Schneider Electric 9013FHG54J59M1X Pressure Switch

Schneider Electric's Square D 9013FHG54J59M1X is a four-port pressure switch for air compressors that combines an on-off lever with an integrated unloader valve and a four-port manifold to simplify wiring and plumbing. It is configured for a 135–175 psi cut-in/cut-out range (factory setting 135 psi cut-in, 175 psi cut-out for the J59 code), with a maximum system pressure rating up to 230 psi and a differential around 40 psi. The unit uses a 1/4" FNPT connection and is part of the 9013FHG family designed for automatic pressure regulation with unloading capability. Typical applications include controlling small to mid-size air compressors, where the unloader valve aids rapid restart by venting tank pressure when the switch shuts off, and the four-port manifold allows multiple lines to be connected.