Scenario: A piece of equipment has twelve (12) energy sources, which must be isolated to get the piece of equipment down to a zero energy state (ZES). I have a task that will expose me to ONLY 1 of these 12 energy sources – can I just lockout the one (1) source or must I lockout all twelve (12) each time I perform this task?
This scenario is one that happens just about every hour in most facilities and yet many LOTO programs and training programs have never addressed it.
Yes, the easy way for the safety team to dodge the question is to claim all 12 sources must be isolated regardless of exposure and unfortunately, that has been the answer for decades and we then learn that because of this hardline position that now nothing is being locked out.
Early in the life-cycle of a LOTO program I ALWAYS take the hardline approach, but as a facility matures and comes to fully understand energy isolation/control I will begin to loosen the grasp and allow logical arguments to be made. This argument is always one of the first big hurdles to cross. This morning, I attempted to explain how a machine with multiple power sources could be worked on safely when only those sources with exposure to the worker being locked out and the other sources NOT under my exclusive control…
Your thinking is correct. There are a lot of machines that need multiple power sources to actually operate and be maintained properly. The food industry has a lot of packaging machinery that uses heat for glue sealing. If you shut down the machine for, say, more than 15 minutes, the glue chills and can become unusable, or it will take an hour to reheat it so it can flow.
So, in this situation, TWO (2) power sources are the answer. The main power will run the equipment, and a secondary power will go to the glue system. Sometimes, the glue would be put on a UPS battery device so as to keep the heating element energized when the machine would go down for any reason (even a legit power outage during a storm). These glue systems are oftentimes the sole bottleneck for starting up or restarting a machine!
But when you do this double power source, LABELING, PROCEDURES, and TRAINING become VITAL to safety. By this, I mean the glue system openings ALL had labels indicating a different power source for this equipment. I always used the attached label, and in some businesses, they wanted the labels to be machine-specific and actually call out the sources and where their disconnect(s) are.
Remember the golden rule of Energy Control… interlocks are NEVER actual energy isolation devices! They are intended to be part of the machine guarding system, not the maintenance and servicing side of the machine’s life cycle. The ONLY reason why OSHA ever allowed the “minor servicing exception” and the use of an alternative to locking out a machine was so that they could get 1910.147 promulgated. Without this one except, they were faced with not getting any part of this standard in place. So they compromised, and as we humans do, we bastardized the except to the point where we lost limbs and lives.
I can only imagine the influence the “Big 3” and all their Tiered suppliers had on MI-OSHA in this regard. Remember the famous GM LOTO decision from back in the 90s?
A contractor was killed inside a robot cage, OSHA cited GM for LOTO, GM fought it all the way to the full OSHRC and won the case based on the fact that there was a multi-stage startup with audible alarms, lights, etc., and because of these alarms at each stage it was not an “unexpected start-up.” If you have not read this decision, you should, but if you sit down and have a 6-pack by your side, you will be blown away. This decision has haunted our profession ever since – even GM safety leadership and Union leadership did not agree and have NEVER used the decision as a basis for how they approach LOTO.
So, to make it clear, you ONLY NEED to lock out the energy sources you are exposed to while performing the servicing and maintenance. If there are four (4) energy sources to a piece of equipment, and you need to do something that will expose you to only electrical, then only the electrical needs to be locked out. But this can cause (and has) some serious LOTO failures. With this, we allow the workers to pick and choose which sources they feel they should lockout, and oftentimes, they choose poorly! Remember the fillers at XXXXXXXXXXX? They had over a dozen lockout points, but many of the tasks would only need 1-2 sources locked out. I was trying to get them to update their procedures to state which sources had to be locked out for that specific task(s). Probably only 1-2 times a year would all 12 have to be locked out at the same time. As far as I know, they never did this. So what happens when they have an amputation and have to call OSHA? OSHA looks at the LOTO procedure and asks, “Why was this not followed when Mary was cleaning the screens?” Rightfully so, the facility will argue that not all 12 energy sources are a hazard when workers “clean the screens.” However, without a procedure (operating, maintenance, or LOTO) telling the worker(s) which sources of energy need to be isolated for specific tasks, OSHA will correctly cite 1910.147.
