Siemens COMBIMASTER Reference Manual page 32

COMBIMASTER & MICROMASTER Integrated
REFERENCE MANUAL
Parameter Function
P074 • • • •
2
I t motor de-rating
P076 • • • •
Pulse frequency
P077
Control mode
P078 • • • •
Continuous boost (%)
P079 • • • •
Starting boost (%)
Siemens plc. 1999
© | G85139-H1731-U300-D2
Range
[Default]
0 - 1
0 = Disabled
[0]
1 = Enabled. Causes an F074 trip if the motor I
reaches its limit. The time taken to trip is dependent on the
difference between the overload current and the nominal motor
current rating stored in P083 - typically a 150% overload will
result in a switch-off in 1-2 minutes.
For safety-critical applications, it is recommended that a motor
PTC is used to protect the motor from overheating.
0 – 3 Sets the pulse frequency (from 8 to 16kHz). If silent
operation is not absolutely necessary, the losses in the
[0 or 2]
inverter can be reduced by selecting lower pulse
[2]
frequencies.
0 & 1 = 16 kHz (- Default for 230 V inverters)
2 & 3 = 8 kHz (- Default for 400V inverters).
Derating required and EMC performance is affected on
selection of non-default frequency
0- 3 Controls the relationship between the speed of the motor
and the voltage supplied by the inverter.
[0]
0 = Linear voltage/frequency.
1 = Flux current control(FCC)
2 = Quadratic voltage/frequency relationship.
This is suitable for centrifugal pumps and fans.
V
N
V
mains
V
N
3 = Linear voltage/frequency with energy saving. Output
voltage is reduced at low load (not recommended for
dynamic loads).
Operates continuously over the whole frequency range.
0 - 250
[50]
For many applications it is necessary to increase low
frequency torque. This parameter sets the start-up voltage
at 0 Hz to adjust the available torque for low frequency
operation. 100% setting will produce rated motor current at
low frequencies.
If P078 is set too high, overheating of the motor and/or an
overcurrent trip (F002) can occur.
0 - 250 For drives which require a high initial starting torque, it is
possible to set an additional current (added to the setting in
[0]
P078) during ramping. This is only effective during initial
start up and until the frequency setpoint is reached.
This increase is in addition to P078, but the total is limited
to 250%.
Description / Notes
0/1/3
2
f (P081)
N
2
t calculation
f
31