Operation mode

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)