Operation Principle; Start-Up Including Acceptance Test; Competence; Acceptance Test Reports - ABB ACS880-37 Hardware Manual

Operation principle

1. The Safe torque off activates (the activation switch is opened, or safety relay contacts
open).
2. The STO inputs on the inverter control unit de-energize.
3. The control unit cuts off the control voltage from the inverter IGBTs.
4. The control program generates an indication as defined by parameter 31.22 (refer to
the firmware manual of the inverter).
5. Motor coasts to a stop (if running). The inverter cannot restart while the activation
switch or safety relay contacts are open. After the contacts close, a new start
command is required to start the drive.

Start-up including acceptance test

To ensure the safe operation of a safety function, validation is required. The final
assembler of the machine must validate the function by performing an acceptance test.
The acceptance test must be performed
•
at initial start-up of the safety function
•
after any changes related to the safety function (circuit boards, wiring, components,
settings, etc.)
•
after any maintenance work related to the safety function.

Competence


The acceptance test of the safety function must be carried out by a competent person with
adequate expertise and knowledge of the safety function as well as functional safety, as
required by IEC 61508-1 clause 6. The test procedures and report must be documented
and signed by this person.

Acceptance test reports


Signed acceptance test reports must be stored in the logbook of the machine. The report
shall include documentation of start-up activities and test results, references to failure
reports and resolution of failures. Any new acceptance tests performed due to changes or
maintenance shall be logged into the logbook.
The Safe torque off function 243