Graco PrecisionFlo XL Instructions Manual page 122

Frequently Asked Questions
Q:
Why will my fluid control regulator not calibrate in the Pressure screen?
A:
You may not have enough fluid pressure downstream of the regulator — at least 500 psi (3.5 MPa, 34.5 bar) is
required. Try a smaller nozzle on the dispense valve.
Q:
Why will my fluid control regulator not calibrate in the Flow screen?
A:
You might not have selected a flow meter in the Config–General screen. You may not have been able to reach
the maximum flow rate you entered. To reach a higher flow rate, you can increase the feed pressure or
increase the dispense valve nozzle size.
Q:
Why will my dispense valve not operate?
A:
The valve will not dispense in Flow Mode if the flow calibration has failed. Calibrate the flow rate as instructed
on page 1.
Q:
Does Pressure Mode use a flow meter?
A:
Running in Pressure Mode does not require a flow meter. However, without a flow meter, you cannot monitor
the job volume limits or log the job volumes. The number of flow meters installed must be selected on the
Config–General screen.
Q:
Why is the psi/volt setting important?
A:
The psi/volt setting is important if you are only running in the Pressure Mode. This is what sets the relationship
between the robot analog signal and the desired pressure. For example, a psi/volt setting of 200 will produce
1000 psi (7 MPa, 70 bar) outlet pressure at an analog signal of 5 volts. The psi/volt setting is calculated and
set automatically if you have a flow meter installed and do a flow calibration to your maximum desired flow rate.
The psi/volt setting is 10% of the Flow Calibration maximum pressure.
Q:
Why are the digital speed settings important if I am running off of a 0–10 volt analog signal
from a robot?
A:
1.) Low Flow Rate setting: If the analog signal drops below 1 volt, the PrecisionFlo XL control will default to
the Low Flow Rate setting. If you are working through a wide analog range, this setting could be very useful to
you.
2.) Medium Flow Rate setting: This setting affects how well the flow compensation works across the middle to
upper flow range. The Medium Flow Range percent setting should be set to your average robot analog signal.
For example: If you run between 5–8 volts, the average is 6.5 volts or a 65% setting.
3. High Flow Rate setting: This setting has no effect when you are running in the analog robot mode.
Q:
How can I verify that my I/O interface wiring is correct before loading and running the dis-
pense equipment?
A:
With the TouchScreen interface, select the Module I/O tab, or the Robot I/O tab, to view the status of all inputs
and outputs. With the EasyKey interface, check the status of LED lights on the robot I/O board, using the table
on page 106.
Q:
How do I know my flow and volume measurements are accurate?
A:
Calibrate the flow meter as instructed on page 38. This is strongly recommended as many sealants are
compressible, and the flow meter measures the fluid while it is under pressure. Calibrating the meter makes it
accurate for your fluid at ambient pressure. Periodic calibration is also important to monitor your meter for wear.
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