The larger nut on the larger spring in the pump pressure switch: changes cut-in AND cut-out simultaneously moving them both up (higher pressure) or down (lower pressure). This is the range adjustment nut.
It has the practical effect of raising or lowering the operating pressure range of the pump pressure switch. So if your switch was running at 20/40 (on at 20 psi off at 40 psi), and you tighten this nut 3 1/2 turns, you'll increase both numbers so that the switch will now operate at 30/50 (on at 30 psi and off at 50 psi).
Usually the larger nut in the pump pressure control switch (green arrow in our photo at left) adjusts the pump cut-on ("cut-in") AND pump cut-off pressures simultaneously.
It has the practical effect of raising or lowering the operating pressure range of the pump pressure switch. So if your switch was running at 20/40 (on at 20 psi off at 40 psi), and you tighten this nut 3 1/2 turns, you'll increase both numbers so that the switch will now operate at 30/50 (on at 30 psi and off at 50 psi).
Usually the larger nut in the pump pressure control switch (green arrow in our photo at left) adjusts the pump cut-on ("cut-in") AND pump cut-off pressures simultaneously.
