After controller start, the secondary supply temperature failed alarm will be suppressed for a time defined by the parameter SYS-02. An alarm will be generated at the output "HE_Failure" if the secondary supply temperature drops below the calculated P-band, defined by parameter SST-06, for more than 600 sec (fixed value). This alarm can be reset by the input "Reset".
In case of manual reset and a secondary supply temperature failed alarm, the temperature control of the heat exchanger will be stopped until the alarm is reset by the input "Reset".
In case of automatic reset and a secondary supply temperature failed alarm, the temperature control of the heat exchanger continues until the system supply temperature has reached the target setpoint "CalcSSTempSp".
NOTE: |
To disable this alarm function, set parameter SYS-02 to "0". |
Programming Hint
The alarm "HE_Failure" can be used to enable a spare boiler which must be released in case of emergency only. The alarm can be reset manually or automatically as defined by parameter SYS-03.
Table 14. Parameter List
Description |
Value Range |
Default Value |
Unit |
SST-06: P-band SST control |
1...1000 |
20 |
K |
SYS-02: HE_Failure enable after release |
0...3600 |
1800 |
sec |
SYS-03: automatic/ manual reset; 0 = auto |
0 /1 |
0 |
- |