Page 15 - Occupational Health & Safety, April 2019

ELECTRICAL SAFETY
Taking the Guesswork Out of De-Energizing Industrial Equipment
New solutions expedite the lockout/tagout process and provide clear line-of-sight disconnect for operators.
BY TOM BERANEK
www.ohsonline.com
APRIL 2019 | Occupational Health & Safety 11
Lesson one when it comes to working with any type of electrical equipment is that a switch in the “off” position doesn’t necessarily mean it is truly “off.” As several recent product recalls
have demonstrated, some hard-wired switches have the potential to supply power even when the handle is in the “off ” position, posing a serious risk of shock or electrocution to both the switch user and any down- stream equipment operator.
National Fire Protection Association standard 70E requires that electrical equipment should always be de-energized before being worked on unless there is a compelling reason not to. In most all maintenance situations, workers must prove the absence of power prior to working on or near electrical components. The practices and procedures used to disable machin- ery or equipment and prevent the release of hazardous energy, called lockout/tagout (LO/TO), prevent more than 100 fatalities and tens of thousands of injuries annually, according to data from the Occupational Safety and Health Administration (OSHA).
Properly complying with LO/TO procedures may require donning cumbersome personal protective equipment and opening the switch to manually probe wires using a volt meter to confirm zero power. While time-consuming, taking shortcuts in this process can lead to serious injuries.
In accordance with National Electric Code, any motor application requires that the motor have its own shutoff. The estimated replacement time for an elec-
tric motor is one to three hours and involves multiple tradespeople, due to code and safety requirements.
A Switch is in Sight
One way to address these time and labor challenges is to utilize switch-rated plugs and connectors listed un- der UL 2682. Unlike standard connectors, devices list- ed under UL 2682 can operate as switches and be used to disconnect loads, even when energized. Spring- loaded silver-alloy contacts provide switching capa- bilities similar to a circuit breaker or contactor, with the connector remaining engaged during operation to protect users from arc flash and contact with live elec- trical components. A two-step connector operation places the plug in a rest position after disconnection, requiring a rotating motion to remove the plug while simultaneously closing the receptacle shutter.
Sections 430.102 - 430.109 of the National Electric Code (NEC) require approved disconnecting means to be located in a readily accessible location within sight of the motor location and driven machinery. This can often be a challenge because disconnect switches can be difficult to locate near machinery due to space or mounting constraints and/or require elec- tricians to perform this task.
With a switch-rated connector system, the plug being separated from the receptacle provides visual proof that power has been removed and displays fast and positive compliance with NEC requirements for de-energizing industrial equipment.
This technology provides workers a simple and efficient way to safely de-energize equipment and perform LO/TO. Workers injured on the job from exposure to hazardous energy lose an average of 24 workdays for recuperation, and one safety incident can cost millions of dollars in lawsuits, lost man- hours, OSHA fines, and negative publicity. This tech- nology also enables faster maintenance and equip- ment changeovers, leading to improved production uptime and efficiencies.
Planned Maintenance: Reducing Downtime
Planned maintenance is on the rise across all U.S. industrial markets, such as food and beverage and most notably in the oil and gas industry, where U.S. refiners spent more than $1.26 billion on scheduled plant outages, turnarounds, and shutdowns in 2018, an increase of 38.5 percent compared to the year pri- or. With oil refineries and chemical facilities in North America relying on an average of thousands of electric
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