Reaction
, trips in Safe Torque Off or Safe Stop 1 if
an overspeed occurs
•
SLS with ramp: Limits the motor speed to a set
point and, depending on the setting of
42-52 Fail
Safe Reaction
, trips in Safe Torque Off or Safe
Stop 1, if an overspeed occurs
The Safe Limited Speed is given as speed limit in
42-51 Speed Limit
. The value for the cut-off speed partly
depends on the motor that is being used. A suggested
value from MCT 10 Set-up Software calculates a value for
which Danfoss guarantees functionality. This value is called
delta speed limit and is added to the selected speed limit
and suggested as value in
42-50 Cut Off Speed
.
3.5.5.1 SLS without Ramp
The safety function Safely Limited Speed monitors whether
a specified velocity value is exceeded since it was activated
via DI1 or DI2. The function is active until the selected
input has been put to high again.
If 2 Safe Speed limits must be monitored, set one of the 2
Safe Digital Inputs DI1 or DI2 in
42-20 Safe Function
to SLS-
a or SLS-b. Then select the input type under
42-21 Type
.
The cut-off speed represents the maximum allowed
frequency of the actual motor frequency. If the motor
frequency accelerates above that value, the safety option
enters external fault selected (STO or SS1 Ramp), and the
error is given. The frequency value at which a shutdown is
realised should be parameterised in
42-50 Cut Off Speed
.
Parameter
Unit Range
Default
42-50 Cut Off Speed RPM 120-10000 RPM
270 RPM
42-51 Speed Limit
RPM 1-9999 RPM
150 RPM
42-52 Fail Safe
Reaction
n/a Safe Torque Off/Safe
Stop 1
Safe Torque
Off
Table 3.4 Parameters for SLS without Ramp
time
1
2
4
5
3
6
fr
equen
cy
130BC324.10
A
B
A
Actual frequency
B
SLS limit
1
SLS is activated
2
42-51 Speed Limit
3
42-50 Cut Off Speed
4
Delta speed limit
5
Activation of failure function set in
42-52 Fail Safe Reaction
6
Fixed value of 120 RPM in
42-19 Zero Speed Limit
Illustration 3.11 SLS without Ramp
If speed exceeds the limit,
42-52 Fail Safe Reaction
is
activated. The safety function can either be Safe Torque
Off or SS1 Ramp Time. Safe Stop 1 can only be triggered
as error response if one Safe Stop 1 function has been set
as Safe Stop 1 with ramp time function, set in
42-40 Type
.
Functions and System Overvi...
Operating Instructions
MG34W302
Danfoss A/S © Rev. 2014-02-11 All rights reserved.
19
3
3
Summary of Contents for VLT Safety Option MCB 150
Page 2: ......
