Siemens SIRIUS 3RW30 Manual page 47

Automatic restart
Can result in death, serious injury, or property damage.
The automatic RESET mode (AUTO RESET) must not be used in applications where there is
a risk of serious injury to persons or substantial damage to property if the motor starts up
again unexpectedly. The start command (e.g. issued by a contact or the PLC) must be reset
prior to issuing a RESET command because the motor attempts to restart again
automatically following this RESET command if a start command is still present. This
particularly applies if the motor protection has tripped. For safety reasons, you are advised to
integrate the group fault output on the 3RW40 (terminals 95 and 96), or the signaling contact
of the motor or miniature circuit breaker on all devices, in the controller.
Notes on troubleshooting
Warning
Impermissible I CLASS setting
e
(control voltage present, no start
command)
Start inhibited, device too hot
SIRIUS 3RW30 / 3RW40
Manual, 01/2010, 535 1995-02 DS01
WARNING
Cause
The rated operational current I
the motor (control voltage present, no
start command) exceeds the associated,
maximum permissible setting current
referred to the selected CLASS setting
(chapter Motor current settings [Page
107]).
The acknowledgment and the motor start
are inhibited for a defined time by the
inherent device protection following an
overload trip, to allow the 3RW40 to cool
down.
Possible causes
• Too many starts,
• Motor ramp-up time too long,
• Ambient temperature in switching
device's environment too high,
• Minimum installation clearances not
complied with.
5.7 Diagnostics and fault signals
Remedy
set for Check the rated operational current set
e
for the motor, select a lower CLASS
setting, or calculate the soft starter with a
size allowance.
As long as the 3RW40 is not controlled
IN (0->1), this is only a status signal.
However, it becomes a fault signal if the
start command is applied.
The device cannot be started until the
temperature of the thyristor or the heat
sink has cooled down enough to
guarantee sufficient reserve for a
successful startup. The time until
restarting is allowed can vary but is a
minimum of 30 s.
Rectify the causes and possibly retrofit
the optional fan (3RW40 2. to 3RW40 4.).
Functions
47