Читать книгу Automation of Water Resource Recovery Facilities - Water Environment Federation - Страница 66

The following items should be considered when specifying panel-mounted devices:

• Pilot lights, including colors and types (light-emitting diode, incandescent, neon, push-to-test functions, physical size, NEMA rating, voltages, etc.);

• Pushbuttons (sizes, colors, NEMA rating, voltage rating, maintained or momentary contacts, and operator type);

• Selector switches and potentiometers (sizes, NEMA rating, voltages, maintained or momentary contacts, and maximum resistance value for potentiometer);

• Strobes (lens colors, NEMA rating, voltages, and mounting);

• Horns (decibel rating, voltages, and NEMA rating);

• Terminals (fused, nonfused types, density, voltage rating, etc.);

• Surge protection devices (types per Underwriters Laboratories [2009] UL 1449, 3rd edition); and

• Panel wiring (wire markers and wire terminations) such as

Relays (control, isolation, time delay, industrial type, voltages, and contact rating);

Timers (elapsed time, electromechanical, electronic battery backed, and other types);

Wireways;

Panel markings and labeling;

Power supplies (redundancy requirements, voltage I/O, regulation, etc.);

Power conditioners;

Breakers, fuses, and disconnect switches;

Process display meters;

Single-loop controllers (see Chapter 14 for more details);

Wireless devices; and

Signal conditioners.