Solving Safety Hazards and Shortcomings with Switch-Rated Plugs and Receptacles

A Q&A with MELTRIC.

Q: Tell us a little about MELTRIC

MELTRIC is best known for manufacturing industrial UL/CSA listed Switch-Rated plugs and receptacles that feature DECONTACTOR™ technology and push-button circuit disconnection for enhanced user safety and electrical performance. The technology behind our Switch-Rated products was developed specifically to address the shortcomings and safety hazards that occur with the use of traditional plugs and receptacles.

In 1952, following the observation of an accident with a pin and sleeve device, Gilles Marechal devised a device that combined silver-nickel butt contacts and the load making and breaking capabilities of a switch in the convenience of a plug and receptacle. MELTRIC licensed this technology in the early 1980s and has become the North American safety leader in the electrical product manufacturing industry.

MELTRIC also manufactures other safe and reliable industrial plugs and receptacles including multipin, high amperage, single pole, and hazardous location devices. Additionally, we use our devices and third-party components to produce custom power distribution units, including portable rubber boxes, mobile or stationary multigang steel enclosures, dual voltage wall boxes, circuit protected receptacles, and more.

Q: Tell us about MELTRIC’s Switch-Rated Plugs & Receptables

Our Switch-Rated plugs and receptacles combine the safety and functionality of a disconnect switch with the convenience of a plug and receptacle. Their exclusive design allows users to safely make and break connections under full load (up to 200 A) and provides significant protection in overload and short-circuit conditions.

They feature a dead-front design and enclosed arc chambers to ensure that the load is safely disconnected and that all live parts are isolated and inaccessible before the plug can be removed. This design guarantees that users are always protected from exposure to live parts and potential arc flash while making and breaking connections.

Q: Are they UL/CSA rated and why is that important?

Yes, MELTRIC Switch-Rated devices are UL/CSA rated. To achieve their UL 2682 switch ratings, they have passed tests that far exceed those of ordinary plugs and receptacles. These tests include horsepower/locked rotor overload tests from the UL 508 standard for Industrial Control Equipment and electrical endurance and short-circuit make-and-withstand testing from the UL 98 standard for Enclosed and Dead-front Switches.

With their UL/CSA ratings for “Branch Circuit Disconnect Switching” up to 200 A and “Motor Circuit Disconnect Switching” up to 100 hp, they are an approved NEC disconnect switch eliminating the need for ancillary disconnect switches.

Q: What types of environments and/or applications should these plugs & receptables be used for?

The modular design and numerous mounting accessories of our Switch-Rated plugs and receptacles make it easy to configure them for use in a wide variety of applications. They can be used as in-line connectors/switches, mounted on wall boxes, overhead cord drops in busway systems, distribution panels, or even directly on equipment.

Their modular design makes it simple to install them as “line of sight” disconnects exactly where they are needed. Plus, they eliminate the hassle of finding convenient mounting locations for spacious interlocks and auxiliary disconnect switches required with other connectors.

They have been performance tested for over 6,000 trouble-free operations with highly consistent electrical connections and their critical hardware is made of stainless steel to protect against the effects of corrosion. Reinforced polyester and aluminum alloy casings are used to provide excellent impact resistance as well as protection against UV radiation and most harsh chemicals found in typical industrial applications.

Switch-Rated devices also offer Type 4X/IP69/IP69K watertightness as soon as the plug is latched to the receptacle, or the receptacle lid is closed. These products provide enhanced protection against windblown dust or rain, splashing water, and hose-directed water.

Q: Will these plugs & receptables increase productivity, reduce downtime, and/or operating costs?

Yes! All of the above.

Increase productivity with faster changeouts. Using MELTRIC devices to connect equipment helps to protect users from electrical hazards that are common with hardwired connections and other types of connectors. MELTRIC devices allow qualified persons to safely make/break electrical connections; specially trained electrical personnel may not be required on-site.

Downtime can be reduced by having replacement motors and equipment pre-wired with our Switch-Rated devices. They can be installed with plug and play simplicity reducing change-out downtime by 50%, allowing mission-critical processes to get back in operation faster.

Using our Switch-Rated devices to connect motors and other equipment helps improve your bottom line by reducing equipment, installation, and operating costs. Improved safety reduces accidents, injuries, and related costs. Faster change-outs reduce lost production during downtime. And plug & play simplicity improves maintenance personnel utilization by allowing electrical work to be performed more quickly and conveniently back at the electrical shop.

Q: How will these eliminate hazards and/or arc exposure?

DS and DSN Series Switch-Rated devices have safety shutters that close over the receptacle contacts before the plug can be removed. Users have no exposure to arcing or direct access to live parts at any time during or after the removal of the plug.

To remove a plug from a receptacle, the plug must be rotated 30° counterclockwise in the OFF position. This rotation of the plug automatically closes and locks the safety shutter, creating an insulating barrier between the plug and receptacle contacts before the plug can be removed.

The safety shutter can only be opened by the insertion and rotation of an electrically compatible plug. Twenty-four different keying arrangements ensure that only electrically compatible plugs can be inserted into a receptacle.

Q: What are the most important takeaways you want readers to know about your plugs & receptacles?

MELTRIC is dedicated to operator safety. Every electrical device we manufacture is engineered with user safety in mind. Our products help eliminate electrical safety concerns common with other types of plugs and receptacles, including hazards due to exposure to arcing and live contacts, contact degradation, water entry, and terminal failure.

We are committed to quality. All MELTRIC plugs and receptacles are tested and compliant with applicable UL/CSA standards and help users comply with NEC/CEC code requirements as well as NFPA 70E and other safety standards. International configurations are also available and comply with CE and IEC standards.

Anyone who is interested in MELTRIC plugs & receptacles can try out a DSN20 or DSN30 for free! Visit us online at meltric.com/offer to request a sample.