PPCH-G™ OPERATION AND MAINTENANCE MANUAL
© 2007 DH Instruments, a Fluke Company
Page 134
OPERATION
Poor pressure control is usually caused by invalid control parameters, excessive leaks and restrictions in
the test system or other set up problems. These problems should be identified and eliminated before
resorting to use of the configuration function (see Section 6).
The VALVE CONFIG routine will cause PPCH-G to set pressure of 95% of the controller’s maximum
pressure. Be sure that any fittings or devices connected to the PPCH-G test port can safely be exposed to
this pressure prior to running the routine.
To prepare to run the VALVE CONFIG routine:
Set the PPCH-G range to the default range of the internal, high Q-RPT or utility sensor (see
Section 3.3.1).
Plug the PPCH-G
TEST
port. Do not connect any external volume.
Assure the PPCH-G is leak free (see Section 3.3.9 for leak check).
Vent the PPCH-G and wait at least 3 minutes.
To access the VALVE CONFIG function press
[SPECIAL]
,
<7internal>
,
<1config>
,
<2valves>
. Select
<2factory>
to cause PPCH-G to load original factory valve opening point tables. This feature can be
useful to return to standard conditions if a faulty VALVE CONFIG routine has been activated or the
current configuration is no longer valid.
Select
<1run>
to cause the VALVE CONFIG routine to execute. This display is:
This display warns the user that pressure will increase to roughly
95 % of the PPCH-G maximum range or of the current supply
pressure, whichever is lower. Press
[ENT]
to continue.
CAUTION: Will set up
to 70 MPa g
<Running valve config>
flashes in the lower right corner of the display. PPCH-G sets pressures and
measures valve opening points. The routine is takes up to 40 minutes to complete and includes periods of
several minutes of inactivity. When the routine is complete, the user is asked whether or not to save the new
configuration. If the VALVE CONFIG function ran completely and without incident, select
<1yes>
. Select
<2no>
to return to the MAIN RUN screen with no change to the valve opening point tables.
The effect of the CONFIG function can be eliminated and valve control coefficients returned to factory
defaults by pressing [SPECIAL], <7Internal>, <1Config>, <2valves>, <2factory>.
5.7
OVERHAUL
If calibration of the reference pressure transducers (Q-RPT) is included as part of the overhaul
procedure, the calibration procedure should be performed last.
Any or all of the following items may be included as part of a system maintenance overhaul:
•
Clean front panel.
•
Clean threads of rear panel fittings. Check for damage and replace, if necessary.
•
Check that electronic module rear panel cooling fan (top rear) operates when PPCH-G is ON.
