Yaskawa Sigma-5 User Manual: Design and Maintenance - Rotary Motors - Manual (Page 62)

3 Wiring and Connection
3.1.6 General Precautions for Wiring
3-18
3.1.6 General Precautions for Wiring
To ensure safe, stable application of the servo system, observe the following precautions when wiring.
Use the connecting cables specified in the Σ -V Series Product Catalog (KAEP S800000 42). Design
and arrange the system so that each cable will be as short as possible.
• Use shielded twisted-pair wires or shielded multi-core twisted-pair wires for signal cables and encoder
cables.
• The maximum wiring length is 3 m for signal cables, 50 m for encoder cables and servomotor main circuit
cables, and 10 m for control power supply cables for SERVOPACKs with a power supply of 400 V(+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 SERVOPACKs with a power supply of 100 V or 200 V and
10 Ω or less for SERVOPACKs with a power supply of 400 V 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 config-
ure a safer system, install a ground fault detector against overloads and short-circuit-
ing, or install a ground fault detector combined with a molded-case circuit breaker.
Do not turn power ON and OFF frequently.
• The power supply in the SERVOPACK contains a capacitor, which causes a high
charging current to flow when power is turned ON. Frequently turning power ON and
OFF will causes the main circuit elements in the SERVOPACK to deteriorate.