Siemens AVS75.39 Series User Manual page 101

Temperature
differential
Temperature differential
max.
Temperature differential
nominal
Siemens
Building Technologies
The limit thermostat is activated when:
The boiler temperature (TKx) exceeds the TR setpoint
There is no boiler temperature signal, e.g. no signal from the sensor due to a
short-circuit
Release of the limit thermostat is deactivated when:
The boiler temperature drops by half the boiler's switching differential (SDK/2),
but at least 2 K
The electronic limit thermostat is integrated in burner relay control in a way that
relays K4/K5 will immediately be deenergized when the limit thermostat becomes
active (independent of control, relay test, and manual control). It is only during the
STB (safety limit thermostat) test that the electronic limit thermostat does not
become active.
Line no. Operating line
2316 Temperature differential max.
2317 Temperature differential nominal
The maximum boiler switch-off point is calculated using the present boiler return
temperature (B7) plus the set maximum differential.
The function can be deactivated.
Setpoint for boiler pump speed by differential.
The setting only acts on variable speed boiler pumps.
User manual RVS43.345
The settings in detail
101 / 239
CE1U2354en_021
2013-09-02