Yaskawa Sigma-5 User Manual: Design and Maintenance - Rotary Motors - MECHATROLINK-II Communications Reference - Manual (Page 66)

3.1 Main Circuit Wiring
3-17
3
Wi
ring and
C
onne
ctio
n
3.1.6 General Precautions for Wiring
To ensure safe, stable application of the servo system, observe the following precautions when wiring.
• Use the connection cables specified in the Σ -V Series Product Catalog (No.: KAEP S800000 42). 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.
• The maximum wiring length is 3 m for I/O signal cables, 50 m for encoder cables or servomotor main cir-
cuit cables, and 10 m for control power supply cables for the SERVOPACK with a 400-V power supply
(+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 100-V, 200-V SERVOPACKs, 10 Ω or less for 400-V SER-
VOPACKs 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 SERVOPACK connects directly to a commercial power supply; it is 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 SERVOPACK does not have a built-in protective circuit for grounding.
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 the SERVOPACK for applications that require the power to turn ON and
OFF frequently. Such applications will cause elements in the SERVOPACK to dete-
riorate.
• As a guideline, at least one hour should be allowed between the power being
turned ON and OFF once actual operation has been started.