B&B Electronics MAP450D Control Panel Design Guidelines, Control Panel Grounding

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.

Figure 1 Control Panel Example

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 between +12 and +30 VDC. The voltage should measure between +12 and +30V at the OIT between Pins 2 and 3 of the OIT terminal block. A 24 VDC, 0.5 amp linear power supply dedicated to the OIT is recommended.

•The power leads on the operating cable for the OIT should be 18AWG 2-conductor wire with a shield wire and protective shield foil. The shield of the OIT operating cable must be connected to earth ground at both ends of the cable. Please refer to Section 2.

1010-0046A, REV 00