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46-622 Series 3 Liquid Level Switches ASME B31.3 Construction
4.2 Troubleshooting
Usually the first indication of improper operation is failure
of the controlled equipment to function, i.e., pump will
not start (or stop), signal lamps fail to light, etc. When
these symptoms occur, whether at time of installation or
during routine service thereafter, check the following
potential external causes first:
• Fuses may be blown
• Reset button(s) may need resetting
• Power switch may be open
• Controlled equipment may be faulty
• Wiring leading to control may be defective
If a thorough inspection of these possible conditions fails
to locate the trouble, proceed next to a check of the
control's switch mechanism.
1. Pull switch or otherwise disconnect power to the control.
2. Remove switch housing cover.
3. Disconnect power wiring from switch assembly.
4. Swing magnet assembly in and out by hand to check care-
fully for any sign of binding. Assembly should require
minimal force to move it through its full swing.
5. If binding exists, magnet may be rubbing enclosing tube.
If magnet is rubbing, loosen magnet clamp screw and shift
magnet position. Retighten magnet clamp screw.
6. If switch magnet assembly swings freely and mechanism
still fails to actuate, check installation of control to be
certain it is within the specified 3° of vertical.
7. Examine the switch closely as described in Inspect Switch
Mechanisms, Terminals, and Connections Monthly, Section
4.1.2, step 1 on page 10. Check continuity of switch with
ohmmeter. If switch does not function properly, replace it
immediately.
8. If switch mechanism is operating satisfactorily, proceed to
check sensing unit.
NOTE: Spare switches should be kept on hand at all times.
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