4 residual hazards, Safety instructions – Lenze 931W User Manual
Page 12

Safety instructions
Residual hazards
2
12
HB 13.0001-EN 3.0
2.4
Residual hazards
Protection of persons
After power-off, the pins of the connection X2 (+320 V DC, 230 V AC L1, N or 0 V DC), UL, BR
and GND still carry hazardous voltages for at least 3 minutes!
ƒ
Before working on the controller, check that no voltage is applied to the power
terminals.
ƒ
Always protect the power terminals against contact.
The discharge current to ground (PE) is > 3.5 mA, in accordance with EN 50178
ƒ
If a fixed installation is required, just design the PE conductor with a cable
cross-section of at least 1.5 mm
2
, or design the PE conductor double.
Observe appropriately installed cables, correct bolted connections, and correct plug
connections.
Due to the high currents in applications with extra-low voltages, current-carrying parts
can be strongly heated.
Device protection
ƒ
Connect or disconnect all pluggable terminals in a deenergised state only!
ƒ
A cyclic connection and disconnection of the supply voltage can overload and
destroy the input current limitation of the drive controller:
– When effecting a cyclic switching of the supply voltage over a longer period, the
period between two switch-on processes at least has to be one minute!
Motor protection
Drive systems can reach dangerous overspeeds (e.g. setting of high field frequencies for
motors and machines which are not qualified for this purpose):
ƒ
The controllers do not offer any protection against these operating conditions. Use
additional components for this.
Protection of the machine/system
A missing or incorrect resolver adjustment can bring about undefined control states. The
perfect operation is no longer guaranteed.