HELIX GRANVILLE-PHILLIPS Convectron ATM Instruction Manual page 71

Table 5-1 Failure symptoms, causes, and solutions
Symptom
Output voltage = 0 V
Pressure reading is too high.
Pressure reading is inaccurate.
Indicated pressure is different than
pressure indications from other
measurement devices.
Relay LED indicator is ON, but relay is
not functioning.
• Relay will not activate.
• Output voltage is < 0.10 V.
®
Convectron ATM Vacuum Gauge Module Instruction Manual
Possible causes
11.5 to 26.5 V power supply cable is
improperly connected or faulty.
• Conductance in connection to
vacuum chamber is inadequate.
• Plumbing to module leaks or is
contaminated.
• Chamber pressure is too high due to
leak, contamination, or pump
failure.
• Power supply or output cable is
improperly connected or faulty.
• Module is not calibrated for the
process gas that is being used.
• Module is not mounted horizontally.
• Convectron gauge or differential
pressure sensor is damaged (for
example, by reactive gas) or
contaminated.
• Temperature or mechanical
vibration is extreme.
• Process gas is a not the gas that the
user anticipated using in the system.
• Convectron gauge is defective.
Relay contacts are defective.
• A circuit board is faulty.
• Convectron gauge sensing wire is
open.
Maintenance
Solution
Repair or replace power supply cable
(see page 10).
• If conductance is inadequate,
reconnect Convectron gauge port to
vacuum chamber (see page 9).
• If plumbing leaks or is
contaminated, clean, repair or
replace plumbing.
• If pump failed, repair or replace it.
• If cable is improperly connected or
faulty, repair or replace cable (see
page 10).
• If Convectron gauge is out of
calibration, recalibrate it for the
process gas that is being used (see
page 34 or page 56).
• If module is not mounted
horizontally, re-mount it (see
page 8).
• If Convectron gauge is damaged,
replace it (see page 67).
• If Convectron gauge is
contaminated, return it to factory
(see pages 68 and 70).
• If temperature or vibration is
extreme, relocate module or
eliminate source of heat or
vibration.
• If the process gas is not what was
anticipated, calibrate Convectron
gauge for gas that is being used (see
page 34 or page 56).
• If Convectron gauge is defective,
return it to factory (see pages 68
and 70).
Make sure relay load is within
specified rating and is non-inductive
(see page 74).
Return module to factory (see page 70).
63