ARI Armaturen RI21 EN - Manual (Page 19)

Rev. 0040602000 1014 Page 2-19
Operating and installation instructions 
Electronic position indicator RI21
6.4 Zero point setting
- Observe the order of the settings: 
1. Potentiometer (refer to 6.2)

2. Type of control signal (refer to 6.3) 
3. Zero point (refer to 6.4) 
4. Slope span (refer to 6.5)
- In case of subsequent changes to a setting, the following settings must be
readjusted!
a) The voltage supply must be disconnected before carrying out any setting work.
b) Turn the valve stem with the handwheel for the min. control signal in the desired position,
e.g. 4mA or 0V, (according to the switch position SW and as shown in Fig. 11 : Effective
direction). Typically this will be the closed valve.
c) Set the input signal to the minimum required value, e.g. 4 mA or 0 V.
d) Disconnect the line separating terminal X2, X25 or X28 to the motor and let it be
separated.
e) Connect instrument corresponding to the set control signal type to terminal X16 
- Yu: voltmeter at terminal Yu and GND 
- Yi: amperemeter at terminal Yi and GND
e) Connect voltage at L and N from the 2-pin series isolating terminal, the yellow LED must
be lit.
f) Adjust the zero adjustment screw N until the minimum desired control signal value on the
instrument is shown (after 25 rotations, the slip clutch sets). 
- Increase value: turn clockwise, 
- Decrease value: turn anti-clockwise. 
E.g.: 
- Current output ............minimal value .........Yi = 0 mA or 4 mA 
- Voltage output..................minimal value ............Yu = 0V or 2V