Install Instructions

F76S WATER FILTERS AND MV876B AUTOMATIC-BACKWASH CONTROLS
33-00557—01 6
Fig. 5. Installing the F76S.
Fig. 6. Installing the MV876.
Installation on an F76A
1. Close the water supply valve to shut off water sup-
ply.
2. Drain all water from the F76A by opening both a
fixture downstream, and the backwash outlet;
loosen the air vent on top of the F76A.
3. Remove the backwash outlet (see Fig. 7):
a. Grip the F76A fixture with a wrench.
b. Using another wrench, turn the outlet counter-
clockwise (viewed from the bottom).
4. Connect the MV876 to the F76A (see Fig. 7):
a. Ensure a plastic washer is placed between the
filter sump and the backwash outlet.
b. Connect the externally threaded portion of the
MV876 backwash outlet to the internally
threaded F76A connection.
5. Connect the hose fitting to the MV876 backwash
outlet (see Fig. 7).
Fig. 7. Final position of MV876 and F76S components.
Set Pressure Gauge Needles
The black needle on the pressure gauge measures the
F76S outlet pressure. When the F76S is running with
clean screens, there is a small pressure drop across the
F76S (3 psi at maximum recommended flow).
The red needle is a stationary needle that helps monitor
backwash interval.
NOTE: The following assumes a constant inlet pres-
sure. If inlet pressure is variable, another gauge
on the inlet piping, or the air vent will provide
more information regarding actual pressure dif-
ferential.
1. Backwash F76S once to ensure the screens are
clean.
2. With the F76S in operation, rotate the clear gauge
cover to set the red needle to match the black nee-
dle.
As the F76S operates, screens become plugged.
Backwash the F76S when the black needle measures
about five psi lower than the red needle. However, each
M16481
MV876B
M16483
MV876B
M17357