Other Precautions - YASKAWA E-V-MD Series User Manual

4 Installation

4.1.6 Other Precautions

4.1.6

Other Precautions

(1) Cable Stress
Do not bend or apply tension to the servomotor/encoder relay cable.
Be especially careful to wire encoder cables so that they are not subject to stress because the core wires are
very thin at only 0.2 or 0.3 mm
 Handling Precautions for Standard Cables
The standard servomotor/encoder relay cables cannot be used in cases where high flexibility is needed, such as
when the cables themselves move or are twisted or turned. R15 min. is recommended for the bending radius of
standard cables. Use flexible cables for flexible applications.
 Handling Precautions for Flexible Cables
• Life of Flexible Cable
The flexible cable supports
= 90 mm under the following test conditions.
• Repeat moving one end of the cable forward and backward for 320 mm using the test equipment shown in the fol-
lowing figure.
• Connect the lead wires in parallel, and count the number of cable return motion times until a lead wire is discon-
nected. Note that one reciprocation is counted as one test.
Note 1. The life of flexible cable differs largely depending on the amount of mechanical shocks, mounting to the cable,
2. The life of flexible cable indicates the number of bending times in which lead wires are electrically conducted
• Wiring Precautions
Even if the recommended bending radius R is followed in the mechanical design, incorrect wiring may cause the
early disconnection. Observe the following precautions when wiring.
• Cable twisting
Straighten the flexible cables wiring.
Twisted cables cause the early disconnection. Check the indication on the cable surface to make sure that the
cable is not twisted.
• Fixing method
Do not fix the moving points of the flexible cable, or stress on the fixed points may cause early disconnection.
Fix the cable at the minimum number of points. Do not put stress on the servomotor-end and SERVOPACK-
end connectors.
• Cable length
If the cable length is too long, it may result the cable sagging. If the cable length is too short, excessive tension
on the fixed points will cause the early disconnection. Use a flexible cable with the optimum length.
4-4
2
.
10 , 000 , 000 or more operations of bending life with the recommended bending radius R
and fixing methods.
and by which no cracks and damages that affects the performance of cable sheathing are caused. Disconnecting
the shield wire is not taken into account.
Shifting Distance 320 mm
Bending
Radius
R=90 mm
Shifting End
Fixed End