Control Cable Grounding - ABB MicroFlex e190 User Manual

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Control cable grounding

The shields of all control cables must be grounded at the earth bar. Use M4 screws to
fasten cable clamps.
The shields should be continuous as close to the terminals as possible. Only remove
the outer jacket of the cable at the cable clamp so that the clamp presses on the bare
shield. At the terminal block, use shrink tubing or insulating tape to contain any stray
strands. The shield (especially in case of multiple shields) can also be terminated
with a lug and fastened with a screw at the earth bar. Leave the other end of the
shield unconnected or ground it indirectly via a few nanofarads high-frequency
capacitor (e.g. 3.3 nF / 630 V). The shield can also be grounded directly at both ends
if they are in the same ground line with no significant voltage drop between the end
points.
Keep any signal wire pairs twisted as close to the terminals as possible. Twisting the
wire with its return wire reduces disturbances caused by inductive coupling.
Electrical installation: input / output 73
Use shrink tubing or tape to contain strands
Remove outer jacket of cable at clamp to
expose cable shield
Earth bar
M4, 10 mm, 1.0...1.3 N·m (8.9...11.5 lbf·in)