Hitachi SJ300 Series manual 145

4–7

SJ300 Inverter

Connecting to PLCs and Other Devices

Hitachi inverters (drives) are useful in many types of applications. During installation, the inverter keypad (or other programming device) will facilitate the initial configuration. After installation, the inverter will generally receive its control commands through the control logic terminals or serial interface from another controlling device. In a simple application such as single-conveyor speed control, a Run/Stop switch and potentiometer will give the operator all the required control. In a sophisticated application, you may have a programmable logic controller (PLC) as the system controller with several connections to the inverter.

It is not possible to cover all the possible types of application in this manual. It will be necessary for you to know the electrical characteristics of the devices you want to connect to the inverter. Then, this section and the following sections on I/O terminal functions can help you quickly and safely connect those devices to the inverter.

CAUTION: It is possible to damage the inverter or other devices if your application exceeds the maximum current or voltage characteristics of a connection point.

The connections between the inverter
and other devices rely on the electrical	Other device				SJ300 Inverter
			Signal
input/output characteristics at both ends		Input				Output
of each connection, shown in the			Return
		circuit				circuit
diagram to the right. The inverter can
accept either sourcing or sinking type		Output	Signal			Input
inputs from an external device (such as
			Return
a PLC). A terminal jumper configures		circuit				circuit
the input type, connecting the input
circuit common to the supply (+) or (–).
		PLC				Inverter
Detailed wiring examples are in “Using			Jumper
Intelligent Input Terminals” on page 4–						24VDC
11. This chapter shows the inverter’s				P24
internal electrical component(s) at each
I/O terminal and how to interface them				PLC	Common		+
							–
with external circuits.
				CM1
In order to avoid equipment damage and
get your application running smoothly,
we recommend drawing a schematic of				1
each connection between the inverter
				2
and the other device. Include the						Input
internal components of each device in
				3
the schematic, so that it makes a						circuits
complete circuit loop.
				4
After making the schematic, then:
				5
1. Verify that the current and voltage
for each connection is within the				6
operating limits of each device.
2. Make sure that the logic sense				7
(active high or active low) of any
				8
ON/OFF connection is correct.

3. Verify inputs are configured correctly (sink/source) to interface

to interface to any external devices (PLCs, etc.).

4.Check the zero and span (curve end points) for analog connections, and be sure the scale factor from input to output is correct.

5.Understand what will happen at the system level if any particular device suddenly loses power, or powers up after other devices.

Operations Monitoring and