3 Wiring and Connection
3.1.4 General Precautions for Wiring
3-18
3.1.4
General Precautions for Wiring
To ensure safe, stable application of the servo system, observe the following precautions when wiring.
• Use the specified connection cables. Use the connection cables specified in the
Large-Capacity
Σ
-V Series
Product Catalog
(No.: KAEP S800000 86). Design and arrange the system so that each cable will be as
short as possible.
• Use shielded twisted-pair cables or screened unshielded twisted-pair cables for I/O signal cables and
encoder cables.
• Use the busbars that are included with the converter and connect the P and N terminals on the SERVOPACK
and converter securely.
• The maximum cable length is 3 m for I/O signal cables, 50 m for connection cables for servomotor main cir-
cuit or encoder cables, and 10 m for control power supply cables to 400-V converters (+24 V, 0 V).
• Observe the following precautions when wiring the ground.
• Use a cable as thick as possible (at least 2.0 mm
2
).
• Grounding to a resistance of 100
Ω
or less for 200-V SERVOPACKs, 10
Ω
or less for 400-V SERVO-
PACKs or converters is recommended.
• Be sure to ground at only one point.
• Ground the servomotor directly if the servomotor is insulated from the machine.
• The signal cable conductors are as thin as 0.2 mm
2
or 0.3 mm
2
. Do not impose excessive bending force or
tension.
• Use a molded-case circuit breaker (1QF) or fuse to protect the main circuit.
The SERVOPACKs and converters connect directly to a commercial power supply;
They are not isolated through a transformer or other device.
Always use a molded-case circuit breaker (1QF) or fuse to protect the servo system
from accidents involving different power system voltages or other accidents.
• Install a ground fault detector.
The SERVOPACKs and converters do not have a built-in protective circuit for ground-
ing.
To configure a safer system, install a ground fault detector against overloads and
short-circuiting, or install a ground fault detector combined with a molded-case circuit
breaker.
• Do not turn the power ON and OFF more than necessary.
• Do not use a SERVOPACK or converter for applications that require the power to
turn ON and OFF frequently. Such applications will cause elements in the SERVO-
PACK or converter to deteriorate.
• As a guideline, at least one hour should be allowed between the power being
turned ON and OFF once actual operation has been started.
