New computer-based control systems allow easy monitoring and remote control while new wire management systems make installation a snap.
As we all know, electronic and electromechanical technologies are coming together in an ever-increasing variety of electrical products. This melding can be seen in solid-state trip devices, programmable logic controllers, power distribution monitoring systems, and many other products. (See the March 1995 issue, "Electric West 95 Show Highlights Melding of Technologies," page 24.) A further aspect of this trend is the control of extensive distribution systems by the ubiquitous PC. Now, no matter where you are, you can use your PC (and a modem connection to a host computer) to obtain real-time data and perform necessary distribution system operations. You can even search an event log for information that will help you determine the probable cause of outages, equipment malfunctions, breaker trips, etc.
Control schemes
One manufacturer (ASCO) introduced its new Data Acquisition and Control System at the Electric 95 Show in Atlanta. The system allows operating personnel to control paralleling and distribution switchgear from a PC via a centralized computer-based interface. Using Windows[TM] software and point-and-click screens, you can operate multiple engine-generator sets, control circuit breakers, and monitor the performance of a large emergency, standby, or co-generation power system. Switchgear elevations with single line diagrams superimposed are shown onscreen. Status annunciation, remote selector switch position, analog metering, and set-point control and alarming can be viewed on separate windows. The system also can be used for event and alarm logging, historical trend analysis, and report generation.
Another manufacturer (Russelectric) introduced a microprocessor-based transfer control for its complete line of transfer and bypass/isolation switches. The integral controller senses voltage from both the normal and emergency sources and indicates the position of the switch. You interface with the panel-mounted controller via a tactile keyboard. Shown on the controller's 20-character, 4-line LCD display are various menus and sub menus as well as prompts that allow you to set adjustable parameters, set up optional accessories, control the switch, and verify operational status. An industry standard, open architecture protocol is used for high speed communications with a master programmable logic controller (PLC) or PC.
Wire managements systems
While cable tray is the predominant wire management system in Europe and Canada, accounting for up to 80% of all installations in commercial and industrial projects, conduit remains king in the U.S., with an 80% share of the market.
Represented at the Electric 95 Show was almost every cable tray manufacturer in the industry today. There were three manufacturers showing center spine trays (Mono-Systems, B-Line, and Atlas) and others featuring "traditional" tray configurations in fiberglass, steel, and aluminum constructions.
One manufacturer (Thomas & Betts) exhibited its newly acquired cable tray line and introduced an AutoCad software program for cable tray system design.
A noticed trend is the introduction of more and more unique wire management systems that increase flexibility and save installation time. One manufacturer (GS Metals) introduced a steel wire tray that can be field-modified for any physical obstructions encountered such as columns, pilasters, pipes, etc. By cutting the tray's bottom or side wires with an offset head bolt cutter and hand bending the tray, you can make vertical or horizontal bends and/or offsets as required. Bolt-rod supported hangers clip onto the tray's side wires. Wire or cable is laid in, not pulled in, by lifting the tray off individual hangers one at a time. The product is available in four finishes: electro galvanized after fabrication; hot-dipped galvanized after fabrication, 316L stainless steel; and equipment gray powder coat.
Another trend is the ever-increasing number of manufacturers entering the surface raceway market. One manufacturer (Dekko Engineering) primarily involved in the office furniture industry introduced at the show a new pre-wired, thin profile, combination high and low tension surface raceway line. Power wiring consists of two No. 12 AWG phase wires, two No. 12 AWG neutral wires, and one No. 12 AWG ground wire. Data, telephone, and/or coaxial cables are installed in an integral channel with a snap-in cap.
Carbon Monoxide Detectors
At least four manufacturers of carbon monoxide detectors exhibited their products at the show. In discussions with these manufacturers, we learned that they are hoping for the grass-roots movement requiring these devices in all new residences (now at the state level only) will spread nationally. Despite negative publicity last year about reports of detector false alarms in the Chicago area, this is a potentially lucrative market for the electrical industry.