Soft Start Methods; Constant Current - Danfoss VLT MCD 600 Operating Manual

Operating Guide | VLT® Soft Starter MCD 600
Application
Crusher - cone
Crusher - jaw
Crusher - rotary
Debarker
Fan - axial (damped)
Fan - axial (undamped)
Fan - centrifugal (damped)
Fan - centrifugal (undam-
ped)
Fan - high pressure
Mill - ball
Mill - hammer
Pump - bore
Pump - centrifugal
Pump - hydraulic
Pump - positive displace-
ment
Pump - submersible
Saw - bandsaw
Saw - circular
Shredder

9.8 Soft Start Methods

9.8.1 Constant Current

Constant current is the traditional form of soft starting, which raises the current from 0 to a specified level and keeps the current stable
at that level until the motor has accelerated.
Constant current starting is ideal for applications where the start current must be kept below a particular level.
Danfoss A/S © 2018.10
Start mode Start
ramp
time [s]
Constant current 1
Constant current 1
Constant current 1
Constant current 1
Constant current 1
Constant current 1
Constant current 1
Constant current 1
Constant current 1
Constant current 1
Constant current 1
Adaptive control (ear- 3
ly acceleration)
Adaptive control (ear- 10
ly acceleration)
Constant current 2
Adaptive control (con- 10
stant acceleration)
Adaptive control (ear- 5
ly acceleration)
Constant current 1
Constant current 1
Constant current 1
Initial cur- Current
rent limit
(%FLC) (%FLC)
200 350
200 450
200 400
200 350
200 350
200 450
200 350
200 450
200 450
200 450
200 450
n/a 500
n/a 500
200 350
n/a 400
n/a 500
200 450
200 350
200 450
AQ262141844215en-000202 / 175R1174 | 57
Operation
Stop mode Stop time
[s]
Coast to stop n/a
Coast to stop n/a
Coast to stop n/a
Coast to stop n/a
Coast to stop n/a
Coast to stop n/a
Coast to stop n/a
Coast to stop n/a
Coast to stop n/a
Coast to stop n/a
Coast to stop n/a
Adaptive control 3
(late deceleration)
Adaptive control 15
(late deceleration)
Coast to stop n/a
Adaptive control 10
(constant decelera-
tion)
Adaptive control 5
(late deceleration)
Coast to stop n/a
Coast to stop n/a
Coast to stop n/a