(4) Turn cover screw (2) counterclockwise until cover (1) is loose.
(5) Remove cover (1) and gasket (5).
(6) Check with multimeter for continuity across contacts (4).
(7) If continuity, then switch is closed.
(8) If no continuity, then switch is open.
(9) Bring pressure in ROWPU to point where contacts (4) close (from Table 2-4).
(10) Turn range screw (3) slowly clockwise until contacts just open.
(11) This sets the opening point from Table 2-4 to desired psi.
(12) If set point pressure is reached and contacts remain open then replace switch.
(13) For switch that closes on increasing pressure, follow same adjustment procedure except in step (10), turn
clockwise until contacts just close; and in step (11), this sets the closing point from Table 2-4.
(14) Install cover (1), gasket (5) and secure with screw (2).
Table 2-4. Pressure Switch Settings
or Close with
Product Water Pressure
High Pressure Pump Suction Pressure
(MODEL ROWPU-1 ONLY)
a. Remove screws (1, Figure 2-41.1) and cover (2) from switch housing (3).
b. Use a multimeter to check that power is being applied to the input power connection points inside the switch housing
c. If power is being applied to the terminals and the gages on top of the control panel indicate that the pressure switch
should be activated, attempt to adjust the switch in accordance with the next paragraph.
(MODEL ROWPU-1 ONLY )
a. Differential Switch
(1) Remove two screws (3) and cover (4).
(2) Locate the adjustment screw (5) on the bottom of the switch housing (6).
(3) Turn the adjustment screw (5) on the bottom of the switch housing clockwise to increase the pressure
(4) Turn the differential screw (5) counterclockwise to decrease the pressure difference.
(5) Gages on top of the control panel show the differential pressures (between black and red arrows on the dial
(6) The control opens a circuit on a change in the difference between two pressures. See Table 2-3 for correct
(7) Install cover (4) and two screws (3).
b. Pressure Switch
(1) Remove two screws (7) and (8).