46-624 Series 3 Liquid Level Switches ASME B31.1 Construction
11
4. 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 at the first sign of
brittle insulation.
5. Vibration may sometimes cause terminal screws to loosen.
Check all terminal connections to be certain that screws
are tight.
6. Conduct a continuity test for switch contacts using a low
voltage DC circuit with an indicator.
7. Switches that are corroded or that failed the contact
continuity test should be replaced. DO NOT operate
your control with defective or maladjusted switch
mechanisms (refer to bulletin on switch mechanisms
for service instructions.)
8. Verify that switch housing cover and conduit seal are
properly closed after each inspection of the switch
mechanism(s).
NOTE: In applications with presence of salt-laden air or corrosive
vapors, contact MAGNETROL for possible alternate switch
mechanisms.
4.1.2 Switch and Wiring Inspection
The switch mechanism and supply wiring need to be in
proper position to assure correct switch operation.
1. Remove switch housing cover to inspect the supply wires.
2. Check that the supply wires are attached to the terminal
block and run under the baffle plate. Be certain that excess
wire does not interfere with the actuation of the switch
and that adequate clearance exists for replacement of
switch housing cover.
3. Manually push on the magnet of the switch mechanism to
confirm that the mechanism pivots freely. If it does not,
the switch mechanism should be replaced.
4. Make sure the switch mechanism is seated all the way
down on the baffle plate. Refer to
Figure 11
. Check that
the mechanism clamping screw is tightened to assure that
the mechanism is secured to the enclosing tube and in
proper position on the baffle plate. Refer to
Figure 12
on
page 12. The baffle plate should rest on the housing base
casting hub.
Switch wires
Switch
mechanism
clamping screw
Snap
switch
Adjustment
screw
Terminal
screws
Supply wires
Switch wires
Switch
mechanism
clamping screw
Terminal
screws
Supply wires
Snap
switch
Adjustment
screw
Figure 9
Figure 10
Switch
mechanism
Baffle
plate
Housing
base
Enclosing
tube
Housing base
casting hub
Figure 11