67
DC Power Source
Supply 24 VDC. Keep voltage fluctuations within the specified range (19.2 to
28.8 V).
Power Consumption
The power consumption will be 40 W max. per Rack, and there will be a surge
current of at least 5 times the max. power when power is turned on.
Crimp Terminals
The terminals on the Power Supply Unit are M3.5, self-raising terminals with
screws.
Use crimp terminals for wiring. Do not connect bare stranded wires
directly to terminals. Tighten the terminal block screws to the torque of 0.8 N
S
m.
Use crimp terminals (M3.5) having the dimensions shown below.
7 mm max.
7 mm max.
Do not reverse the positive and negative poles when wiring the power supply
terminals.
Supply power to all of the Power Supply Units from the same source.
Do not forget to remove the label from the top of the Power Supply Unit before
turning on the power supply to ensure proper heat dissipation.
For satisfying the EC Directives (Low-voltage Directives), provide reinforced
insulation or double insulation for the DC power supply used for the CPU Unit.
Grounding
Power Supply Unit
L
2
/N
L
1
To avoid electrical shock, attach a grounded (earth ground) AWG 14 wire (cross-
sectional area of at least 2 mm
2
) to the GR terminal. The resistance to ground
must be 100
Ω
or less. Do not use a wire longer than 20 m. Care must be taken,
because ground resistance is affected by environmental conditions such as soil
composition, water content, time of year, and the length of time since the wire
was laid underground.
The Line Ground (LG) terminal is a noise-filtered neutral terminal that does not
normally require grounding. If electrical noise is a problem, however, this termi-
nal should be connected to the Ground (GR) terminal.
PC operation may be adversely affected if the ground wire is shared with other
equipment, or if the ground wire is attached to the metal structure of a building.
Wiring
Section 3-2
