Welch Vacuum 2028 Self-Cleaning Dry Vacuum System - Manual (Page 20)

Section 6: TROUBLESHOOTING
6.10 Vacuum Problems
Leakage, contamination and unusual out gassing are the general causes of problems associated with
poor vacuum. To operate at maximum effi ciency a system must be thoroughly clean. If the system is
completely clean and free from leaks, and unwarrantable vacuum problems still exist, the pump should
be checked. A simple criterion for checking the condition of the pump is the determination of its maximum
vacuum capability. This can be accomplished by blocking off the intake and reading the vacuum level on
the gauge (See Section 3.30).
Problem Possible Cause Solution
Mechanical Failures
Pump not working
Power off
•
Check all power connections
•
Pump under Vacuum
•
Disconnect pump from system.
•
Open vacuum control valve and Gas ballast.
Self Diagnostic Test
•
Do nothing - The pump is running a 30sec. Self
•
diagnostic test to ensure all components are
working correctly.
If problem persists, contact Welch
Technical Support*.
Pump stalled
Pump under vacuum
•
Note:
Pump Cannot Start Under Vacuum
Open vacuum control valve and gas ballast.
•
Turn-off and UNPLUG PUMP, remove top
•
housing and turn fan a few times. Replace
cover and turn on, if problem still continues
contact Welch Technical Support*. Turn pump
off, disconnect from application, restart pump
Display shows unreliable measurements
Check vacuum pressure of 2027xx
•
with external vacuum gauge, attached
to pump inlet fi tting.
If external vacuum gauge pressure is different
•
than unit’s display by more than 5 Torr, problem
is with one of three electronic parts (electronic
problems):
- Vaccum pressure display
- Pressure pickup
- Electronic board
Loose or not completely inserted wire
•
or connector
All electronic connections on electronic board
•
and vacuum display should be rechecked to
see that there is no
Multi wired pickup ribbon connection
•
at pressure pickup may have loose/
broken one of the four wires (usually
one of outside wires).
New pickup should be installed or repaired by
•
re-soldering loose wire to pressure pickup.
Electronic board could have corrupted
•
software or calibration
Faulty board should be returned to the factory
•
to exchange it for new one
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