The operation mode provides useful information for easy testing and debugging of the domestic hot water heat exchanger. This information is available as a parameter DISP-03 or the macro output "OperationMode".
The output operation mode must be connected to a multi-stage datapoint with the states as shown in the next table.
Since BACnet multi-stage points do not support the value "0", the operation mode value range starts from "1".
Table 13. Operation modes
DISP-02 OperationMode |
Operation mode |
Comment |
1 |
unoccupied period |
DHW_TempSp < SYS-01 |
2 |
occupied period - normal operation |
DHW_TempSp >= SYS-01 |
3 |
primary supply temp limitation active (has the minimum signal) |
primary supply temperature limitation control has the minimum signal |
4 |
primary return temp limitation active (has the minimum signal) |
primary return temperature limitation control has the minimum signal |
5 |
periodic valve opening during limitation control |
open the valve to avoid measuring standing water during limitation control, if the valve control signal = 0%. |
6 |
minimum pressure switch alarm |
alarm at the input “SecMinPressSw” |
7 |
||
8 |
||
9 |
system supply temperature setpoint failed |
“SecSupTemp” < “CalcDHWTempSp” –SST-06 for more than 600 sec after control start. |
10 |
legionella protection function active |
input “LegionellaActive” is active increases the return temperature setpoint |
11 |
legionella protection function failed |
secondary supply or circulation temperature sensors didn't reach the anti-legionella setpoint, within the time to reach legionella setpoint LEG-02 |
12 |
maximum temperature limitation by max. thermostat |
alarm at the input “MaxThermostat” |
13 |
||
14 |
maximum refill time exceeded |
refill failed after a minimum pressure alarm (6) |