Flow Measurement Controls - Graco Aerobotix RC50 Instructions Manual

3. Allow the day tank charge pressure to bleed to 5 psi
(0.034 MPa, 0.34 bar).
4. Close the day tank manual vent valve (MB).
5. Open day tank incoming air valve (MK).
6. Adjust pressure regulator (MC) fully clockwise.
7. Set day tank pressure by turning pressure regulator.
See the table at the beginning of the Settings sec-
tion on page 45 for recommended setting.
8. Adjust the pressure regulator counter-clockwise
until it just starts to exhaust.
9. From this point, adjust the pressure regulator clock-
wise one half-turn.
10. Lock valve knob in place.

Flow Measurement Controls

Adjusting Flowrate
.
Ensure the chemical specific gravities are accurate
and calibrate the flowrate accuracy before adjusting
the flowrate. See Calibrating Machine-Calculated
Mass Flow on page 50.
With Variable Frequency Drive and with Flow Meters
If a Variable Frequency Drive is installed then the Flow
Control screen will be available. This screen can used to
automatically adjust metering pump motor rpm so that
the flow rate remains constant.
1. Turn on MixHead, MixHead Hydraulic Motor, and
Metering Pump Motors.
2. Select calibrate mode.
3. Navigate to the flow control screen.
4. Select "Automatic" from the Flow Control screen to
select Automatic mode.
5. Type in the desired grams per second and ratio.
The speed of each metering pump motor speed will
continually adjust to achieve the input flowrate and
ratio.
313813A
6. If necessary, balance the chemical line pressures by
slowly adjusting each orifice on the MixHead with a
hex key until the pressure remains constant for at
least five seconds.
Without Variable Frequency Drive and with Flow
Meters
It is recommended that two people be used to perform
this procedure most efficiently. To perform this proce-
dure access to the pump turn-dial and the HMI will be
needed.
1. With one person standing at the HMI and the other
at the metering pump turn dial, put the machine in
calibrate mode.
2. Navigate to the Status screen to view the flowrate.
3. Turn the metering pump dial for each chemical until
the desired flowrate is reached.
With VFD and without Flow Meters
This procedure will give a good relation of motor speed
to flow rate, but will not be accurate if the pressures vary
during the test or during use. Make sure the material
pump dial is set to maximum flow by turning all the way
clockwise.
1. Using calibrate mode, set the metering pump motor
to maximum RPM and adjust chemical line pressure
to your desired operating pressure.
2. Catching the dispensed material using a
pre-weighed bucket, execute an automatic shot of
exactly 10 seconds.
3. Weigh the full bucket and subtract the empty bucket
weight to find the dispensed material weight.
4. Divide the dispensed material weight by ten to find
the flowrate in grams per second.
5. Repeat with lowest RPM and with the same pres-
sure as with the first test.
6. Graph the results showing the relationship of flow-
rate versus metering pump dial position.
Without VFD and without Flow Meters
Without a Variable Frequency Drive, the metering pump
motors will always spin at the same rpm. To adjust the
flowrate, use the pump turn dial. The following steps
detail the steps needed to create a chart for flowrate at
each pump turn-dial location.
Settings
49