Carrier HH19ZA135 Limit Switch Refrigerant 'Open on Fall' or 'Open

'Open on Fall' or 'Open Low' means the SPST contacts will break the circuit when the pressure drops to your set point

With a voltage rating of 440 VAC

the transformer is likely nearing end-of-life and requires replacement to prevent ignition delay

standard pressure switches may fail to close due to lower air density

this specific model is designed for 120V control circuits

Carrier HH19ZA135 Limit Switch Refrigerant 'Open on Fall' or 'OpenFor contractors servicing Carrier residential and light commercial equipment, the Carrier HH19ZA135 Limit Switch is a critical safety component designed for precise thermal monitoring. This fixed temperature furnace limit control features an L135 40F calibration, meaning the contacts are normally closed and will open on a temperature rise at 135F, automatically resetting once the temperature drops below the 40F differential. This genuine OEM Carrier