Raven AccuFlow, Installation & Operation Manual

Page: 49 / 90

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Manual No. 016-0171-496 Rev. C 45
AccuFlow HP™ Calibration and Operation
Adjusting the Valve Cal
Refer to the Raven console Installation and Operation Manual for instructions on calculating or adjusting the
valve cal.
Note:
The valve cal may need to be adjusted to obtain desired results, particularly in applications using
low flow rates.
Adjusting the Rate Cal
Enter the target rate in actual pounds [kilograms] of nitrogen (N) per acre [hectare].
Programming Boost Pump Control
Set up boost pump pressure control (single product node) as product 2 in “Spinner RPM” mode. Enter the
following calibration values for the boost pump control product number.
•
Meter cal - 9999
•
Valve cal - 31
•
PWM frequency - 122
•
PWM low offset - 70
•
PWM preset - 70 (provides soft star for the boost pump)
•
PWM high offset - 208
•
Rate Cal (target rate): 40 - 80 PSI [275 - 550 kPa]
•
Rate bump - 5 PSI [34 kPa]
Note:
For best results, set the boost pump target rate 5 to 10 PSI [34 to 68 kPa] above the static
pressure. If the boost pump pressure (rate cal) is set too high, excess vapor will form in the supply
lines. If vapor builds up in the supply lines, the boost pump may become vapor locked which
results in no pressure boost.
Do not enter the rate cal or target rate in the pressure cal field on the control console. The
pressure cal value should only be used to calibrate the AccuFlow system pressure transducer
installed at the gauge assembly. Refer to the Charging the AccuFlow™ System and Calibrating
the Pressure Transducer section on page 46 to configure the pressure transducer.
CAUTION
To avoid damage to boost pump seals, do not
run the boost pump dry. Be sure to shutdown
the boost pump when no anhydrous ammonia
is flowing through the pump or when the nurse
tank is empty.