Graco PrecisionMix ii, Инструкция и перечень запасных частей

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10-9
Troubleshooting
Alarm Troubleshooting
Dose Time A, B, or C
When the PrecisionMix II 3K is in the MIX mode and
the air flow switch is closed, which indicates that the
gun is being triggered, the PrecisionMix II 3K is pro-
grammed to expect that the resin, catalyst, or reducer
will dispense at least ten flow meter pulses every
10–60 seconds. The 10–60 second time period is
customer settable. Refer to page 8–15. The Air Flow
Switch alarm will occur if one of the components is not
dispensed within the set time period.
Dose Time A
The PrecisionMix II 3K has not completed a dose of
Component A (resin) within a a set time period.
Dose Time B
The PrecisionMix II 3K has not completed a dose of
Component B (catalyst) within a set time period.
Dose Time C
The PrecisionMix II 3K has not completed a dose of
Component C (reducer) within a set time period.
Common Causes for an Air Flow Switch Alarm
The system is in the MIX mode and the gun is only
partially triggered, allowing air but no fluid to pass
through the gun
The fluid flow rate becomes too low
The meter or cable fails
The dispense (dose) times are set too low
If a meter or cable fails, resin, catalyst, or reducer will
flow to the gun without the flow being read through the
meter pulses. The PrecisionMix II 3K could keep the
dispense valve open indefinitely because the computer
will never see the target value being reached. This
condition could cause the operator to spray pure resin,
pure catalyst, or pure reducer onto a part.
To prevent this from happening, the computer will only
allow the Component A, B, or C valve to remain open
for the duration of the dose time. The alarm will alert
the user if the dose time is exceeded.
Checking for a Meter or Cable Failure
Manually open the catalyst, resin, or reducer dispense
valve and trigger the gun into a grounded waste con-
tainer. The counts should increase in the first Run
screen on the User Interface.
NOTE: This test will probably cause an Overdose
alarm.
Overdose A, B, or C
An Overdose alarm occurs if the fluid continues to
dispense on the one side of the manifold after the
valves have opened on the other side of the manifold.
Overdose A
The PrecisionMix II 3K has continued dispensing fluid
on the Component A (resin) side after the valve has
shifted to the Component B (catalyst) side. An alarm
will occur when the actual dose size reaches 20 cc
higher than the target value for Component A.
Overdose B
The PrecisionMix II 3K has continued dispensing fluid
on the Component B (catalyst) side after the valve has
shifted to the Component A (resin) side. An alarm will
occur when the actual dose size reaches 10 cc higher
than the target value for Component B.
Overdose C
The PrecisionMix II 3K has continued dispensing fluid
on the Component C (reducer) side after the valve has
shifted to the Component B (catalyst) side. An alarm
will occur when the actual dose size reaches 20 cc
higher than the target value for Component C.
Common causes for an Overdose Alarm are:
Valve(s) packings or needle/seat are leaking
Ratio check valve is leaking
Flow meter fluctuations caused by pressure pulsa-
tions,
Slow actuation of the resin, catalyst, or reducer
valves
Last purge solvent fill did not remove air from the
mixed material lines, causing excessive flow rate
during mixed material load process.
Continued on the next page.