User's Manual

21
3.3 Wiring
A careful wiring is absolutely necessary to guarantee a troublefree operation of the servo
amplifier!
The control line for the servo amplifier, the signal lines of the motor and the motor lines are
to be wired separately.
See also ÑMeasures for an installation in conformity to the EMC directive.
3.3.1 Protective Earth Terminal
Power GND (ST1 26z,b,d) must be connected with the protective earth terminal. Control
unit and amplifier must have an equal potential. The equalized potential must be realized by
a single connection between control unit and amplifier (ST1 26z,b,d). This connection
should be a sufficiently strong line. The conductor cross section should at least correspond
to that of the motor line, however, should not be smaller than 1.5mm
2
. As in the amplifier
Power GND (ST1 26z,b,d), GND (ST1 18z and ST1 16z) and GND-REF (ST1 4z) are
connected, no further terminal must be connected with control GND, to avoid ground loops.
3.3.2 Resolver Cable
The resolver cable must be shielded. The pairs S1/S3, S2/S4 and R1/R2 must be twisted.
The shorter the twist, the better it is. Each pair has to be shielded separately within the total
shield (see 3.5). The internal shields are to be connected to connector ST2 with ST2.6,
ST2.7, ST2.8, the external shield is to be connected to the connector housing. Connection
of the shields on the side of the motor is not allowed, and not to the connector housing
either, as otherwise interference currents of the motor winding may be discharged through
this shield, which would partly wreck the shielding effect (ground loops).
3.3.3 The Line Cable of the Motor
The power supply of the motor, that means the actual motor cable, has to consist of four
stranded cores (U
1
,V
1
,W
1
,PE). The shorter the twist, the better it is. In order to minimize
interference emission, you have to use a shielded cable. The shield must be connected
with a low inductance to POWER GND (26z,b,d). On the motor side the shield has to be
connected to the motor housing via the metallic connector housing. To guarantee a reliable
functioning of the protective function ground contact resistance (safety against contact of
the winding with the housing), the motor housing has to be connected with POWER GND
(26z,b,d).