Problems Filling A Vehicle - Compac CNG Service Manual

Troubleshooting

Problems Filling a Vehicle

Problem
The dispenser is under filling
the vehicle
The dispenser stops filling the
vehicle after approximately 1kg
of gas has been dispensed
The dispenser is over filling the
vehicle
The dispenser is slow filling the
vehicle.
The preset display is flashing
after a fill.
Gas flows but does not read up
on the display.
Compac Industries Ltd.
Likely Cause(s)
The medium or high bank solenoid is
not opening.
The storage pressure in the cascades
service station pressure banks is
lower than 200 bar, causing the
dispenser to receive less gas than it
should.
The filters are blocked.
Water in the gas mains has caused
freezing, blocking the pipes.
Fast fill or temperature compensation
variables are incorrectly set
The regulator pressure is set too low.
The over pressure switch is faulty
The over pressure switch link has
come loose in J12
The regulator pressure is set too
high.
The regulator seal is worn out.
Fast fill or temperature compensation
variables are incorrectly set
Moisture in the gas mains has caused
freezing in one or more of the valves.
(This often occurs when water has
not been cleared out of the gas pipes
after testing.)
The solenoid has not closed and the
preset amount has been exceeded.
The preset display will
stop flashing when the next fill is
started.
The C4000 needs to be reset
Solenoid valves are not closing at the
end of a fill when the dispenser stops
metering because of dirt and/or water
contamination.
The meter is faulty and has stopped
Page 77
Problems Filling a Vehicle
Recommended Action
 See Solenoid Problem
section
 This is not a dispenser fault.
 Remove and replace the coalescing filters.
 Pour hot water on the frozen part of the
dispenser.
 Install a drier into the gas main.
 Check pressure transducers are calibrated
and all parameters are correct
 Replace transducers if they cannot be
calibrated
 Adjust the regulator set pressure Check the
Setting and Sealing of the Regulator (see
page 43)
 Check the End of sale indicator to confirm
there is a problem with the over pressure
switch.
 Check the wiring to the switch and switch
operation. Replace switch if no fault is found
in the wiring.
 Check the End of sale indicator to confirm
there is a problem with the over pressure
switch.
 Check the link in J12 is still in place and the
contacts are clean.
 Adjust the Regulator set pressure Check the
Setting and Sealing of the Regulator (see
page 43)
 Clean the regulator and replace the valve
seals (see page 52).
 Check pressure transducers are calibrated
and all parameters are correct
 Replace transducers if they cannot be
calibrated
 Pour boiling water onto the pipework where
the freezing has occurred until the ice has
thawed and the gas can flow.
 Contact your gas supplier
See Solenoid Problem

section
Re-power dispenser.

 Clean the solenoid and replace the valve
seals.
 Replace the meter (see page 65).
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Troubleshooting
Troubleshooting