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Chapter 4
– Connections
XtrapulsCD1-a
Example
The application requires an Heidenhain linear encoder supplied by 5 V ±5 % / 300 mA with 25 m cable length.
Min. power voltage: 5 V ±5 %
U
max
= 0.25 V
. Min. cross section: S = 1.2 mm².
Such a large cross section is difficult to obtain, so the user can:
either connect the SENSE feedback signal lines with power supply lines, while the needed wires cross section
will be the half (0.6 mm²),
or use the same encoder type but the version which allows its power supply voltage from 3.6 V to 5.25V /
300mA. Min power voltage 3.6V
U
max
= 1.4V
. Min. cross section : S = 0.21 mm²
The cables of brake equipped motors must also have their brake cables shielded in order to be EMC compliant.
Maximum cable length: - resolver:
100 m
- encoder:
25 m
-
motor:
≤ 25 m
For motor cable length > 25 m, we advise:
- to use the maximum cable section allowed by the connectors,
- to mount a reactance with an inductive value between 1 % and 3 % of the motor inductive value. The reactance
inductive value must be taken into account in the calculation of the current loops. The current rating of the
reactance must be equal to or higher than the drive rating. The reactance must be mounted at the drive output.
Due to the use of a reactance, a shielded cable is not mandatory anymore. A more complex sinus filter type
B84143V x R127 by Epcos may also be mounted instead of the reactance.
UNDESIRABLE EFFECTS OF MOTOR CABLES LONGER THAN 25 m:
- Heating of the power module, the motor and the cable.
- High overvoltage on the motor windings involving a shortening of their life time.
The reactance reduces the undesirable effects on motor and drive but it may be quite heated. This requires an
appropriate cooling.
2.5 - INPUT COMMAND AND SERIAL LINK CABLES
The analog input command signal CV requires a pair twisted and shielded cable. The shield must have a "360°"
connection via metallic connectors at both cable ends.
The input command (CV) wiring must be made according to the polarity between the controller and the drive (CV+
on "diff high" of the controller). The logic 0 Volt is directly connected to the drive housing. The ground connection
continuity is ensured by the fastening screws of the front panel sub-D connectors.
But the drive 0 V and the
controller 0 V MUST be connected together by means of a wire. The shield MUST NEVER be used as a
conductor of the 0 Volt potential
.
The serial link cable must also be shielded according to the above mentioned shielding recommendations.
2.6 - CONNECTION CABLES OF THE BRAKING RESISTOR
The connection cable to the braking resistor housing must be able to bear high voltage and temperature such as
600 V and 105° C.
Recommended cable = UL 1015 Gauge 14.
Fastening torque on the housing connector: dp = 0.9 Nm.
CAUTION!
The command cables (input command, serial link, position, resolver, encoder) as well as the power
cables MUST be connected and disconnected with the drive TURNED OFF.
Reminder: The power voltage may remain several minutes on the capacitors terminals.
A contact under high voltage may involve severe physical damage.
