Electric extinguishers
Stories from Physics
for 11-14
14-16
It is not uncommon for a user to receive a small shock when they touch a grounded conductor after discharging a carbon dioxide fire extinguisher. This is because charge can be transferred by the motion of the dry ice particles through the nozzle. As an extinguisher is likely to be used in a potentially explosive environment, it is recommended that discharge nozzles are grounded before use as an extinguisher can develop a potential of up to 30 kV during discharge.
References
T. J. Wysocki, Carbon Dioxide and Application Systems, A.E. Cote (Ed.) Operation of Fire Protection Systems Fire Suppression Without Water, Quincy, MA, National Fire Protection Association, 2003, 589-600, p. 590
G. J. Butterworth, & P. D. Dowling, Electrostatic effects with portable CO2 fire extinguishers. Journal of Electrostatics, vol. 11, no. 1, 1981, pp. 43-55.
