Siemens AVS75.39 Series User Manual page 97

Overtemperature
protection
Pump overrun time
Minimum limitation of
the boiler temperature
Protective start-up
Optimum start control.
Siemens
Building Technologies
Line no. Operating line
2250 Pump overrun time
If the first burner stage is switched off, or if the boiler request becomes invalid, a
forced signal will be delivered during the parameterized pump overrun time.
Consumer pumps do not switch off during the period of time such a forced signal is
active.
Line no. Operating line
2260 Prot boil startup consumers
2261 Prot boil startup boil pump
2262 Optimum start control
The protective boiler start-up accelerates boiler boost heating below the boiler
minimum temperature by switching off, reducing the consumer load, depending on
hydraulic possibilities, or keeping the boiler pump turned off.
For the switched on function (Graphic 1, 2), the controller calculates, based on
boiler temperature gradients, the burner switch-on point to keep from dropping
below the minimum boiler temperature.
When the function is deactivated (graph 3), the controller will switch the burner on
at TKmin.
With optimum burner start control and about 35% load
80
70
60
50
40
30
20
13:00
With optimum burner start control and about 65% load
80
70
60
50
40
30
20
13:00
User manual RVS43.345
The settings in detail
13:30
13:30
TKx
TKmin
ON
OFF
14:00
TKx
TKmin
ON
OFF
14:00
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CE1U2354en_021
2013-09-02