NSLS ESH Highlight #30

Electrical Shock

Date: July 2, 2002
Editor: R. Casey, N. Gmür

Recently, an NSLS beamline user experienced a potentially serious electrical shock. The user experienced pain in both forearms and received minor burns to both thumbs. The incident was classified as a “Near Miss”, and attracted wide attention within the Laboratory and at DOE Headquarters. In the incident, operational difficulties in monitoring sample temperature led to an attempt to measure DC current by placing a conventional multimeter in series with the power supply and heating unit. In the configuration that was established, a low current/low voltage BNC connector became energized at 1000 VDC and the user was shocked when he touched the connector. More details of the incident are available at: http://www.nsls.bnl.gov/esh/highlights/pdf/critique_hilite30.pdf.

There are three important lessons-learned from this incident that staff and users must take very seriously:

• Do Not Work “Hot”
  
  The electrical configuration that was established had several known exposed and energized surfaces above 50 volts, in addition to the unexpected surface on the BNC connector. Working “hot” on such energized equipment is expressly forbidden at the NSLS unless the Department Chair has previously approved such work. This requirement is covered in both BNL and NSLS Facility Specific Training. It is imperative that this requirement be adhered to. More information on electrical safety requirements can be found in the NSLS ESH PRM 1.5.0 “Electrical Safety.”.



• Have Significant Changes Reviewed Before Implementation
  
  An important part of the NSLS safety program is the requirement for review of significant changes that take place in the workplace and at beamlines. We expect any significant changes of this type to be reviewed with us to ensure that safety standards are adhered to and that work can be performed safely. In this incident there was no discussion with anyone of the operational difficulties and the solution that was developed to address it.
  
  Discuss anticipated changes with:
  
  - for beamline configurations, contact Lonny Berman (x5333);
  - for experiment set-ups, contact Andrew Ackerman (x5431);
  - for electrical configurations, contact John Aloi (x7018).



• Report electrical shocks and other injuries to your supervisor or to the Control Room (x2550).

The most important step starts with you!

These lessons-learned are very important to remember and to put into daily practice. NSLS and beamline staff should emphasize these important issues to short-term users. Excellent safety performance is an essential for the NSLS and its future. Incidents of this type can seriously injure one of our employees or users and result in a significant impact to the operation of our facility. It is important that all work be done safely and in compliance with NSLS and BNL standards.