[Hallb-engineering] Fwd: Lesson Learned "Failure to Identify Secondary Power Source Leads to Worker Exposure to 480V - Mission Support Alliance, LLC"
tilles at jlab.org
Thu Mar 13 06:45:52 EDT 2014
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From: mbailey at jlab.org
To: mbailey at jlab.org
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Sent: Wednesday, March 12, 2014 5:01:23 PM
Subject: Lesson Learned "Failure to Identify Secondary Power Source Leads to Worker Exposure to 480V - Mission Support Alliance, LLC"
Failure to Identify Secondary Power Source Leads to Worker Exposure to 480V - Mission Support Alliance, LLC
Statement of Lessons Learned
For a copy of the original report, see Attachments on Lessons Learned page.
Perform a circuit confirmation on electrical components when they are located in an enclosed work space.
A Controlling Organization Administrator (COA) and an Authorized Worker used an Eight Criteria Checklist to Lockout a HVAC heating unit prior to work. They did not test the electrical components inside the enclosed cabinet and therefore did not verify the equipment�s single energy source. This lead to the worker being exposed to 480 volt power generated from a second source and could have resulted in serious injury. Discussion of Activities
On November 14, 2013, a COA determined that electrical work on a HVAC unit required Lockout/Tagout (LOTO) and assumed that it could be performed using an Eight Criteria checklist per DOE-0336, Hanford Site Lockout/Tagout Procedure. While performing the mandatory walk-down, it appeared that a single local disconnect to the HVAC unit was the only power source.
The Authorized Worker performed a safe-to-work check at the disconnect load side of HVAC unit (local disconnect) and at the Control Panel and found zero energy. The Eight Criteria checklist was completed and a LOTO was performed.
The Authorized Worker removed a portion of his Personnel Protective Equipment, opened the HVAC cabinet and discovered a molded case breaker located inside. He performed a safe to touch check by placing a meter on top of it and discovered energized 480 volt AC power. At this point he stopped work and contacted the supervisor, informing him of the discovery.
Signage, stating "Danger Heater Disconnect Located Inside this Panel Fed from Panel F/5 Elec. Equipment Rm," was later found lying on the roof top. Analysis
The supervisor had checked an on-line history data base (informal system) for previous LOTO issued for the HVAC unit and discovered that the eight point criteria had previously been used to perform work on the unit. Based this, the assumption was made, that the eight point criteria could be used versus a more rigorous LOTO process.
The supervisor did not obtain the drawing or the Electrical One-Line Diagram to ensure "Readily Identified" criteria was met because he assumed that drawing review was only performed when using the more formal process.
The supervisor did not have the necessary experience to be familiar with the equipment on which the work was being performed
The supervisor also did not have the practical experience necessary to prompt him to investigate the work location and adequately verify the energy source during the field walk down. Recommended Actions
Below are the consequences of the above event. They are provided for information and discussion purposes only.
Multiple power source electrical systems/components, including HVAC units are to be identified and labeled.
Enter and maintain accurate information in computer software tools used to support the work management process, including worker feedback from previous work evolutions.
Verify that Controlling Organizations and Authorized Workers are adequately trained and familiar with proper execution of circuit confirmation during electrical hazard isolations.
Establish and maintain a process for checking and maintaining equipment labels for electrical equipment. This could be done by adding to the Preventative Maintenance work process.
3/12/2014 4:44:22 PM by Bailey, Mary Jo
Submitted to those current in:
�SAF603A: ELECTRICAL SAFETY AWARENESS
�SAF604: HIGH VOLTAGE IN R&D
�SAF603N1: Arc Flash: Safety Awareness (ELEDEFV)
Summary Lesson ID: 802
Doc ID: 2014-JLAB-802
Safety Related: YES
Originator: Bailey, Mary Jo
Issued: 3/12/2014 4:36:34 PM
Approved By: Bailey, Mary Jo
Approved On: 3/12/2014 4:44:22 PM
Contact: Gerald Whitney 509-372-2166
Queued Emails: 0
Sent Emails: 0
Viewings: 2 times Attachments
* DOE Lessons Learned - Electrical6.pdf
* SAF603A: ELECTRICAL SAFETY AWARENESS
* SAF604: HIGH VOLTAGE IN R&D
* SAF603N1: Arc Flash: Safety Awareness (ELEDEFV)
* *Division Safety Officers (DSOs)
* *Safety Wardens
* *DOE Notification
* *ESH&Q Liaisons
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