ABB ACS850 Firmware Manual page 38

38 Program features
Operation time scheme
The simplified time scheme below illustrates the operation of the brake control
function.
Start cmd
Ramp input
Modulating
Ref_Running
Brake open
cmd
Ramp output
Torque ref
1
T Start torque at brake release (parameter
s
T Stored torque value at brake close (signal
mem
t Motor magnetising delay
md
t Brake open delay (parameter
od
n Brake close speed (parameter
cs
t Brake close command delay (parameter
ccd
t Brake close delay (parameter
cd
Example
The figure below shows a brake control application example.
WARNING! Make sure that the machinery into which the drive with brake
control function is integrated fulfils the personnel safety regulations. Note
that the frequency converter (a Complete Drive Module or a Basic Drive
Module, as defined in IEC 61800-2), is not considered as a safety device
mentioned in the European Machinery Directive and related harmonised
T
s
2 3 4
t t
md od
42.03 Open
42.04 Close
n
5
42.08 Brake open
03.15 Brake torq
delay)
42.05 Close speed)
42.06 Close cmd
delay)
t
ccd
cs
T
mem
6
t
cd
torq)
mem)
delay)
7
Time