Honeywell Smartronic70 T9275A1002 User Manual page 11

Main Application
HX
AO
DO
Opened
Heating mode
100%
50%
0%
Closed
Heating setpoint
EC AP MKT
T
AI
DI
Alarming setpoint
Confidential and Proprietary
4. Heating Exchanger
• Steam or hot water heating
exchanger temperature limit control
– Heating is modulating output and
proportional to measured
temperature
– Heating setpoint is in the mid of
proportional band
– The temperature limit setpoint is
separate from the heating setpoint
– If the measured temperature is over
than temperature limit, the system
alarm is on
• Emergency Interlock
Alarm
– Under normal status, DI is closed. If
on
emergency happens, DI open. The
controller will reset all output, then
cut off the power.
– The controller only can be restarted
Temperature increase
by manual operation
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