[Hallb-engineering] Fwd: Lesson Learned: Hand Broken While Performing HVAC Maintenance - Information Only

Douglas Tilles tilles at jlab.org
Thu Jan 31 09:22:21 EST 2013

This is a good reminder to make sure equipment that is being worked on is secured. 

----- Forwarded Message -----
From: mbailey at jlab.org
To: mbailey at jlab.org
Sent: Wednesday, January 30, 2013 4:18:53 PM
Subject: Lesson Learned: Hand Broken While Performing HVAC Maintenance - Information Only

  FML-12-0918- Broken Hand While Performing HVAC maintenance 


Statement of Lessons Learned 

1. Ensure all moving parts have come to a complete stop prior to beginning your visual and hands-on 
2. Large moving parts create significantly more force, even when barely moving, than can be 
physically overcome or stopped by even a strong person. 

Discussion of Activity 

Contractors were tasked with performing routine maintenance on the exhaust fans located on the roof of the Applied Research Center(ARC) Building. The contractor was working with another contractor as a 2 man team. Contractor 1 was in charge of turning off the power to the fan variable speed drive located in the power supply room. Contractor 2 was responsible for securing power to the fan at the local disconnect and beginning the inspection process. Johnson Controls procedure states that that all power sources are cut off, and then they should execute the zero- energy check “try” step to ensure that the power was actually turned off then begin the inspection process. 

Contractor 2 secured power at the local disconnect, grabbed a ladder and proceeded to unbolt the pulley guard. He unbolted the top 2 screws, and then unbolted the bottom 2 screws to the pulley fan. He climbed back up the ladder and removed the guard from the pulley system. Contractor 2 stated that the pulley belts were barely moving when he grabbed the belt with his right hand to begin the hands-on pulley belt inspection. Upon beginning this inspection the belt pulled his right hand into the pinch point of the pulley and wheel system.  Contractor 2 responded by immediately pulling his hand from the pinch point and contacting Contractor 1.  Contractor 2 was later diagnosed with a fractured hand, requiring surgery for repair. 


The Contractor failed to follow their company's Hazardous Energy Control Program 

Contributing cause(s) include: 
- Failure to perform a zero-energy check “Try” on the power source before beginning the inspection process (Failure to “Try” the power source was a safety problem identified during investigation,but not “Trying” the power source before beginning the inspection process did not contribute to the incident unless the time required to “Try” the power source would be long enough for the fan wheel to come to a complete stop). 
- Failure to allow the pulley system enough time to come to a complete stop prior to starting the maintenance process. 
- Gloves may have been caught in the slots of the pulley. 
- The large mass of the exhaust fan wheel resulted in a great amount of inertia that though the belt movement appeared almost stopped provided significantly more force than what could physically be overcome or stopped by the mechanic. 

Recommended Action 

1. Contractor will retrain the local office (Norfolk) on the company's Hazardous Energy Control Program (Lock, Tag & Try procedure). 


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