What is the operational pressure for the second switch in the brake accumulator?

The operational pressure for the second switch in the brake accumulator is correctly stated as closing below 1500 psi and opening above 1900 psi. This pressure differential is crucial for the proper functioning of the brake system in vehicles like school buses.

In a hydraulic brake system, the accumulator is designed to store hydraulic fluid and maintain pressure for braking functions. The second switch serves as a safety and control mechanism, ensuring that there is enough pressure in the system for effective braking. If the pressure falls below the specified range, the switch will close, indicating that the pressure is insufficient. Conversely, when the pressure exceeds the upper threshold of 1900 psi, the switch will open, allowing the system to regulate pressure and prevent over-pressurization.

The choice outlines optimal pressure settings that align with common specifications found in hydraulic brake systems. Utilizing the correct pressure settings enhances the reliability of the braking system, providing necessary feedback to the driver about the health of the braking mechanism. Understanding these specifications is vital for technicians responsible for maintaining and troubleshooting braking systems in school buses.