User guide

26 Unidrive SP Short Form Guide
www.controltechniques.com Issue Number: 2
4 Electrical Installation
Electric shock risk
The voltages present in the following locations can cause severe electric shock and
may be lethal:
• AC supply cables and connections
• DC and brake cables, and connections
• Output cables and connections
• Many internal parts of the drive, and external option units
Unless otherwise indicated, control terminals are single insulated and must not be touched.
WARNING
Isolation device
The AC supply must be disconnected from the drive using an approved isolation device
before any cover is removed from the drive or before any servicing work is performed.
WARNING
STOP function
The STOP function does not remove dangerous voltages from the drive, the motor or any
external option units.
WARNING
SAFE TORQUE OFF function
The SAFE TORQUE OFF function does not remove dangerous voltages from the drive,
the motor or any external option units.
WARNING
Stored charge
The drive contains capacitors that remain charged to a potentially lethal voltage after the
AC supply has been disconnected. If the drive has been energized, the AC supply must
be isolated at least ten minutes before work may continue.
Normally, the capacitors are discharged by an internal resistor. Under certain, unusual fault
conditions, it is possible that the capacitors may fail to discharge, or be prevented from being
discharged by a voltage applied to the output terminals. If the drive has failed in a manner
that causes the display to go blank immediately, it is possible the capacitors will not be
discharged. In this case, consult Control Techniques or their authorized distributor.
WARNING
Equipment supplied by plug and socket
Special attention must be given if the drive is installed in equipment which is connected
to the AC supply by a plug and socket. The AC supply terminals of the drive are
connected to the internal capacitors through rectifier diodes which are not intended to
give safety isolation. If the plug terminals can be touched when the plug is disconnected
from the socket, a means of automatically isolating the plug from the drive must be used
(e.g. a latching relay).
WARNING
Permanent magnet motors
Permanent magnet motors generate electrical power if they are rotated, even when the
supply to the drive is disconnected. If that happens then the drive will become energized
through its motor terminals.
If the motor load is capable of rotating the motor when the supply is disconnected, then
the motor must be isolated from the drive before gaining access to any live parts.
WARNING