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308783
Alarm Troubleshooting
Overdose A or Overdose B (continued)
Checking for Pressure Pulsations
1.
Close all the manifold valves.
2.
Turn on the circulating pumps and all the booth
equipment (such as fans and conveyors).
3.
Check to see if the ProMix is reading any fluid
flow.
4.
If the ProMix shows there is fluid flow and there
are no leaks from the gun or any other packings or
fittings, the flow meters are probably being af-
fected by pressure pulsations.
5.
Close the fluid shut-off valve between the fluid
supply system and the flow meter. The flow indica-
tion should stop.
6.
If necessary, install pressure regulators or a surge
tank on the fluid inlets to the ProMix, to reduce the
fluid supply pressure. Contact Graco for informa-
tion on fluid pressure regulators.
Checking the Actuation of the Valves
See page 28.
Idle Time Exceeded
This alarm will occur if the operator switch has been
turned to mix and the time elapsed since the ProMix
control has received a flow meter pulse exceeds the
idle time entered during setup.
NOTE:
If the Pot Life Time is set at 15 minutes and the
Idle Time is set at 12 minutes and the system is in mix
mode but not spraying, the Idle Time Alarm will occur
before the Pot Life Alarm, giving the operator time to
spray or move material through the system so a full
purge is not necessary.
Common Causes for an Idle Time Alarm
Operator switch turned to mix for too long when no
fluid is being dispensed.
If the gun air is being used when the alarm occurs,
the air flow switch and a flow meter have failed.
If spraying airless or air is supplied to gun by other
means than the ProMix unit and the alarm occurs,
the flow meter has failed.
Checking for an Air Flow Switch Failure
If the operator switch was turned to mix for too long
when no fluid was being dispensed, trigger the gun to
turn on the gun air to clear the alarm. If the alarm does
not clear, the air flow switch has failed and should be
replaced.
Checking for a Flow Meter or Cable Failure
Follow the Ratio Check procedure on page 25. If the
meter or cable are failing, there will be a large differ-
ence between the amount of fluid dispensed and the
flow meter volume displayed by the control.
Pot Life Exceeded
CAUTION
The ProMix pot life timer will not function when the
ProMix is used with multiple guns. To avoid having
mixed material set in the equipment, carefully moni-
tor the pot life by some other means.
This alarm will occur if the time the mixed material has
been in the lines exceeds the pot life time that was
entered during setup.
A dose of catalyst (or a complete cycle) is needed to
start the pot life timer. The pot life time resets when-
ever the specified amount of material has moved
through the system.
The alarm becomes inactive if the system has been
purged and no new material has been mixed since that
purge.
To Remove the Alarm
Clear the alarm by turning the operator switch to
purge. The system will purge until the preset purge
time is complete. Refer to page 22.
