100P Enclosure 7 Adjustable Pressure Switch
Page 10
CHAPTER
4
TROUBLESHOOTING
In-service problems are unlikely, but the following paragraphs
suggest ways to verify any problems that might arise:
1.
Leaks
If a leak is suspected, connect the pressure switch and a
calibrated pressure gauge downstream from a pressure source
and shutoff valve. Apply normal system pressure, isolate the
gauge and Pressure Switch from the pressure source with the
shutoff valve for at least one minute, and check for leaks as
evidenced by a drop in the gauge reading.
Leaks may be repaired by replacing the sensing diaphragm
and O-ring (wetted materials 1 and 4 only). Contact ITT for
replacement parts and instructions, or return the unit to ITT
for this repair.
2.
Failure to Switch
If application of pressure 10% greater than the adjusted
setpoint fails to produce actuation, first check for
contamination in the pressure line, and verify that pressure is
reaching the sensing diaphragm. If the Belleville spring can
be heard to audibly snap, but an ohmmeter indicates no
electrical switching, the cause is probably stuck or burned
switch contacts, and the switch element needs to be replaced.
Return the unit to ITT for this repair.
