When a piece of equipment is tagged out, this tells other workers not to operate any switch, valve, or other energy source related to it. When it’s locked out, they can’t.

There is usually a lengthy chain of command that must be followed to lockout, tagout, and restart the unit. The chain of command is even lengthier to override a lockout.

When I worked as a technical writer at an electric utility company, the first step of every Maintenance Standard and Procedure I wrote was, “Make sure that proper lockout/tagout procedures have been carried out.”

To make sure I understood why it was so important, I was shown the spot at the far end of a boiler in a power plant, where a utility service tech had been “toasted” some years before when he opened the unit up for inspection. The power supply for the unit had not been locked out.

Tech safety

“When working with hvac, you’re working in an area of some sort of risk, such as ventilating hazardous materials, working with scrubbers and chemicals, high voltages, moving parts, or any stored energy,” explained Jay Kupec, loss control director, Robinson Mechanical, Boulder, CO.

“Each tech needs to have a good working knowledge and understanding of the lockout/tagout policy; it is for their personal protection and the protection of others,” he continued.

Some contractors contend that “lockout” is preferable to “tagout” if you live in a state that offers a choice. This is understandable, since locking out the equipment means just that; a person would physically need to remove the energy-isolating device before the energy could be restored.

However, “We work in a global economy,” Kupec pointed out, “in which we have several different languages, not just Spanish and English. With this in mind, if you use a tag and a person cannot read it, the power could be turned back on, causing an injury, illness, or death. With the lock and the tag it is almost impossible to turn it back on.”

Some systems have two ways to turn the system on. These are called parallel systems. “Again, it is important to lock and tag out” this system, Kupec says. “When you cannot see the power switch or switches, you need to lock and tag out.”

Exceptions, examples

At some jobsites, such as hospitals, techs need to know which systems must stay on. They should not be locked out.

“I know of two systems that are locked and tagged on to keep people from shutting down the system because of what it is ventilating,” said Kupec. “An example would be a ventilation system in a TB room. Or an area that has large amounts of ammonia stored or used inside a structure. The system is locked on to ventilate out hazardous chemicals.”

He explained that for an hvacr tech, the consequences of not using lockout/tagout range from relatively minor injuries, such as “getting a finger in a fan, or small amount of exposure to a chemical, to serious laceration of hand/finger or electrical shock pull-back injuries; or exposure to hazardous chemicals.”

Then there are the more serious injuries: loss of a hand, finger, or arm; electrocution; lifetime suffering from exposure to a chemical or disease (as would be the case with TB exposure); and the outright catastrophic, such as would occur from “not ventilating a product out of a building, killing the occupants,” Kupec said.

Why risk even the loss of a finger? Make sure that techs are fully aware of lockout/tagout procedures required in commercial-industrial work.

It’s the law. But more than that, it’s just good sense for safe service.