Mitsubishi Electric FR-V5AX, Instruction Manual

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9
HIGH RESOLUTION ANALOG INPUT
3.5 Noise reduction techniques
Use the following techniques if an analog signal is compounded with noise, resulting in instable operation.
(1) Techniques for wiring
1) Separate the power and signal cables as far as possible.
2) Use a twisted pair shield cable as the signal cable.
Handle the shield cable in any of the following ways.
•
Connect it to the No. 5 terminal of the FR-V5AX.
•
Connect it to the common terminal on the analog command device side.
•
Connect it to both the No. 5 terminal of the FR-V5AX and the common terminal on the analog com-
mand device side.
•
Connect it to neither the No. 5 terminal of the FR-V5AX nor the common terminal on the analog
command device side. (Keep the shield cable suspended.)
(2) Techniques on the inverter side
Decrease the setting of Pr. 72 "PWM frequency selection". (Motor-produced sound increases but in-
verter-generated noise reduces.)
Increase the settings of the speed (torque) setting filters, Pr. 822, Pr. 832 (Pr. 826, Pr. 836).
(3) Others
Install the FR-BLF line noise filter (FR-BSF01 for 3.7K or less).
Reinforce or separate earthing.
3.6 Specifications
Resolution 0.003% at 0 to 10V input (16 bits)
Input resistance 14k
Ω
Max. input voltage 20V
CAUTION
Changing the speed (torque) setting filter value affects the response level of the inverter to a com-
mand. Therefore, adjust it while simultaneously looking at the machine motion.