I'm dealing with the same issue too. I checked the sensor on my ezpath and it looks like it NC but switches on on about 20 PSI. I'm looking for an oil leak in my case or may try to increase the stroke on the plunger to deliver more oil. The plunger is pulled by an intermittent motor that turns once ever few minutes. I think you may get the warning every time the pressure drops back below 20 psi say 5-10 minutes after the plunger is pulled by the motor. When I got my lathe last month the two sensor wires were disconnected.