual page 62

5 - MANAGING ALARMS
Alarm
Internal Humidity Sensor
Failure
Internal Proximity Sensor
Failure
CO2 sensor failure alarm
Outdoor air sensor failure
alarm
Mixed air sensor failure
alarm
Discharge air sensor
failure alarm
Space Temperature out
of range alarm
62
Trigger Scenario
Onboard humidity sensor fault is
detected
Onboard proximity sensor (I2C bus)
fault is detected
1. Open/short limit is detected on
CO2 sensor (UI1/UI2/UIO1/UIO2)
2. CO2 outside of range(CO2 < 0ppm
or DA sensor > 2000ppm)
1. Open/short limit is detected on
outdoor air sensor(UI1/UI2/UIO1/
UIO2)
2. OAT outside of range (OA sensor <
-40F or OA sensor > 150F)
1. Open/short limit is detected on
mixed air sensor (UI1/UI2/UIO1/
UIO2)
2. MAT outside of range: (MA sensor <
40F or MA sensor > 120F)
1. DAT sensor fault: Open/short limit
is detected on Discharge air sensor
(UI1/UI2/UIO1/UIO2)
2. DAT outside of range: (DA sensor <
35F or DA sensor > 165F)
Space temperature outside of range (SA
sensor < 35F or SA sensor >125F). (No
matter which sensor act as space
temperature)
Action
1.If the sensor is used to control
loop and network humidity space
sensors are available, the
thermostat will generate an alarm
2.If network temp/humidity space
sensors are unavailable, the
application shall disable all control
functions (E.g Humidity control for
humidification or dehumidification)
associated with the failed sensor.
The thermostat is the same as that
no proximity sensor is configured.
1. The application shall disable all
control functions associated
with the failed sensor; i.e. it will
react as if the sensor was not
configured.
2. CO2 out of range: Will not
disable control function, check
equipment for proper
operation.
1. The application shall disable all
control functions associated
with the failed sensor; i.e. it will
react as if the sensor was not
configured.
2. OAT out of range: Will not
disable control function, check
equipment for proper
operation.
1. The application shall disable all
control functions associated
with the failed sensor; i.e. it will
react as if the sensor was not
configured.
2. MAT out of range: will not
disable control function, Check
equipment for proper
operation.
1. DAT sensor fault: The
application shall disable all
control functions associated
with the failed sensor; i.e. it will
react as if the sensor was not
configured.
2. DAT out of range: Check
equipment for proper
operation.
If the sensor is used to control loop
and network temp are available the
thermostat will just generate an
alarm.
31-00400M-01 | Rev10-20
Level
High
(Action 2)/
Medium
(Action 1)
Medium
High
(failure)/
Medium (out
of range)
High
(failure)/
Medium (out
of range)
High
(failure)/
Medium (out
of range)
High
(failure)/
Medium (out
of range)
Medium