Breakers

Breakers are switches that isolate and protect separate electrical systems on motorized rail vehicles . Breakers are typically present on post-steam era rolling stock, and allow the electrical systems to be toggled on and off, individually. There are a few types of electrical systems:

Starter - This breaker enables ignition of internal combustion engines .

Electrics - This breaker enables accessories that run on electricity, such as compressors , lights and wipers . On steam locomotives, the equivalent of this breaker is the dynamo valve.

Traction Motors (TM) - This breaker enables traction motors on vehicles with electric powertrains . In case of overheating , traction motors can trip the breaker, which then needs to be manually re-enabled.