A hot stick is a tool (or probe) that first responders have used for years to prevent on-scene electrical injuries. It detects the presence of Alternating Current (AC) voltage in a wire or conductive material. A typical AC hot stick doesn’t work, however, for Direct Current (DC) voltage due to significant differences in the physics involved.
A new tool for DC voltage hazards
DC voltage is now found in a growing number of today’s technologies that first responders encounter, such as:
- Solar photovoltaic system installations.
- Electric vehicles.
- Fuel cells, power storage arrays and super capacitors.
- Mass transit applications.
These hazards require new tools to keep first responders safe from electrical exposures. That’s why the USFA is working with Oak Ridge National Laboratories to develop a better DC hot stick technology. DC detectors exist today but are so bulky and unreliable that they are unsuitable for field use.
The prototype DC hot stick (top) is shown with a commercially available AC hot stick.
Grounding clamp with positive confirmation of contact.
The USFA/Oak Ridge hot stick prototype is similar in appearance to most existing AC probes and familiar to first responders. It’s designed to slip onto the end of an AC probe. The prototype not only detects DC voltage, but it also ensures that the probe is properly tapped into the electrical lines being tested. This prevents false negatives. A green light indicates proper contact, and if voltage is detected, a red light is illuminated.
DC hot stick voltage probe inside a hybrid electric vehicle with voltage readout.
A patent for the prototype has been licensed and product testing is underway. We anticipate that a new product will be announced to the market soon.
Learn more about this research
For more information, please contact the USFA's Bill Troup at 301-447-1231.
This summary is for informational purposes only. As such, the content does not reflect any official positions, policies or guidelines on behalf of the sender, the U.S. Fire Administration, Federal Emergency Management Agency, the Department of Homeland Security, nor any other federal agencies, departments or contracting entities. Similarly, this summary does not represent in any manner an official endorsement or relationship to any private or public companies, organizations/associations, or any authors or individuals cited or websites associated within the article.
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: Gary Coronado / Los Angeles Times