Specifications

Altivar
®
31 Adjustable Speed AC Drives
Functions
35
4/2005
© 2004–2005 Schneider Electric All Rights Reserved
Acceleration and deceleration ramp profile
This function gradually increases the output frequency, starting from a speed
reference and following either a linear ratio or a preset ratio.
• For applications such as material handling, packaging, and transporting
people: Using S ramps takes up mechanical play, eliminates jolts, and
limits non-following of speed during rapid transient operation of high
inertia machines.
• For pumping applications (installation with centrifugal pump and non-
return valve): Using Uramps controls valve closing more accurately.
Selecting linear, S, U, or customized profiles affects both the acceleration and
deceleration ramps.
Ramp switching
This function switches two acceleration or deceleration ramp times, which
are separately adjustable. It is enabled by a logic input, a frequency
threshold, or a combination of the two.
Ramp switching is suited to material handling with smooth starting and
approach, and to machines with fast steady-state speed correction.
S ramps U ramps Customized ramps
HSP: high speed
t1: ramp time set
t2: 0.6 x t1
The curve coefficient is fixed.
HSP: high speed
t1: ramp time set
t2: 0.5 x t1
The curve coefficient is fixed.
HSP: high speed
ACC: acceleration ramp 1 time
AC2: acceleration ramp 2 time
dEC: deceleration ramp 1 time
dE2: deceleration ramp 2 time
tA1: adjustable between 0 and 100% (of ACC or AC2)
tA2: adjustable between 0 and (100% – tA1)
(of ACC or AC2)
tA3: adjustable between 0 and 100% (of dEC or dE2)
tA4: adjustable between 0 and (100% – tA3)
(of dEC or dE2)
f (Hz) f (Hz)
HSP HSP
00t
t
t2
t1
t2
t1
563049
f
(H
z
)
HSP
0
t
t2
t1
f
(H
z
)
HSP
0
t
t2
t1
563050
f (Hz)
HSP
0t
tA1
ACC or AC2
f (Hz)
HSP
0
t
tA2
tA3
tA4
dEC or dE2
563051
t
t
f (Hz)
0
1
LI4 0
1
t
AC2
ACC
Forward
or
Reverse
dE2
dEC
Acceleration 1 (ACC) and
deceleration 1 (dEC):
– adjustment: 0.1 to 999.9 s
– factory setting: 3 s
Acceleration 2 (AC2) and
deceleration 2 (dE2):
– adjustment: 0.1 to 999.9 s
– factory setting: 5 s
HSP: high speed
HSP
Example of switching using logic input LI4
DF531555.eps
Courtesy of Steven Engineering, Inc.-230 Ryan Way, South San Francisco, CA 94080-6370-Main Office: [phone]-Outside Local Area: [phone]-www.stevenengineering.com