Traditionally, lockout/tagout is treated as a one-off encounter each time. Even if six maintenance electricians have each performed lockout/tagout on the same machine several times, the “new guy” seventh electrician will have to duplicate all their work. This often includes obtaining drawings, carefully going through them to identify all energy sources, and then physically locating them.
Properly and completely identifying all related energy sources takes time. People can feel that spending time doing this gets in the way of getting work done. This feeling is somewhat justified when lockout/tagout has been performed repeatedly on the same equipment, yet the wheel must be reinvented each time.
This leads to shortcutting the process (skipping steps, doing things from memory, or going with assumptions). It also means that each time this procedure is performed, there is danger of human error.
Tip 1: Do it once, audit, and publish.
Identify the equipment most likely to need maintenance or repair. If you have equipment history (for example, in a CMMS), create a report that sorts by most instances of equipment shutdown.
Starting with the highest number, have someone perform a lockout/tagout procedure for that equipment. Verify its effectiveness and completeness with measurements. Next, document what has been done and the location of each energy source. This document package is then attached to the asset number in the CMMS so the next person simply has to follow this sequence and verify with a meter. The document package should include the relevant drawings with the energy sources marked on them.
Going forward, anyone performing lockout/tagout on this equipment:
- Does not have to chase down drawings or spend time analyzing them. An assembled package of pre-marked drawings eliminates that rework.
- Will not introduce a human error such as missing an energy source, since these have already been identified in the plant and on the drawings.
- Re-verifies this specific sequence each time via measurement rather than creating a new sequence on the fly.
However, things change. Maybe since this procedure was documented, a variable-frequency drive was added, and it also must be locked out. You cannot completely rely on verification to flag that the procedure for this specific equipment is not complete because how will the electrician know what to test?
A good solution is to adopt the practice of using controlled drawings and controlled procedures. Any time a drawing related to an asset is updated, its lockout/tagout procedure is automatically flagged for review. Make it clear on the procedure the flag means the procedure is not considered current and complete.
Tip 2: Make it more easily lockable.
Why make someone open a panel, lock out a breaker (if it’s even lockable), and hang a tag in that crowded space? It is worse when three other crews have lockout/tagout going on in that panel. Where practical, create a lockout/tagout point with a disconnecting switch.
Use the same strategy where crowding of any sort can complicate lockout/tagout. Remember, it is a system not only of energy isolation, but also of communication. You need room for tags, not just locks. In some cases, multiple crews or departments will need simultaneous access to de-energized equipment. For lockout/tagout, that means hanging a hasp onto which individual locks then get hung.
If operations, a mechanic, two electricians, and three outside contractors need to hang their locks, do you really have room for seven locks and tags and possibly two hasps in that enclosure?
When lockout/tagout is not even an afterthought in equipment design and installation, it is never going to be efficient — and you are relying on luck that it will be effective.
Tip 3: Separate power and control.
Typically, lockout/tagout is primarily concerned with power sources and lockout/tagout of control sources is an afterthought. Although it is true that if you have no power you have no control, this doesn’t mean you should “save time” by ignoring the control sources. It is also true that if controls are locked to the OFF position, then you’re not going to accidentally operate any equipment. Use both layers of protection.
If you divide the job so that you identify and isolate the power and then turn your attention to controls (or vice versa), you are less likely to overlook something in either.
Another advantage of addressing these separately is that to understand which controls to lock out, you usually must understand how the system functions. This means as you review the drawings and walk through the operation (perhaps with the help of an operator), you will also see non-electrical sources of energy you had previously overlooked. Most of these are every bit as deadly as electricity.
In many cases, control lockout can be accomplished in software. The problem there becomes how to tag the lock. There is not, thus far, a standard answer that fits all situations. There are plenty of opinions on how to do this, but OSHA has not yet embraced software lockout as equivalent to mechanically locking something out. Treat this as an extra layer of protection, not as one that can replace mechanical lockout.
Tip 4: Light ’em up.
It is common to have barely adequate lighting at panels. One traditional solution was to request a project to add task lighting, and it was traditional for management to reject the project as unnecessary.
Another traditional solution was to run portable cords for temporary lights. This could easily add half an hour to the schedule, so having someone stand there with a flashlight often seemed more efficient.
A better solution is to buy battery-powered magnetic LED lights and stick one on each panel. These don’t cost much, and having one right there eliminates the problem of needing to make yet another trip back to the shop.
If there’s a suitable power source nearby, another solution is to permanently install LED strip lighting. This is inexpensive and easy to install, plus you don’t need to run raceway from that panel halfway across the building as you might to hang some fluorescent fixtures.
Tip 5: Reduce demand.
A lockout/tagout can’t go wrong if you don’t have to do it. Use a strong monitoring program to alert you to conditions that cause the failures that require lockout/tagout. For example:
- Power monitoring. The system alerts you to a voltage imbalance condition. While correcting this may require a lockout or two, it’s going to prevent replacing all of the motors on that feeder.
- Vibration monitoring. Bearing failure is the number one cause of motor failure. Causes include errors in lubrication methods, alignment deficiencies, and “soft foot” (from improperly tightening mounting bolts). The causes can often be addressed without lockout/tagout — especially if you pay attention to the advance warning and act promptly.
- Vibration analysis. With a premium capability vibration analyzer, a properly trained person can predict motor bearing failure months out from now. It’s worthwhile to hire a specialist to check all of your motors if you lack the resources in-house. You can tag that motor for replacement when a lockout/tagout of that motor or the equipment it drives is necessary for some other purpose.
- Insulation resistance testing. If you have automatic IR testers installed on motors where it’s practical to install them, then the failure prediction and scheduling advantage are similar to what you get with vibration analysis.
- Temperature monitoring. For critical motors and for motors that run in difficult applications, temperature monitoring can help prevent premature failure. Corrective measures can include filter changes, additional ventilation, gearbox oil changes, or even cleaning.
Tip 6: Train hard.
At many plants, the training for lockout/tagout seems to be based on the idea that good luck will attend every maintenance or repair job. Training must be more rigorous than that. If you’re using the “do-it-once” method, then you need three types of lockout/tagout training:
- The foundation, including why lockout/tagout is done and what the general rules are.
- Specific training for the “do it once” method with hands-on demonstration.
- Training for lockout/tagout where no “do-it-once” procedure exists.
If you follow the other five tips, then you will significantly reduce the time needed to perform lockout/tagout. Use some of that savings to better train people in how to perform lockout/tagout.
Thinking outside the lock
Reducing the need for lockout/tagout can pay big dividends. What tasks can be automated or done remotely? How can you leverage predictive technologies to schedule replacements and repairs in a way that “piggybacks” onto a scheduled task for that equipment and eliminate a duplicated lockout/tagout?
While lockout/tagout is only one of many safety concerns, it deserves more attention than it gets in many facilities. It can be more efficient and more effective than the traditional method of “doing it for the first time” every time. That means more consistency, lower cost, less room for human error, and increased safety.
Lamendola is an electrical consultant located in Merriam, Kan. He can be reached at [email protected].
