4
TROUBLESHOOTING
TROUBLESHOOTING
In-service problems are unlikely, but the following paragraphs
suggest ways to verify any problems that might arise:
1.
Vacuum Switch Leaks
If a leak is suspected, isolate the Vacuum Switch from the
rest of the system. Connect the switch and a calibrated
pressure gauge downstream from a pressure source and
shutoff valve. Apply normal system pressure, isolate the
gauge and Vacuum 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.
If a leak is verified, return the unit for repair. Contact ITT
directly, or your local sales representative or distributor (see
www.neodyn.com
for a contact list).
2.
Failure to Switch
If application of vacuum 10% greater than the adjusted set
point fails to produce actuation, first check for contamination
in the process connection, and verify that the expected
pressure is reaching the sensing diaphragm or piston.
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, or the switch
element has moved away from the position where it was
synchronized with the snap action. Return the unit for repair.