Proface APL3000B - Node Box PC - Manual (Page 118)

Chapter 5 Installation and Wiring
5-27
5.4.2 Connecting the Power Supply
This section describes the precautions for supplying a power voltage.
• If the supplied voltage exceeds the PL unit’s range, con-
nect 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 an insulating transformer.
• When supplying power to the PL 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.
• Branch Circuit Protective device shall be use for rating
20A for DC24V input device.
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
PL unit (E2).
• Select a surge absorber that has
a maximum circuit voltage greater
than that of the peak voltage of
the power supply.
PL
PL Power
PL Power
PL
PL
E2
FG
E1
Twisted-pair cord
PL
FG
T2
T1
Twisted-pair cord
PL
FG
Constant
Voltage
Transformer
I nsulating
Transformer
Input/Output
Power
Main Power
Input/Output
Unit
Input/Output
Unit
Input/Output
Unit
Operation
Unit
Main Circuit
Main
Power
Input/
Output
Power
Lightning Surge
Absorber