9
Adjustment
- Span
1. After setting zero, supply 20mA or 4mA of signal.
Check the actuator’s stroke. If the stroke is too low,
adjust the span towards the (+) direction.
If the stroke point is too high, adjust the span towards
the (-) direction. (Figure 18)
2. Changing span points affects the zero point setting,
so the zero setting must be set again. After setting
zero point, confirm the span point. This step must be
repeated until both points are properly set.
3. After setting is completed, tighten lock screw.
Adjustment
- A/M Switch (Auto/Manual)
1. A/M switch adjusts the valve operation to automatic
or manual.
2. When produced, YT-
1000L is set at “A(Automatic)”.
If user prefers the positioner setting as “M(Manual)”,
the setting can be changed by turning the switch coun-
ter-clockwise. (Figure 19)
3. If it is set as “M(Manual)”, the air pressure will be
supplied to the actuator directly. Always set back to
“A(Automatic)” after setting change.
4. If OUT2 in single acting actuator or double acting
actuator is used, the A/M switch will not operate.
Adjustment
- Seat Adjuster
1. Seat adjustment is set according to the customers
request before the positioner is delivered. Please do
not adjust the seat adjuster.
2. Seat adjuster is always used for double acting
actuators and adjusted when the pressure balance
point must be changed. Please do not touch the seat
adjuster, because it can affect the positioner’s
performance.
Adjustment
- Orifice
1. If the size of the actuator is too small relative to the
flow rate, the positioner can have hunting. In order to
avoid hunting, orifice can be used. There are three
types of orifice.
CVS Controls Ltd.
Product Manual: CVS Rack & Pinion Actuator
CVS Controls Ltd.
Process Management
And Instrumentation
Lock Screw
Lock Screw
Seat Adjuster
Auto Manual Switch
Output
Pressure
Output
Pressure
Output
Pressure
High Pressure Balance
(0.9~1.0Ps) - Normal
Med. Pressure Balance
(0.5Ps) - Normal
Low Pressure Balance
(0.4~0.5Ps) - Normal
Balanced Point
Balanced Point
Balanced Point
Input Pressure
Ps=Supply Pressure
