On a dual air system bus, what is the minimum psi for the governor to cut-in?

The minimum psi for the governor to cut-in on a dual air system bus is set at 85 psi. This cut-in point is critical because it ensures that the air brake system has enough pressure to operate effectively and safely.

The governor is a vital component that regulates the air pressure within the system to maintain optimal functioning. When the air pressure drops to 85 psi, the governor will activate the compressor to build up pressure back to a safe operational level, preventing the braking system from becoming compromised. This threshold is particularly important for ensuring that the vehicle can safely stop and maneuver, which is crucial for school buses transporting children.

Understanding the proper psi settings is essential for maintaining the integrity of the air brake system and ensuring that it functions effectively during operation. Other options provided are either too low, which could result in insufficient air pressure for safety, or are not common industry standards for dual air system buses.