Ionization Current Maintenance - Siemens LMS14 User Manual

Building Technologies Division

6.38.2 Ionization current maintenance

Function Ionization current maintenance is only available if limitation of the ionization
current is activated.
This function is to be activated by the heating expert by setting Fan speed ionization
current (7050) to a level above Required speed LF min (9525).
When the minimum fan speed limit exceeds this limit, a maintenance message is
delivered.
The maintenance limit for the fan speed lies between Required speed LF min (9525)
and Required speed HF max (9530).
The exact value must be defined by tests on a customer-specific basis.
The purpose of maintenance Message ionization current (7051) is to detect a slow drift
of the ionization current.
Fan speed ionization current (7050) is used for that purpose.
This parameter is greater than Required speed LF min (9525) and also greater than
Fan speed ionization current (7050), which occurs in normal operation.
If, due to ionization current drift, the value of Nmin rises above the value of Fan speed
ionization current (7050) (due to function → Ionization current limitation), a
maintenance message is delivered.
Since a maintenance message shall not be delivered the very first moment the value is
exceeded or, if exceeded, only once, 2 filters are used:

The filter acquires the period of time during which the value has been exceeded

The acquired period of time is reduced if both the current and the minimum fan
speed fall again below Fan speed ionization current (7050)

If this time exceeds 10 minutes, a maintenance message is output
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28.01.2015