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22 311594Z
Pressure Sensor Calibration Information
(non-ACS systems)
NOTE: To calibrate the transducer in systems using the
Graco ACS Module, see the ACS manual 3A0006.
Pressure sensor information (Pr 20.34, 20.35, and
20.36) for your system must be keyed into the Vari-
able Frequency Drive before system start-up.
To prevent accidental change of pressure sensor cali-
bration parameters, they are locked by Pr 20.16. To
enter calibration parameters, perform the following
steps:
a. Set Pr 20.16 to 777, to unlock pressure sensor
parameters.
b. Enter calibration parameters Pr 20.34, 20.35,
and 20.36.
c. Set Pr 20.16 to 0 to lock pressure sensor
parameters.
Calibration Parameters from the label:
Pr 20.34 – Zero Calibration
Pr 20.35 – Calibration Pressure
Pr 20.36 – High Calibration
Pressure Transducer Calibration
Procedure (non-ACS systems)
E-Flo pressure sensor must be calibrated against an
instrument grade High Precision Pressure Transducer,
which should be installed near the E-Flo pressure sen-
sor.
1. Ensure that the High Precision Pressure Transducer
calibration is up to date.
2. Set Pr 20.16 to 777, to unlock pressure sensor
parameters.
3. Calibrate Low Pressure Point as follows:
a. Ensure that system is not pressurized. Calibra-
tion instrument pressure reading should be 0
psi.
b. Use Keypad to navigate to Pr 20.33; monitor its
reading for 5 – 10 seconds to determine its
average value. Make a record of it.
c. Navigate to Pr 20.34 and enter the recorded
average value of Pr 20.33.
4. Calibrate the High Pressure Point as follows:
a. Pressurize the system to 250 – 275 psi.
b. Keep the system pressurized and ensure that
pressure does not fluctuate.
c. Take a pressure reading from the calibration
instrument and make a record of it.
d. Navigate to Pr 20.35 and enter the recorded
system pressure.
e. Navigate to Pr 20.33; monitor its reading for
5-10 seconds to determine its average value.
Make a record of it.
f. Navigate to Pr 20.36 and enter the recorded
value of Pr 20.33.
5. Set Pr 20.16 to 0 to lock pressure sensor parame-
ters.
6. Verify pressure calibration.
a. Relieve system pressure.
b. Navigate to Pr 20.31 and verify that its reading
is within the range of 0-3 psi.
c. Pressurize the system to about 100 psi. Verify
that reading of Pr 20.31 is within +/- 2.5 psi of
the system pressure.
d. Pressurize system to about 250 psi. Verify that
reading of Pr 20.31 is within +/- 2.5 psi of the
system pressure.
Do not exceed pressure rating of the system! If system
is rated to a pressure lower then 250 psi, use maxi-
mum allowable rated pressure. Refer to Operation
Manual 311593.