46-624 Series 3 Liquid Level Switches ASME B31.1 Construction
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7. On installations without shutoff valves, relieve pressure
from vessel and drain off liquid head above control
mounting level.
NOTE: Control chamber, connections, and pipe lines need not be
removed from vessel or boiler.
8. Remove switch housing assembly by loosening enclosing
tube hex nut, which is located immediately below housing
base. Refer to
Figure 6
on page 8.
9. With switch housing assembly removed, inspect attraction
sleeve(s) and inside of enclosing tube for excessive corrosion
or solids buildup, which could restrict movement, prevent-
ing sleeve(s) from reaching field of switch magnet(s).
10.If differential has been changed in the field by reposition-
ing the lower jam nuts on the float stem, check tightness
and position of the jam nuts.
11.Check float to be certain it is buoyant in the liquid (float
chamber or vessel must have adequate liquid level). If float
is determined to be filled with liquid, or it is collapsed, it
must be replaced immediately.
Caution:
Do not attempt to repair a float. See
Section 5.3,
Replacement Parts
.
If all components in the control are in operating condition,
the trouble must be located external to the control. Repeat
inspection of external conditions previously described.
NOTE: If difficulties are encountered which cannot be identified,
consult the factory or your local representative for assistance.
A complete description of the trouble should be provided
along with information concerning your piping and mounting
arrangement, plus a description of your operating sequence.
Sketches or photographs showing the installation are also
beneficial.
When communicating about your control, be certain to
always specify the complete Model and Serial numbers.
4.4
What To Avoid
1. Never leave switch housing cover removed from the con-
trol longer than necessary to make routine inspections.
2. Never place a jumper wire across terminals to “cut-out”
the control. If a “jumper” is necessary for test purposes, be
certain it is removed before placing control into service.
3. Never attempt to make adjustments or replace switches
without reading instructions carefully. Certain adjustments
provided for in level controls should not be attempted in
the field. When in doubt, consult the factory or your local
representative.
