Safety Function - Sto (=Safe Torque Off); General Description; Important Terms And Explanations - Parker Compax3 Operating Instructions Manual

Parker EME
3.10

Safety function - STO (=safe torque off)

In this chapter you can read about:

General Description ......................................................................................................... 77

STO (= safe torque off) with Compax3S .......................................................................... 80
STO (= safe torque off) with Compax3m (Option S1) ....................................................... 88
3.10.1. General Description
In this chapter you can read about:

Important terms and explanations ................................................................................... 77

Intended use ................................................................................................................... 78
Advantages of using the "safe torque off" safety function. ............................................... 78
Devices with the STO (=safe torque off) safety function .................................................. 79
Term
Safety category 3 in accordance
with EN ISO 13849-1
"Safe torque off"
or abbreviated:
STO=Safe torque off
Start inhibitor
Stop categories according to EN60204-1 (9.2.2)
Stop
Safety function
category
0 Safe torque off
(STO)
1 Safe stop 1
(SS1)
2 Safe stop 2
(SS2)
The present documentation assumes a basic knowledge of our drive controllers as
well as an understanding of safety-oriented machine design. References to
standards and other regulations are only rudimentarily expressed.
For complementary information, we recommend the respective technical literature.
3.10.1.1 Important terms and explanations
Explanation
Definition according to standard:
Circuit with safety function against individual errors.
Some, but not all errors are detected.
An accumulation of errors may lead to a loss of the safety function.
The remaining risk is accepted.
The determination of the safety category required for an application (risk analysis) lies within the
responsibility of the machine manufacturer.
It can take place according to the method described in EN ISO 13849-1, appendix A.
With the "safe torque off", the energy supply of the drive is safely interrupted according to EN
1037, paragraph 4.1.
The drive is not to be able to produce a torque and thus dangerous movements (see EN 1037,
paragraph 5.3.1.3).
The standstill position must not be monitored.
If an external force effect, e.g. a drop of hanging loads, is possible with the "safe torque off",
additional measures to safely prevent those must be provided (e.g. additional mechanical brakes).
The following measures are appropriate for a "safe torque off":
Contactor between mains and drive system (mains contactor)
Contactor between power section and motor (motor contactor)
Safe blocking of the power semiconductor control (start inhibitor)
Safe blocking of the power semiconductor control.
With the aid of this function, you can obtain a "safe torque off".
Requirement
Stopping by immediately
switching off the energy
supply of the machine drive
elements
Stop where the energy of the
machine drive elements is
maintained in order to reach a
stop. The energy supply is
only interrupted, if the
standstill is attained.
Stop where the energy to the
machine drive elements is
maintained.
192-120113 N08 C3I12T11 - December 2010
System
Remark
behavior
Uncontrolled Uncontrolled stop is the stopping of a machine
stop movement by switching off the energy of the machine
drive elements.
Available brakes and/or other mechanical stopping
components are applied.
Controlled Controlled stop is the stopping of a machine movement
stop by for instance resetting the electrical command signal
to zero, as soon as the stop signal has been detected
by the controller, the electrical energy for the machine
drive elements remains however during the stopping
procedure.
Controlled This category is not covered.
stop
Compax3 device description
77