10
47-602 F10 and F50 Flow Switches
3.0
Preventive Maintenance
Periodic inspections are a necessary means to keep your
flow switch in good working order. This control is a safety
device to protect the valuable equipment it serves. A
systematic program of preventive maintenance must be
implemented when the control is placed into service. If
the following is observed, your control will provide reliable
protection of your capital equipment for many years.
3.1
Recommended Practice
3.1.1 Keep Control Clean
Be sure the switch housing cover is always in place on the
control. This cover is designed to keep dust and dirt from
interfering with the switch mechanism operation. In
addition, it protects against damaging moisture and acts
as a safety feature by keeping bare wires and terminals
from being exposed. Should the housing cover, or any
seals become damaged or misplaced, obtain a replacement
immediately.
3.1.2 Inspect Switch Mechanisms, Terminals, and
Connections Monthly
a. Dry contact switches should be inspected for excessive
wear on actuating lever or misalignment of adjustment
screw at point of contact between screw and lever. Such
wear can cause false switch actuating levels. Adjust switch
mechanism to compensate (if possible) or replace switch.
b. DO NOT operate your control with defective or
maladjusted switch mechanism (refer to bulletin on switch
mechanisms furnished for service instructions).
c. Controls may sometimes be exposed to excessive heat or
moisture. Under such conditions, insulation on electrical
wiring may become brittle, eventually breaking or peeling
away. The resulting bare wires can cause short circuits.
Check wiring carefully, and replace it at the first sign of
brittle insulation.
d. Vibration may sometimes cause terminal screws to work
loose. Check all terminal connections to be certain that
screws are tight.
e. On units with pneumatic switches, air (or gas) operating
medium lines, subjected to vibration, may eventually crack
or become loose at connections causing leakage. Check
lines and connections carefully and repair or replace, if
necessary.
