Overheat Protection of Heat Generators

In case of excessive heat in the primary heating system, it is possible to dissipate this heat into the secondary heat consuming circuits. Primary heating generators can generate a heat override signal. In this case the DHWS setpoint will be increased by the value, as defined by the parameter SYS-02.

The maximum calculated DHW setpoint will be limited by anti-legionella setpoint LEG-01.

If the heat override signal becomes zero again, the DHWS setpoint will be ramped down to its normal value. The ramp down is defined as a decrease per minute defined by the parameter SYS-03.

The next figure shows the relation between the calculated setpoint and the heat override function.

The circulation pump will run during overheat protection staring without delay if the parameter SEP-04 = 3 or 4.

Fig. 6.   Overheat Protection

Table 17.   Parameter List

Description

Range

Default

Units

LEG-01: anti-legionella setpoint

0...90

70

°C

SEP-04: circulation pump during overheat protection

0; 1 = disable

2 = enabled if “MaxThermostat” = 1

3 = enabled if “OverheatProt” = 1

4 = enabled if “MaxThermostat” = 1 or if “OverheatProt” = 1

0..4

0

-

SYS-02: setpoint increase at OverheatProt; 0 = disable

0...30

10

K

SYS-03: setpoint decrease/ minute after a Heat_Override

1…100

5

K