DOC-0017-03-EN: AC15 Series - Hardware Installation Manual
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DOC-0017-03-EN-B 04.04.2023
Comprehensive Checks
A comprehensive check of the STO function ensures the overall integrity of the STO functionality. It proves
the independent operation of each channel individually (including during the normal dual channel
operation), and the essential single fault detection.
It must always be performed:
- During factory test.
- During commissioning activities.
- After repair or replacement of the inverter.
- After any hardware or software design changes which may affect the inverter concerned.
- After each intervention into the system and control wiring.
- A minimum of once per year.
- If the machine has been idle for more than a period of time determined by the machinery builder
and user risk assessments.
The check must be made by suitably qualified professional personnel following all necessary safety
precautions. They must be fully conversant with all equipment concerned.
Note: In the following text where it is required that “all power” is removed, remove power and wait
10 minutes.
The performance of the individual test steps of the STO function should be logged.
WARNING!
Potential loss of Safety Function:
During this test, the safety function must not be relied on because at times
only one channel will be activated and therefore the intended safety
function may not be available.
STO will be activated while the motor is rotating, which is not the normal
operation. Therefore, the user must ensure it is safe to do this test using
an appropriate risk assessment and taking any additional risk reduction
measures.
The following steps must be performed and recorded during a comprehensive check:
STO Test
Step
Test Check or Activity
Expected Reaction & Effect
Initial Check (Basic Inverter Functionality)
1
Firstly, ensure that no harm can come to
personnel or equipment if the motor turns.
None.
2
Apply +24Vdc to the inverter control board
terminals STOA and STOB, and 0V to the
STO 0V terminal.
None.
3
Switch on power to the inverter.
No error must be present in the drive
system.
4
Configure the inverter and associated
equipment if necessary, so that it can be
started and stopped, and responds to a
speed setpoint provided.
No error must be present in the drive
system.
5
Try to start the inverter with a non-zero
setpoint. This setpoint value will be referred
to as SPT1 for brevity in these tests. Leave
this set throughout all tests.
Inverter must start and the motor must turn
at SPT1.
