Filling/Flow Supervision - Siemens LMS14 User Manual

Pressure switch
shutdown
Flow switch shutdown
Building Technologies Division

6.11.24 Filling/flow supervision

Line no. Operating line
2500 Pressure switch shutdown
Start prevention
Lockout position
This function checks the static water pressure with the help of the pressure switch.
The response in the event of insufficient static water pressure (contact open) can be
parameterized. Depending on parameter Pressure switch shutdown (2500), a change
to start prevention or lockout is made, including the respective diagnostics.
Warning!
Start prevention/lockout via this input is not implemented as a safety-related
function.
A water pressure switch whose contacts are closed releases immediately burner control
startup and control of the pumps. If the contacts of the pressure switch are open, start
prevention or lockout is triggered only when the set Min on time switch (2504) has
elapsed.
Caution!
If the value parameterized for Min on time switch (2504) is too small, error
detection may be wrong. The OEM is responsible for making certain that the
values set for the respective plant are correct.
To prevent the pump from running dry, pump control is disabled also.
When the water pressure rises again so that the contacts of the pressure switch close,
start prevention – if previously triggered – is automatically canceled and pump control is
released again.
Note!
With manual control, the pump cannot be deactivated, due to fixed control of the
actuators.
For this reason, manual control is ended in this case.
Line no. Operating line
2502 Flow switch shutdown
Start prevention
Lockout position
Using the boiler flow switch, this function checks if there is flow – and also sufficient
flow – through the primary heat exchanger.
Note!
For this reason, the contact may be evaluated only if, in the case of a heat request,
there is flow through the primary heat exchanger; as a result, the boiler flow switch is
not actively checked with the BwDl2 instantaneous water heater system and the
DHW function.
The response in the case of insufficient flow (contact open) can be parameterized.
Depending on parameter Flow switch shutdown (2502), a change to start prevention or
lockout is made, including the respective diagnostics.
Warning!
Start prevention/lockout via this input is not implemented as a safety-related
function.
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CC1U7471en
07.05.2014