Proface AGP3500 - 10.4 DIO HMI" - Manual (Page 91)

ST3000 Series Hardware Manual
4-12
4.2.2 Connecting the Power Supply
This section describes the precautions for supplying a power voltage.
• If the supplied voltage exceeds the ST unit’s range,
connect a constant voltage transformer.
• Between the line and ground, select a power supply that
is low in noise. If there is an excess amount of noise,
connect a insulating transformer.
• When supplying power to the ST unit, be sure to
separate the input/output and power lines, as shown.
• To increase the noise resistance quality of the power
cord, simply twist each power wire before attaching the
Ring Terminal.
• The power supply cable must not be bundled or
positioned close to main circuit lines (high voltage, high
current), or input/output signal lines.
• Connect a lightning surge absorber, as shown in the
diagram, to deal with power surges.
• To avoid excess noise, make the power cord as short as
possible.
• DC24V input unit is must be used with a Class 2 power
supply.
SEE Chapter 3 Specifications (page 3-1)
• Use constant voltage and
insulating transformers with
capacities exceeding Power
Consumption value.
• Be sure to ground the surge
absorber (E1) separately from the
ST unit (E2).
• Select a surge absorber that has
a maximum circuit voltage greater
than that of the peak voltage of
the power supply.
ST
ST Power
Input/Output
Power
Main Power
ST
Main Circuit
Lightning Surge
Absorber
ST
E2
FG
E1
Constant
Voltage
Transformer
Twisted-pair cord
ST
FG
Insulating
Transformer
T2
T1
Twisted-pair cord
ST
FG
Input/Output
Unit
Main
Power
ST
Power
Input/
Output
Power
Input/Output
Unit
Input/Output
Unit
Operation
Unit