Operating Instructions

SED2 VFD Operation & Maintenance Manual
150 Siemens Building Technologies, Inc.
Note: Useful for motors with high inertia loads.
Settings 1 to 3 search in both directions.
Settings 4 to 6 search only in direction of setpoint.
Flying start must be used in cases where the motor may still be turning (for example, after a short mains break) or
can be driven by the load. Otherwise, overcurrent trips will occur
P1202 Motor-current: Flying start
Min: 50 Def: 100 Max: 200
Level 3
Details: Defines search current used for flying start.
Value is in [%] based on rated motor current (P0305).
Note: Reducing the search current may improve performance for flying start if the inertia of the system is not very high.
P1203 Search rate: Flying start
Min: 50 Def: 100 Max: 200
Level 3
Details: Sets factor by which output frequency changes during flying start to synchronize with turning motor. Enter this
value in [%] relative to default time factor (which defines the initial gradient and influences time taken to search for
motor frequency). The search time is the time taken to search through all possible frequencies (between
[f_max+2*f_slip] and 0 Hz).
P1203=100% is defined as giving a rate of 2% of f_slip,nom/[ms].
P1203=200% would result in a rate of frequency change of 1% of f_slip,nom/[ms].
Example: For a motor with 50 Hz, 1350 rpm, 100% would produce a maximum search time of 600 ms. If the motor is
turning, the motor frequency is found in a shorter time.
Note: A higher value produces a flatter gradient and thus a longer search time.
A lower value has the opposite effect.
P1210 Automatic restart
Min: 0 Def: 1 Max: 5
Level 2
Enum: 0=Disabled
1 =Trip reset after power on: P1211 disabled
2 =Restart mains break; power on: P1211 disabled
3 =Restart after fault/mains break: P1211 enabled
4 =Restart after mains break: P1211 enabled
5 =Restart mains break/fault/power on: P1211 disabled
Dependency: Auto restart requires constant ON command (for example, via a digital input wire link).
Caution: Settings 2 to 5 can cause the motor to restart unexpectedly
Note: Flying start must be used in cases where the motor may still be turning (for example, after a short mains break) or
can be driven by the load (P1200).
P1211 Number of restart attempts
Min: 0 Def: 3 Max: 10
Level 3
P1212 Time to first restart
Min: 0 Def: 30 Max: 1000
Level 2