Graco PrecisionMix ii, Instructions And Parts List

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10-10
Troubleshooting
Alarm Troubleshooting
Overdose A, B, or C (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 PrecisionMix II 3K is reading
any fluid flow.
4. If the PrecisionMix II 3K shows there is fluid flow
and there are no leaks from the gun or any other
packings or fittings, the meters are probably being
affected by pressure pulsations.
5. Close the fluid shut-off valve between the fluid
supply system and the meter. The flow indication
should stop.
6. If necessary, install pressure regulators or a surge
tank on the fluid inlets to the PrecisionMix II 3K to
reduce the fluid supply pressure. Contact your
Graco distributor for information on fluid pressure
regulators.
Checking the Actuation of the Valves
See page 10–8.
Flow Rate Alarms for a System without
Flow Control
Flow Too Low
Alarm output will be on Output #2 of Module #2.
The PrecisionMix II 3K is dispensing a lower fluid flow
rate than pre-selected in the Recipe Setup screens.
Common Causes for a Flow Too Low Alarm
Low fluid pressures from the fluid supply system
The buildup of cured paint in the fluid components
downstream of the PrecisionMix II 3K
The dispense valve knobs are turned too far in
Flow Too High
Alarm output will be on Output #3 of Module #2.
The PrecisionMix II 3K is dispensing a higher fluid flow
rate than pre-selected in the Recipe Setup screens.
Flow Rate Alarms for a System with
Flow Control
Gun #1 High/Low Flow
High/Low flow alarm output will be on Output #2 of
Module #2.
Gun #2 High/Low Flow
High/Low flow alarm output will be on Output #3 of
Module #2.
The Gun #1 and Gun #2 alarms will occur when the
fluid flow rate out of the gun goes above or below the
alarm tolerance setting for three seconds.
Example: If a gun flow rate setpoint of 500 cc/minute
and a tolerance of 10% was entered, the Gun High
Flow alarm would occur if the actual flow rate was
more than 550 cc/minute for three full seconds. A Gun
Low Flow alarm would occur if the actual flow rate was
less than 450 cc/minute for three full seconds.
Pot Life Exceeded
Alarm output for Gun #1 will be on Output #4 of
Module #2.
This alarm will occur if the mixed material is in the lines
for a longer period of time than the pot life time value
that was entered during setup.
For example: If a pot life value of 30 minutes and a
volume of 600 cc was entered, the Pot Life Exceeded
alarm would occur if over a 30 minute period, 600 cc of
fluid was not dispensed.
The alarm becomes inactive if the system has been
purged and no new material has been mixed since that
purge.
To Remove the Alarm
You have two minutes to move fresh mixed material
out to the gun. If this cannot be done, AUTO DUMP
will activate if that feature has been selected. Other-
wise, a full purge cycle will be required to clear the
alarm.