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XtrapulsCD1-pm
– Installation manual
Chapter 4 - Connections
Due to this voltage drop:
▪
an encoder with a large power supply voltage range should be preferred,
▪
if the encoder has got power supply SENSE feedback lines, they can be connected to the power supply lines
in order to reduce the voltage drop by the half (the SENSE feedback signal is not used in the Xtrapuls CD1
range),
▪
if none of both solutions above can be used, the user has to supply the encoder by means of an external
power supply.
Example
The application requires an Heidenhain linear encoder supplied by 5 V ±5 % / 300mA 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 = 0.21mm²
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 fan.
2.5 - SERIAL LINK CABLES
The serial link cable must also be shielded according to the above mentioned shield connection
recommendations.
2.6
– CONNECTION CABLES OF THE BRAKING RESISTOR
The connection cable to the braking resistor housing must bear the high voltage and temperature of 600 V and
105° C.
Recommended cable: UL 1015 gauge 14.
Fastening torque on the connector of the braking resistor housing: dp = 0.9 Nm.
CAUTION
Command cables (resolver, serial link, Profibus) as well as the power cables must be
connected and disconnected with the positioner OFF.
Reminder: The power voltage can remain several minutes on the capacitors terminals.
A contact under high voltage may involve severe physical damage.
!
