15
Rotary Transmitter 4-20 mA Calibration Procedure
1. Mount the rotary transmitter to the actuator. Set limit
switches if supplied per instructions provided with unit.
2. Connect a Loop Power source to terminal points
1 & 2. The multi-meter (set for mA readings) must be
connected in series with the terminal one (refer to unit
wiring diagram for the standard setup procedure)
3. Stroke the valve to fully clockwise extreme.
4. Depress the main shaft gear disengaging it from its
locking position, take extreme care Not to turn the
main shaft gear, in order to maintain proper switch
settings.
5. With main shaft gear depressed turn the transmitter
gear to the fully counterclockwise position, and
not the reading (mA) of transmitter. Next, turn the
transmitter gear clockwise until the transmitter
changes no more than 0.5 mA from previous reading.
Renegage gears (if equipped with mechanicals
witches, depress switch plunger to allow gear to
engage).
6. Turn the clockwise mA adjustment screw to adjust the
transmitter reading to the desired output for this valve
position (typically this is 4 mA or 20 mA).
7. Stroke the valve to the fully counter-clockwise
extreme.
8. Turn the counter-clockwise mA adjustment screw to
adjust the transmitter reading to the desired output for
this valve position (opposite of step 6).
9. Stroke the valve between the full clockwise and
counter-clockwise positions checking and readjusting
the (mA) output as necessary.
Figure 20 -
Components of Rotary Transmitter or Calibration Procedure
Main Shift Gear
Transmitter Gear
Adjustment Screw 20mA
for close on increasing
Clockwise mA Adjustment
Screw 4 mA for close on
increasing
