Electro-Pneumatic Positioner
YT-1000 / 1050 series
Product Manual
Ver. 1.30
69
7.6
Orifice Installment
If the actuator size is too small relative to the flow rate of positioner, hunting can occur. In order to avoid
hunting, the orifices can be installed in the outports of the pilot.
1)
Separate the pilot unit from the positioner.
2)
Separate the o-rings from out1 and out2 ports, and insert the orifices. Before re-assemble the o-
rings, please make sure there is no remaining dust or particles on the ports.
3)
Standard diameter of the orifice hole are 1 mm. 2 mm diameter orifice can be ordered.
Fig. 7-14: Installing orifices
7.7
Reset – Potentiometer
External damage or physical shock can dislocate potentiometer from factory setting. Potentiometer
must be re-calibrated when dislocation of the potentiometer or after cam adjustment. Please refer
below instructions and figures.
1)
Please set actuator position to 50 % of the valve stroke. Please make sure that the actuator does
not move during the re-calibration.
2)
In the junction box, Please pull out the potentiometer cable connector from potentiometer PCB. Do
not pull out with too much force as wires can be damaged.
3)
On the potentiometer cable connector, there are three holes. Out of three holes, please measure
resistance level by plugging two hole (one of right or left and one of center) using a resistance
tester. The potentiometer resistance level should be within 0 ~ 10 kΩ (Rotary positioner) and within
0 ~ 5 kΩ (Linear Positioner) during full stroke of the actuator.
4)
Using “+” screw driver, loosen potentiometer stopper bolt. Do not loosen completely.
5)
Pull out the potentiometer a little and gear of the potentiometer will be separated from main shaft
gear. This will make user to turn the gear of the potentiometer.
6)
Since current actuator position is 50% of the valve stroke, the resistance level should be measured
around 5 kΩ (4.8 ~ 5.2 kΩ) at rotary positioner and 2.5 kΩ (2.4 ~ 2.6 kΩ) at linear positioner by
turning gear of potentiometer.
7)
After the setting, assemble back the stopper and the bolt.
