When the last event/action has been executed, the
sequence starts over again from event [0]/action [0].
Illustration 5.4 shows an example with 4 event/actions:
130BA062.14
State 1
13-51.0
13-52.0
State 2
13-51.1
13-52.1
Start
event P13-01
State 3
13-51.2
13-52.2
State 4
13-51.3
13-52.3
Stop
event P13-02
Stop
event P13-02
Stop
event P13-02
Illustration 5.4 Order of Execution when 4 Events/Actions are
Programmed
Comparators
Comparators are used for comparing continuous variables
(output frequency, output current, analog input, and so on)
to xed preset values.
Par. 13-11
Comparator Operator
=
TRUE longer than.
. . .
. . .
Par. 13-10
Comparator Operand
Par. 13-12
Comparator Value
130BB672.10
Illustration 5.5 Comparators
Logic rules
Combine up to 3 boolean inputs (TRUE/FALSE inputs) from
timers, comparators, digital inputs, status bits, and events
using the logical operators AND, OR, and NOT.
. . .
. . .
. . .
. . .
Par. 13-43
Logic Rule Operator 2
Par. 13-41
Logic Rule Operator 1
Par. 13-40
Logic Rule Boolean 1
Par. 13-42
Logic Rule Boolean 2
Par. 13-44
Logic Rule Boolean 3
130BB673.10
Illustration 5.6 Logic Rules
5.2.12 Safe Torque O
The Safe Torque O (STO) function is used to stop the
drive in emergency stop situations.
For more information about Safe Torque O, including
installation and commissioning, refer to the Safe Torque O
Operating Guide.
Liability conditions
The customer is responsible for ensuring that personnel
know how to install and operate the safe torque o
function by:
•
Reading and understanding the safety regulations
concerning health, safety, and accident
prevention.
•
Understanding the generic and safety guidelines
provided in the Safe Torque O Operating Guide.
•
Having a good knowledge of the generic and
safety standards for the specic application.
5.3 Dynamic Braking Overview
Dynamic braking slows the motor using 1 of the following
methods:
•
AC brake
The brake energy is distributed in the motor by
changing the loss conditions in the motor
(parameter 2-10 Brake Function = [2]). The AC
brake function cannot be used in applications
with high cycling frequency since this situation
overheats the motor.
•
DC brake
An overmodulated DC current added to the AC
current works as an eddy current brake
(parameter 2-02 DC Braking Time ≠ 0 s).
•
Resistor brake
A brake IGBT keeps the overvoltage under a
certain threshold by directing the brake energy
from the motor to the connected brake resistor
(parameter 2-10 Brake Function = [1]). For more
information on selecting a brake resistor, see VLT
®
Brake Resistor MCE 101 Design Guide.
For drives equipped with the brake option, a brake IGBT
along with terminals 81(R-) and 82(R+) are included for
connecting an external brake resistor.
The function of the brake IGBT is to limit the voltage in the
DC link whenever the maximum voltage limit is exceeded.
It limits the voltage by switching the externally mounted
resistor across the DC bus to remove excess DC voltage
present on the bus capacitors.
External brake resistor placement has the advantages of
selecting the resistor based on application need,
dissipating the energy outside of the control panel, and
protecting the drive from overheating if the brake resistor
is overloaded.
Product Features Design Guide
MG38C202 Danfoss A/S © 01/2018 All rights reserved. 23
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