The pedal must be depressed at all times except when the locomotive is stopped and 30 pounds or more brake cylinder pressure exists. If the pedal is released during operation, the safety control whistle will sound for two to four seconds during which time the pedal can be depressed preventing brake action. Otherwise a full service application of brakes will be made. Dynamic brake interlock is furnished with dynamic brake equipment and is used to release or prevent an automatic brake application on the locomotive if the dynamic brake is on. Independent application and release of the locomotive brake. is available at all times irrespective of dynamic brake operation.
Railroads specify conditions that operate the interlock.
The switch is reset automatically as soon as the brake pipe is recharged or main reservoir air pressure drops below 40 psi. Railroads specify conditions that operate the switch. Move brake valve cut off valve to cut out position. At the engineman's control station, open control and generator field breakers leaving the fuel pump breaker closed. On some units equipped to MU with units of other manufacture, the control breaker must be left closed until control and fuel pump breakers are closed on unit being cut in.