During a PCS open condition, how long will the engineer have use of the dynamic brakes?

During a PCS open condition, how long will the engineer have use of the dynamic brakes?

• A. Until speed is reduced below the effective range of the dynamic brakes
• B. Indefinitely
• C. 20 seconds
• D. Only while the PCS is open

Answer: (A)

Dynamic braking works only within a specific speed range—the brakes generate significant braking force when the train is above a lower threshold, but become ineffective below that point. In a PCS open condition, you can use the dynamic brakes as long as the speed stays within that effective range. Once speed drops below the lower limit of the dynamic brake’s range, the braking effect diminishes and the system no longer provides useful dynamic braking. So the engineer will have use of the dynamic brakes until speed is reduced below the effective range of the dynamic brakes.

Dynamic braking works only within a specific speed range—the brakes generate significant braking force when the train is above a lower threshold, but become ineffective below that point. In a PCS open condition, you can use the dynamic brakes as long as the speed stays within that effective range. Once speed drops below the lower limit of the dynamic brake’s range, the braking effect diminishes and the system no longer provides useful dynamic braking. So the engineer will have use of the dynamic brakes until speed is reduced below the effective range of the dynamic brakes.