AKD-N Installation | 6 Technical description and data
6.14.8 Local STO safety instructions
WARNING
The drive cannot hold a vertical load when STO is active. Serious injury
could result when load is not properly blocked. Drives with a suspended
load must have an additional safe mechanical blocking (for instance, by a
motor-holding brake).
The drives have not to be used for driving elevators.
CAUTION
In case of a specific double fault within a very short time (see
p. 36) a
single movement of maximum an angle of 120° (electrical) can happen.
This effect can only happen if the drive is in the function STO.
Even if the STO function will be issued for a whole year, this event will
only happen every 100 Billion years.
CAUTION
The drive might restart automatically after power on, voltage dip or inter-
ruption of the supply voltage, depending on the parameter setting.
Risk of death or serious injury for humans working in the machine.
If the parameter DRV.ENDEFAULT is set to 1, then place a warning sign
to the machine (Warning: Automatic Restart at Power On) and ensure,
that power on is not possible, while humans are in a dangerous zone of
the machine. In case of using an undervoltage protection device, you
must observe EN 60204-1:2006 chapter 7.5 .
CAUTION
The STO function does not provide an electrical separation from the
power output. There is a danger of electrical shock and personnel injury.
If access to the motor power terminals is necessary, the drive must be dis-
connected from AKD-C considering the DC Bus discharging time.
If the safety function STO is automatically activated by a control system, then make sure
that the output of the control is monitored for possible malfunction. The monitoring can be
used to prevent a faulty output from unintentionally activating the STO function. Since the
local STO function is a single-channel system, erroneous engaging will not be recognized.
It is not possible to perform a controlled brake if the drive controlled STO-Enable is off. If con-
trolled braking before the use of the STO function is necessary, the drive must be braked and
the input STO must be separated time-delayed from +24 V .
The STO Status signals are informal and not relevant for functional safety.
38
Kollmorgen | December 2014
