Pentair AUTOTROL MAGNUM 742 Installer Manual page 23

3.5.4.3 Breakaway switch cam instructions
Based on the system requirements and the external devices used, determine the program timing, ie.,
when the external devices need to operate, either open or close.
Typical external devices would be solenoids, solenoid operated diaphragm valves, relays, and
chemical feed pumps. Using the instructions below, sections can be removed from the breakaway
cam to allow signalling during the desired cycles. One cam can be used to signal multiple non-
contiguous cycles.
No.
Determine which breakaway cam sections need to be removed using the chart below. In
order to assure that switch deactivation occurs, at least three sections must be removed
from the breakaway switch cam.
The sections should be removed in a clockwise fashion, starting with the first number and
ending with the second (see picture 1). Utilizing the timing chart on the back, determine if
the switch arm should be riding on the cam [actuated] or not [relaxed].
Cycle
A
Service (C0)
Backwash (C1)
Brine (C2)
Slow rinse (C3)
Fast rinse (C5)
Refill (C8)
Tip
Remember that the switch operates either normally open or normally closed depending
upon how it is wired.
Using diagonal cutters or a razor knife, cut through the cam on either side of the section
you wish to remove. The breakaway cam section should be trimmed to the edge of the
B section which is to remain on the breakaway cam, see picture 2.
Cut the outside ring first, then at the score line on the bottom of each section near the
center ring.
Tip
When starting to remove sections, start two or three sections before the section required.
Then remove one section at a time until the required section is reached. This procedure
eliminates the potential of damage to usable sections.
When all of the desired sections have been removed, add the breakaway switch cam(s) to
the camshaft after the B1/B2 pilot cam.
C
The switch cam can be installed onto the camshaft in only one direction. The numbers on
the breakaway switch cam should face the controller.
Replace the standard pilot cams in the proper order and reinstall the camshaft onto the
D control valve. Refer to 9.6.7. Motor replacement, page 78 for instructions on the removal
and replacement of the camshaft assembly.
Ref. MKT-IM-012 / C - 25.10.2019
Installer Manual Magnum 742-762 - Description
Operation
Section numbers
19, 20, 21, 22, 23, 24, 25
26, 27, 28, 29, 30, 31, 32
33, 34, 35, 36, 1
2, 3, 4, 5, 6, 7, 8, 9, 10
11, 12, 13, 14
15, 16, 17, 18
23 / 106