Watson-Marlow MM440 - Manual (Page 242)

3 Functions Issue 10/06
MICROMASTER 440 Operating Instructions
242 6SE6400-5AW00-0BP0
3.23.1.5 Current limiting (Imax controller)
Parameter range: P1340 – P1346
r0056 bit 13
Warnings A0501
Faults F0001
Function chart number:
FP6100
In the V/f characteristic mode, the drive inverter has a current limiting controller in
order to avoid overload conditions (Imax controller, refer to Fig. 3-100). This
controller protects the drive inverter and the motor against continuous overload by
automatically reducing the drive inverter output frequency by f
Imax
(r1343) or the
drive converter output voltage by V
Imax
(r1344). By either reducing the frequency or
voltage, the stressing on the drive inverter is reduced and it is protected against
continuous overload and damage.
Imax controller setpoint
+
?
r1343
CO:Imax ctrl Foutp
r1344
CO:Imax ctrl Voutp
Current feedback
r0067
CO: Outp cur limit [A]
r0068
CO: Output current [A]
Motor ovl fact [%]
10.0 ... 400.0 [%]
P0640.D (150.0)
Motor temperatur
Inverter temperatur
i
2 t inverter
Motor ovl fact [%]
10.0 ... 400.0 [%]
P0640.D (150.0)
Imax ctrl prp gain
0.000 ... 5.499
P1345.D (0.250)
Kp Tn
Kp Tn
Imax ctrl int time
0.000 ... 50.000 [s]
P1346.D (0.300)
Imax ctrl prp gain
0.000 ... 0.499
P1340.D (0.000)
Imax ctrl int time
0.000 ... 50.000 [s]
P1346.D (0.300)
U
I_max
f
I_max
Fig. 3-100 Imax controller
NOTE
The drive inverter load is only reduced when the frequency is reduced if the load
decreases at lower speeds (e.g. square-law torque – speed characteristic of the
driven load).