Flowserve Position Transmitter User Manual

Position transmitter calibration instructions, Pt20sd

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Position Transmitter

Calibration Instructions

For use with non-UEC controls only; to use with UEC-3 controllers,
please see bulletin 440-12000, UEC-3 Operation Manual

Feedback

potentiometer

1K ohms

4mA Adjust

20mA Adjust

Power ON indicator

4-20mA +VE

4-20mA -VE

4-20mA

Output

-VE

LK2 and LK3 jumpers.

For actuator equipped

with UEC-3 or

UEC-3-MPC 24VDC

input, move jumpers

to “DC” position. For

actuators equipped

with 18VAC input, move

jumpers to “AC”

position.

+VE

Power Supply:

24VDC

4

OVDC

6

or

18VAC

4

OVAC

6

6

4

2

1

Specification

Output signal

• 4-20mA

Input potentiometer

• 1K (ohms)

Temperature rating

• -40 to +85

°

C

Linearity error

±

1% max.

Loop resistance

• 370 (ohms) max.

Power

• 18 VAC or 24 VDC

±

10% (LK2

and LK3 must be set

appropriately)

Important note

Analog inputs must not be

connected to earth ground on

+VE or -VE terminal.

Calibration procedure

1. Position the actuator to mid-travel (valve at 50% Position).
2. Disconnect the potentiometer wiring harness from the PT20SD board

and measure the resistance from each End connection to the center
connection on the potentiometer.

3. To set the potentiometer to the correct resistance reading, loosen the

setscrew that retains the spur gear on the potentiometer shaft and
rotate the shaft until a reading of 500(ohms) is acheived.

4. Tighten the setscrew and reconnect the wiring harness to the PT20SD.
5. Run the actuator fully CLOSED.
6. Calibrate ZERO position by adjusting the zero potentiometer until

a 4mA output signal is read at terminals +VE and -VE.

7. Run the actuator fully OPEN.
8. Calibrate SPAN position by adjusting the span potentiometer until

a 20mA output signal is read at terminals +VE and -VE.

9. Repeat steps 5 to 8 and fine-tune as necessary.

PT20SD

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