3 Wiring and Connection3.1.4 General Precautions for Wiring3-183.1.4 General Precautions for WiringTo 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-CapacityΣ-V SeriesProduct Catalog (No.: KAEP S800000 86). Design and arrange the system so that each cable will be asshort as possible.• Use shielded twisted-pair cables or screened unshielded twisted-pair cables for I/O signal cables andencoder cables.• Use the busbars that are included with the converter and connect the P and N terminals on the SERVOPACKand 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 mm2. Do not impose excessive bending force ortension.• 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 systemfrom 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 andshort-circuiting, or install a ground fault detector combined with a molded-case circuitbreaker.• Do not turn the power ON and OFF more than necessary.• Do not use a SERVOPACK or converter for applications that require the power toturn 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 beingturned ON and OFF once actual operation has been started.
