New tagging relays are it for circuit breakers - Instrumentation & Controls

Diesel Progress North American Edition, May, 2003 by Mark McNeely

Switches are ubiquitous in the power generation industry. Whether mobile or stationary, any power generation system from kilowatts to megawatts has any number of switches and relays for power control functions. That these switches and relays need to be durable and reliable is self-evident, given the often critical nature of commercial and military applications.

Electroswitch, headquartered in Weymouth, Mass., is an industry leader in the design and manufacture of tough, reliable switches, relays and other electrical system products for utility industrial and military environments. From its founding in 1946, Electroswitch has grown into the Electro Switch Corp., employing over 300 people at five locations in Massachusetts and North Carolina. Over that time, Electroswitch became a major switch provider to the military as well as both the heavy-duty industrial and electric power markets, according to Bill Conklin, national sales manager for the company.

"All of this dedication to quality; customer service and on-time delivery has earned Electroswitch products a place at virtually every North American power utility on every U.S. Navy ship, and in many of the most critical Industrial switch applications worldwide," Conklin said.

The company recently announced the availability of the Series 24 and 31 tagging relays for remote or manual circuit breaker operation. Designed for new or existing automated power distribution systems, the relays are available with two or three positions and feature orange hot-line tags to help ensure safety Two position models offer normal and tagged positions, while three position models have closed, open and tagged positions. All models allow bidirectional operation and have two N/C and two N/C contact per deck. Standard operating voltages are 48 Vd.c. and 125 Vd.c. and other operating voltages are available.

Electroswitch tagging relays provide an OSHA and National Electrical Safety Code accepted means to automate tagout functions at remote locations, enhancing safety while saving time and expense, explained Conklin

To ensure an uninterrupted flow and a high quality of parts, Electroswitch manufactures 90 percent of its own components in a modern, highly efficient machine shop and molding facility in Rockland, Mass. Electroswitch also has an on-site test lab to assure compliance with all applicable military, ANSI/IEEE, UL, CSA and power industry specifications, as well as to provide any special testing required for particular customer applications.

"Our Series 24 is one of the most widely used manual panel switches for instrumentation and control in North America' Conklin noted. "The reliable, high-speed Series 24 lock-out relay is an acknowledged industry standard for many critical safety applications."

Individualized nameplates incorporating bright, long-life LEDs are available for most Series 24 manual and remote operated products, eliminating the expense, labor and space impact of traditional panel-mounted lamps. And to meet the needs of automation in the modern utility industry Electroswitch has developed remotely operated, SCADA-compatible versions of the most popular Series 24 manual switches and lock-out relays. "The control switch, latching switch and selector switch relays along with a variety of electric reset lock-out relays are the automation devices of choice at over 100 electric utilities," Conklin said.

"In addition, Electro-switch provides Series 31 and Series 20 manual switches for power industry applications where small size is required. Series 101 snap switches are used to replace toggle switches where reliability is important," he added. "And now we provide the type Wand W2 switches and type WL and WL2 lock-out relays formerly manufactured by Westinghouse and we continue to service that enormous installed base."

Series 20 cam switches feature a very small footprint designed to reduce the space required on power industry control panels. These instrument and control switches can be mounted on 3 in. centers and can be built with up to 12 decks (24 poles) and up to 12 positions. All Series 20 models feature double break, silver-plated contact enclosed in rigid ther-moser plastic housings for long, reliable life. The standard Series 20 switches have a two-hole mount and provide a continuous rating of 24 amps at 600 V and interrupt ratings of 3A/ 125 Vd.c. or 20A/600 Va.c. Control switches have a mechanical red/ green target, slip contacts for alarm and indicator circuits, pullto-lock handles for safety lockout and spring return to normal position.

The Series 20 lighted switches have a four-hole mount and offer the same features and ratings as the standard Series 20 plus one, two or three pre- wired status indicator lamps for LEDs in a variety of color options.

For industrial markets, Electroswitch provides high quality, reliable switches to fulfill a variety of needs. Examples of this versatility include, ammeter switches, cut-in/cut-out switches, d.c. current switches, emergency shut-off switches, auxiliary generator control switches, locomotive cab heater control switches, engine testing control switches, transit and rail safety interlock switches and UPS system manual bypass control switches.