At what pressure should the governor automatically stop the compressor?

The compressor governor is an essential component of an air brake system that regulates the air pressure in the storage tanks. The correct pressure at which the governor should automatically stop the compressor is around 125 psi. This pressure level is a standard specification used in many commercial vehicles to ensure that the air brakes function effectively and safely.

When the air tanks reach 125 psi, stopping the compressor helps prevent excessive pressure buildup, which can lead to system failures or damage. Additionally, maintaining this pressure allows for adequate air supply in the tank for braking purposes, ensuring the air brakes are responsive and reliable when needed.

Using a lower pressure, such as 75 psi, would not provide sufficient air for braking, while a higher pressure like 150 psi may risk damaging components of the braking system or triggering safety valves. Therefore, setting the governor to stop the compressor at 125 psi strikes the right balance between providing adequate braking force and protecting the integrity of the air brake system.