Stall Prevention During Deceleration Function - Omron VARISPEED E7 User Manual

Stall Prevention During Deceleration Function

This function automatically lengthens the deceleration time with respect to the DC-bus voltage to avoid over-
voltage tripping.
Related Parameters
Parameter
Number
E1-01 Input voltage setting
Stall prevention selection during deceleration func-
L3-04
tion selection
*1. Value for 200 V class Inverters are shown. For a 400 V class inverter the values have to be doubled.
Setting the Stall Prevention Selection During Deceleration (L3-04)
There are four different settings selectable for L3-04.
L3-04=0: This setting disables the stall prevention function during deceleration. The motor will be decelerated
using the time set in C1-02 (C1-04). If the load inertia is very high and an OV fault occurs during deceleration
a braking option has to be used or the deceleration time has to be lengthened.
L3-04=1: This setting enables the stall prevention during deceleration. The inverter tries to decelerate within
the set deceleration time. It also observes the DC bus voltage. If the DC bus voltage reaches the stall preven-
tion level the deceleration is stopped and the output frequency is held. When the DC bus voltage falls below
the stall prevention level the deceleration will be continued.
L3-04=2: This setting enables the stall prevention during deceleration. The deceleration time set as C1-
taken as reference. The function automatically tries to optimize the deceleration time by observing the DC bus
voltage and shortening the deceleration time. The function does not lengthen the deceleration time, i.e. if C1-
is set too short OV may occur.
Setting Example
An example of stall prevention during deceleration when L3-04 is set to 1 is shown below.
Output frequency
Fig 6.22 Stall Prevention During Deceleration Operation
Name
Deceleration time controlled to
prevent overvoltage
Deceleration time
(set value)
Acceleration and Deceleration Characteristics
Change
Setting Factory
during
Range Setting
Operation
155 to
200
No
*1
*1
VDC
255
0 to 2 1 No
Time
Access
Level
Q
A
is
6-19