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31-00400M-01 | Rev10-20
61
MANAGING ALARMS
Managing Alarms
Table 16
Managing Alarms
Alarm
Trigger Scenario
Action
Level
Proof of Air Flow Alarm
(fan state)
An input (such as a current switch or
differential pressure switch) shall be
available to monitor proof of air flow in
the Rooftop Unit. When configured, the
control will monitor this digital input
once per second.
If the fan should be on, but it is not on, it
should generate an alarm and disable
stages. For example, if the stage should
be on, then digital input indicates no air
flow for 10 consecutive seconds.
Interlock stage: the control shuts
down heating and cooling outputs
and will continue to try to restart the
fan.
Alarm indicator is displayed.
High
Space Freeze Protection
Alarm
The frost alarm shall occur if space
temperature drops below 42.8F (6C)
even when the controller is in manual
mode, night purge mode, or pressurize/
depressurize.
No frost alarm shall occur if the
controller is disabled, in test mode, or in
some higher priority mode as defined
by the application.
The alarm shall be generated within
2 minutes of the temperature
sensor going below the frost
setpoint.
High
Proof of water flow Alarm
Heat pump proof of water is for water
source heat pumps only and needs
extra configuration (water flow
detector).
If the stage should be on, then the input
indicates loss of water flow in a Heat
pump application.
Interlock stage: The controller shall
disable the heat pump compressor.
High
Wi-Fi Network Not
Configured
If user selects Wi-Fi as the means of
communication, but the thermostat
isn't configured to join Wi-Fi network
Wi-Fi alarm is displayed on home
screen.
Medium
Wi-Fi Connection Lost
If user selects Wi-Fi as the means of
communication, and Thermostat lost
Wi-Fi connection with Gateway
Wi-Fi alarm is displayed on home
screen.
Low
Unknown Time
Thermostat has been powered off for a
long time thus RTC time is lost
Prompt user to set date/time
Medium
Internal Temperature
Sensor Failure
Onboard temp. sensor fault is detected
1.If the sensor is used to control
loop and network temp/humidity
space sensors are available, the
thermostat will generate an alarm
2.If the sensor is used to control
loop and network temp/humidity
space sensors are unavailable,
The application shall shut down all
output control of Heating and
Cooling equipment. The fan shall
remain under normal control.
High
(Action 2)/
Medium
(Action 1)
Содержание TC500A
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