PPCH-G™ OPERATION AND MAINTENANCE MANUAL
© 2007 DH Instruments, a Fluke Company
Page 142
SYMPTOM
PROBABLE CAUSE
SOLUTION
The external (RPM4) Q-RPT is not initialized.
Check that the external RPM4 is connected
and initialized properly. 2.3.7.1, 3.3.5
The Q-RPT range does not cover the desired
AutoRange.
Check that Q-RPT default range is high
enough to cover the AutoRange. Table 1
AutoRange is not selecting the
desired Q-RPT for the specified
range.
The measurement mode specified by
AutoRange is absolute and absolute mode is
OFF for the desired Q-RPT.
Check that absolute/ mode is ON for the
Q-RPT. 5.2.5
There is a
<C>
to the right of the
<D>
,
<d>
,
<S>
,
<M>
or
<R>
control mode character on the
bottom line of the display and it
won’t go away.
Custom control parameters have been set.
Reset control parameters to default by
selecting a control mode using the
CONTROL function. 3.4.6.2
Pressure display is flashing and
beeper is sounding intermittently.
Current upper limit of active range has been
exceeded.
Correct overpressure condition. Change
UL and/or active range if needed. 3.4.4,
3.4.4.1, 3.3.1
Pressure display is flashing, no
beeper is sounding and direct
pressure control keys are inactive.
PPCH-G and/or external RPM4 has been
over-pressured.
Correct the overpressure condition and
cycle power ON and OFF. 3.4.4.1
Display is <Check Xaa aaa RPT,
wdog: nnnnn uuuum> and
pressure control is aborted.
PPCH-G internal watchdog measurement
system has detected that active external Q-
RPT does not appear to be connected as its
pressure is not changing as expected when
PPCH-G controls the pressure.
Check that external RPM4 Q-RPT is
connected properly to PPCH-G
TEST
port.
Cycle PPCH-G power and retry. 2.3.7.1
A
Ready
(green) indication is
never achieved or is only
momentary.
Control parameter settings are too tight
and/or existing conditions will not allow
Ready
to be achieved.
Adjust control parameters or correct other
conditions. 3.4.6.1, 3.2.3, 3.2.2
Dynamic control is being used and
it takes too long to get a
Ready
condition or the
Ready
condition
is not maintained long enough.
System connected to PPCH-G
TEST
port
has leaks or has a volume that is too large.
Correct leaks to extent possible. Try using
“hi volume” dynamic pressure control
mode. 3.4.6.2, 3.2.2.2
Cannot select absolute
measurement mode.
Absolute measurement mode has been
turned OFF in the calibration function.
Turn absolute mode ON. 5.2.5
Will not accept pressure command.
Target exceeds UL and/or current range.
Check UL, range and measurement mode.
3.4.4, 3.3.1, 3.3.3
The drive air pressure supply is not adequate
to open the high pressure supply isolation
valve.
Increase drive air pressure supply. 2.3.5
The is little or no high pressure pressure
supply connected to the
SUPPLY
port.
Assure adequate pressure supply to
SUPPLY
port. 5.8, 3.5.7.3
There is a very large leak in the test system
or
TEST
port is not connected.
Correct leak. 2.3.7, 3.3.9
Will not generate pressure.
Very large test volume.
Operation is normal. Wait for pressure to
increase.
Poor pressure control
characterized by erratic rates
during pressure slewing or sudden
pressure over and/or undershoot
at the set point.
High pressure gas supply connected to
SUPPLY
port is not sufficiently stable.
Correct high pressure supply source. May
require higher flow or a larger accumulator
on the supply. 2.3.6
Poor pressure control characterized
by control interrupting near the
target pressure.
Control mode is set to static mode rather
than dynamic mode.
Set control mode to dynamic. 3.2.2,
3.4.6.2
Poor pressure control characterized
by pressure never stopping.
Control mode is set to monotonic or ramp
mode rather than dynamic or static mode.
Set control mode to dynamic or static.
3.2.2, 3.4.6.2
[ENT]
from main run screen doesn’t
result in a target pressure entry
screen.
Control mode is set to ramp mode rather
than dynamic, static or monotonic.
Set control mode to desired mode. 3.2.2,
3.4.6.2
Poor pressure control characterized
by excessive overshooting/
undershooting and/or “hunting”
d t
t i d
i
t l
There is a restriction in the test connection
between the PPCH-G and the test or the
PPCH-G, the RPM4 and the test.
Remove the restriction to allow free flow
between the PPCH-G, the RPM4 (if
present) and the test. 2.3.7
