1. Control Panel Design Guidelines
Pay careful attention to the placement of system components and associated cable
routing. These items can significantly enhance the performance and integrity of
your control application.
1.1. Control Panel Grounding
• The control panel should be connected to a good, high-integrity earth ground
both for safety considerations and shielding purposes. This must be a reliable
earth ground with a low-resistance path. The ideal earth ground would be a
copper grounding rod located close to the OIT and the control panel.
• Hinged doors on control panels do not provide a long term electrical connection
to the rest of the enclosure. Corrosion develops over time and prevents good
electrical contact. For this reason, a separate wire braid should be installed from
the hinged control panel to the rest of the enclosure.
1.2. Power Supply Selection
• The power supply used to power the OIT should have an output b12
and +30 VDC. The voltage should measure b12 and +30V at the OIT
between Pins 1 and 2 of the power connector. A 24 VDC, 0.5 amp linear power
supply dedicated to the OIT is recommended.
• The power cable for the OIT should be 18AWG 2-conductor wire with a shield
wire and protective shield foil. The shield of the OIT power cable must be
connected to earth ground at both ends of the cable. Please refer to the “Connect
OIT to Power” section and Appendix C for more information.
6
OIT3200/3250
1010-0081A, REV 04
I / O CONTROL LINES
OIT OPERATING
CABLE
PLC/HOST
GROUND WIRES
OIT REAR
GROUND
POWER LINE
QUIET GROUND(ISOLATED)
OIT GROUND
QUIET
FILTER
LINE
SUPPLY
POWER
OIT
OIT
SHIELDED POWER CABLE
SHIELDED
COMMUNICATION
CONTROL PANEL
TIED TO RELIABLE
EARTH GROUND
FILTER
CABLE
COVER
STRAP
GROUND
Figure 1 Control Panel Example
