10
44-604 Top Mounting Liquid Level Switches
4.0
Preventive Maintenance
Periodic inspections are a necessary means to keep your
level control in good working order. This control is a safe-
ty device to protect the valuable equipment it serves.
Therefore, a systematic program of “preventive mainte-
nance” must be implemented when the control is placed
into service. If the following sections on “what to do” and
“what to avoid” are observed, your control will provide
reliable protection of your equipment for many years.
4.1
What to do
4.1.1 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 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.
4.1.2 Inspect switch mechanisms, terminals, and
connections monthly
1. 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. See switch mechanism bulletin
supplied with control should switch adjustment or
replacement be necessary.
2. DO NOT operate your control with defective or mal-
adjusted switch mechanisms (refer to bulletin on switch
mechanisms furnished for service instructions.)
3. Level controls may sometimes be exposed to excessive heat
or moisture. Under such conditions, insulation on electri-
cal wiring may become brittle, eventually breaking or
pealing away. The resulting “bare” wires can cause short
circuits.
NOTE: Check wiring carefully and replace at the first sign of brittle
insulation.
4. Vibration may sometimes cause terminal screws to work
loose. Check all terminal connections to be certain that
screws are tight.
