Installing the PLC2/DHII Interface
Chapter 4
417
ON
AC POWER
OFF
FUSE
SLOW BLOW
2A, 250V
115V AC/230V AC
INTERNALLY
SWITCH
SELECTABLE
L1
L2/N
GND
Connect L1 to high side
of transformer.
Connect L2/N to low side
of transformer.
Connect GND post to
central ground bus.
Connect a separate transformer between the AC power source and the
interface power supply to provide DC isolation from other equipment.
Connect the transformer primary to the AC source; connect the high side
of the transformer secondary to the L1 terminal of the power supply;
connect the low side of the transformer secondary to the L2/N terminal of
the power supply.
The power consumed by the PLC-2/DHII interface is 50W. Multiply the
power requirements of the Allen-Bradley power supplies by 3, and add all
other power requirements (input circuits, output circuits) to determine the
required rating of the transformer. The power requirements must take into
consideration the surge currents of devices controlled by the controller.
The minimum transformer rating requirement for the PLC-2/DHII
interface is 125V AC.
DHII power supplies that are set up for 115V AC operation are designed
to generate a shutdown whenever the AC line voltage drops below
85 volts and to allow the interface to resume operation when the line
voltage reaches 85 volts again. For power supplies that are set up for
230V AC operation, the shutdown level is 170V AC.
Power Distribution
