Midmark® 1000 Pressure Switch Test and Repair
The pressure switch is located in the middle compartment accessed from the back of the cart. When the storage tank is filled to the preset pressure the pressure switch will open and stop the compressor.
Cut-In / Cut-Out time is the minimum and maximum discharge pressures at which the compressor will switch from unload to load operation (cut-in) or from load to unload (cut-out). The pressure switch controls the Cut-In and Cut-Out times.
Pressure Switch Adjustment
1.Run compressor until pressure reaches 100 PSI. Compressor should shut off close to 100 lbs.
2.If compressor didn’t shut down at 100 PSI, access pressure switch and remove cover. Refer to: Middle Compartment
3.Turn Adjustment screw A clockwise to increase both Cut-In and Cut-Out pressure. Turn Differential pressure adjustment screw B clockwise to increase Cut-In pressure without affecting Cut-Out.
