3.1 Main Circuit Wiring3-93 Wiring and Connection3.1.4 General Precautions for WiringTo ensure safe, stable application of the servo system, observe the following precautions when wiring.Use the connecting cables specified in theΣ-V Series Product Catalog (KAEP S800000 42). Designand arrange the system so that each cable will be as short as possible.Observe the following precautions when wiring the main circuit.• Use shielded twisted-pair wires or shielded multi-core twisted-pair wires for signal lines and encoder linesfor serial converter unit.• The maximum wiring length is 3 m for signal lines and 50 m for encoder lines for serial converter unit.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 100Ω or less 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 or 0.3 mm. Do not impose excessive bendingforce 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 isolatedthrough 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 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 highcharging current to flow when power is turned ON. Frequently turning power ON andOFF will causes the main circuit elements in the SERVOPACK to deteriorate.