12 VOLT/24 volt battery equalizer on bus

An NHTSA Preliminary Evaluation into Orion vehicles. Closed 31 May 2000.

Investigation
PE99075
Type
Preliminary Evaluation
Opened
8 December 1999
Closed
31 May 2000

What NHTSA investigated

ODI has received information alleging failure of the equalizer on the vehicles listed above.An equalizer provides a 12volt source from a 24 volt battery; in effect, two 12 volt batterier get equally charged in series from a 24 volt source, and equally discharged in parallel into a 12 volt load.The equalizing term refers to the distribution of charge and discharge energy between the two separte 12 volt batteries. When the failure occurs the equalizer smokes excessively, filling the bus with smoke.As these buses may be carrying 50 or more people, excessive smoking (with possibility of a fire) is a concern.A fire may also result.A preliminary evaluation is being opened to gauge the scope of the issue, the technical causes of the equalizer failures and to address the resulting public safety concerns.

Vehicles covered

MakeModelModel years
OrionV1998
OrionVI1998

Source

From NHTSA’s investigation file, rebuilt daily. To report a problem with your own vehicle, go to nhtsa.gov/report-a-safety-problem. All open investigations.