Honeywell TC500A User Manual

62 31-00400M-01 | Rev10-20
5 - MANAGING ALARMS
Internal Humidity Sensor
Failure
Onboard humidity sensor fault is
detected
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.
High
(Action 2)/
Medium
(Action 1)
Internal Proximity Sensor
Failure
Onboard proximity sensor (I2C bus)
fault is detected
The thermostat is the same as that
no proximity sensor is configured.
Medium
CO2 sensor failure alarm
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. 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.
High
(failure)/
Medium (out
of range)
Outdoor air sensor failure
alarm
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. 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.
High
(failure)/
Medium (out
of range)
Mixed air sensor failure
alarm
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. 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.
High
(failure)/
Medium (out
of range)
Discharge air sensor
failure alarm
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)
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.
High
(failure)/
Medium (out
of range)
Space Temperature out
of range alarm
Space temperature outside of range (SA
sensor<35F or SA sensor >125F). (No
matter which sensor act as space
temperature)
If the sensor is used to control loop
and network temp are available the
thermostat will just generate an
alarm.
Medium
Alarm Trigger Scenario Action Level

Honeywell TC500A Specifications

General

Brand	Honeywell
Model	TC500A
Category	Thermostat
Language	English