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Termination resistor, Wiring of a control terminal – Toshiba TOSVERT VF-FS1 Series User Manual

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E6581371c

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3.5. Termination resistor

Terminate the network bus with about 52.3ohm impedance to minimize the reflections. There are
two choices for the termination.
1. Free Topology Network Segment

Only one termination and may be placed anywhere on the free topology segment.
RC network (Following figure), with R1 = 52.3ohm +/-1%, 1/8W

2. Doubly Terminated Bus Topology Segment.

It is necessary to terminate at both ends of a twisted pair bus.
RC network (Following figure), with R1 = 105ohm +/-1%, 1/8W

C1 and C2 are required for connection to link power network.

C1, C2: Aluminum-electrolytic type

100uF, 50V min

C1

R1

C2

Terminal circuit

3.6. Wiring of a control terminal

Observe the following when wiring.

- Use 0.3 to 1.5mm

2

solid/stranded wire (AWG 22 to 16) for control cables.

- Remove the sheath of a cable about 7mm (6mm for FLA, FLB, FLC and G/E) from the end of cable.
- Use a flat-headed screwdriver with its blade 0.6mm in thickness and 3.5mm in width.
- Screw tightening torque for the terminal block screws should be 0.5 to 0.6Nm.

N.B.: Keep the control signal cables 20cm or more separate from the power cables to prevent from

malfunctioning due to electromagnetic noise.

N.B.: Provide an inter-lock system stated in below, when using a programmable controller that has

the open collector output.
When the programmable controller is turned off with the inverter is on, the difference
between each control power potential will cause wrong signals to the inverter as shown in
below figure. Provide an inter-lock so that the programmable controller cannot be turned off
when the inverter power is alive.

COM

+24V

Inverter

internal +24V

External

+24V supply

VF-FS1 + LIU007Z

Programmable controller

Input terminal

Fuse blowout
detection
circuit

Fuse