Grounding Of Protective Shields; Operation Principle; Start-Up Including Acceptance Test; Authorized Person - ABB ACS560 Hardware Manual

a wiring method (shield grounding, channel separation) which reduces or eliminates the risk
caused by the short-circuit.
Note:
The voltage at the INx terminals of each drive must be at least 13 V DC to be interpreted
as "1". Pulse tolerance of input channels is 1 ms.
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Grounding of protective shields

• Ground the shield in the cabling between the activation switch and the control board at
the control board.
• Ground the shield in the cabling between two control boards at one control board only.

Operation principle

1. The Safe torque off activates (the activation switch is opened, or safety relay contacts
open).
2. The STO inputs IN1 and IN2 on the drive control board de-energize.
3. The STO cuts off the control voltage from the drive IGBTs.
4. The control program generates an indication as defined by parameter.
The parameter selects which indications are given when one or both Safe torque off
(STO) signals are switched off or lost. The indications also depend on whether the drive
is running or stopped when this occurs.
Note:
This parameter does not affect the operation of the STO function itself. The STO function
will operate regardless of the setting of this parameter: a running drive will stop upon
removal of one or both STO signals, and will not start until both STO signals are restored
and all faults reset.
Note:
The loss of only one STO signal always generates a fault as it is interpreted as a
malfunction of STO hardware or wiring.
5. Motor coasts to a stop (if running). The drive 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.
￭

Authorized person

The acceptance test of the safety function must be carried out by an authorized person with
expertise and knowledge of the safety function. The test must be documented and signed
by the authorized person.
Safe torque off function 153