Xylem MM 110C Series PFC 1G PFC 1GR Modulating Pneumatic Liquid Level Controls - Manual (Page 4)

4
When the control is placed in service, and after any
adjustment, make sure of proper air output. With
cover removed, and air supply turned on, check that
the output gauge shows a range from 3 to 15 psi
when the yoke is moved manually through a full arc of
travel. With the yoke in horizontal position, the output
should be approximately 9 psi.
If necessary to adjust: Loosen the two relay lock
screws (C). Turn knurled adjusting collar (D) until out-
put is 9 psi with yoke held in horizontal position.
(Rotate the collar clockwise, when viewed from the
top, to increase the output pressure or counter clock-
wise to decrease.) Tighten two lock screws securely.
To Adjust Air Output
For later reference, note proper orientation of control
mechanism with base. Slightly loosen clamp screw
(E), and slide control mechanism up or down on the
tower tube. If practical, adjust the level of the liquid to
desired control point, approximately 1” above the low
level mark on the float housing.
Make sure mechanism is in proper orientation with
base: the (M) yoke counterbalance weights should be
parallel to the back side of the base. Then tighten
clamp screw securely.
To Adjust Operating Level (Set Point)
START-UP AND ADJUSTMENT PROCEDURE (continued)
The position of the clamp screw must not be higher
than the top surface of the mechanism housing.
Positioning the mechanism too high may cause the magnets
to disengage, resulting in loss of output control.
! CAUTION
Loosen two locking screws at bottom of the proportional
band spring bracket (F). Turn the proportional band
adjusting screw (G) until the desired proportional band
is attained. (Screw is full out for factory-set maximum
band.) Tighten two locking screws in spring bracket
securely.
To Adjust Proportional Band
E
M
F
G
C
D
NOTE
This adjustment may require several small incremental
changes followed by operational checks before final setting
is achieved.