Summary
Highlights
Powered equipment, while increasing productivity, can be dangerous due to its energy. Injuries often occur when equipment is inadvertently turned on while being serviced. OSHA's lockout/tagout regulations prevent such incidents by disabling machines during maintenance. This program will discuss these regulations and procedures for safely setting up, repairing, and maintaining powered equipment.
Lockout/Tagout (LOTO) aims to isolate machines from their power sources during servicing to prevent injuries. Locks, tags, and other devices are placed on energy isolation points like electrical switch boxes and valves. Lockout shuts off energy, while tags provide information about the work being performed. LOTO is crucial for repairing circuits, cleaning, lubricating, clearing jams, rebuilding, and setting up equipment. OSHA regulations mandate an energy control program, including written LOTO procedures and employee training.
Common LOTO devices include padlocks, chains, and valve clamps; specialized wedges and pins are used for hydraulic/pneumatic systems. Tagout devices visually warn that work is being done and identify workers and reasons for service. Tags only provide information and must be used with locks. Employers provide designated LOTO devices, which cannot be used for other purposes or shared. Devices must be identifiable, durable, and difficult to remove by accident.
Only authorized employees can install LOTO devices; they must recognize hazardous energy sources and control procedures. Affected employees, who work with or near serviced machines, need to understand the energy control program and be informed when LOTO is in progress in their area. Affected employees are not permitted to restart locked-out machines.
When locking out equipment, first notify necessary personnel. Then, proceed to lock out and tag the machine's energy sources using specific mechanisms for electrical panels, circuit breakers, and valves. Some facilities use a central storage for LOTO equipment and a logbook for authorized employees to sign devices in and out. Always follow company guidelines and energy control program procedures.
Equipment is powered by electrical, hydraulic, and pneumatic energy, existing in active (in use) or stored (waiting to be used) states. After initial LOTO, stored energy like battery charges, spring tension, or extreme temperatures must be dissipated. This might involve adjusting valves, installing blinds in piping, or grounding electrical systems. Block off moving parts and install additional LOTO mechanisms as needed.
After LOTO and energy dissipation, test the machine to ensure it won't operate. For electrical systems, use a voltmeter to confirm no current. Press all start buttons and activate switches/levers normally used to operate the equipment. Once confirmed safe, return switches to the off position. Work can then begin.
Personnel changes during servicing require incoming shifts to install their LOTO devices before departing shifts remove theirs, ensuring continuity of responsibility. When multiple machines share an energy source or are linked, supervisors must be contacted. If equipment must remain on while serviced (e.g., essential operations), supervisors must also be consulted. High-voltage systems pose arc flash risks: look for warning labels, consult supervisors, and wear appropriate PPE.
The buddy system is used when the power source is out of sight, with one person locking out and another observing/testing. For group work, LOTO devices allowing multiple workers to attach their locks and tags are used. One employee can represent a group if many groups are involved. Contractors must be informed of LOTO activities and must inform facility representatives if they are performing LOTO work.
To return a machine to service, remove non-essential tools, clear affected employees, and check the machine's readiness (e.g., no load on electrical circuits). Each employee who installed a LOTO device must personally remove it. In emergencies, management can remove a device if the employee is unavailable, but the employee must be informed afterward. After all devices are removed, test run the equipment. If testing from the LOTO location is not possible, use the buddy system.
For temporary restarts during prolonged shutdowns, follow normal release and restart procedures. After the temporary work, resecure LOTO devices. At the completion of any LOTO procedure, return locks and tags to their designated storage, signing them out in the log if applicable.
For electrical systems, circuits and fuse boxes must be locked and tagged. If standard devices aren't suitable for a fuse box, consult a supervisor. For multiple power sources, locking out a main panel might be necessary. After LOTO, attempt to start the equipment to confirm no movement. Test circuitry with a voltmeter. Remember to ground capacitors in electrical systems before working to drain stored charges.
LOTO for hydraulic and pneumatic equipment involves pipes and valves. The hazard is high-pressure release of steam, gas, or fluids. Use padlocks, chains, or valve clamps to prevent valve movement, then apply tags. Bleed pressurized lines to dissipate stored pressure. Pipe dividers (blinds) simplify LOTO for complex hydraulic systems by allowing segmented bleeding. Test effectiveness by cracking downstream valves to check for residual pressure.
Hydraulic and pneumatic systems often have heavy moving parts that can slip due to vibrations. Use wedges, blocks, or pins to secure these parts during LOTO. Physically isolate locked-out machinery with barricades to prevent accidental jostling from passing equipment, or arrange for the shutdown of nearby machinery if needed.
Lockout/Tagout is essential for safety. Identify all energy sources for the equipment. Each worker must attach their own LOTO device. Test equipment after locks and tags are in place. The person removing the last device must ensure work is complete and the machine is safe to operate. Common sense, communication, and knowledge of LOTO procedures are crucial for safety when working with powered equipment.