18
YT-3400/3450 series
5. Adjustments
5.1
Limit Switch Adjustment
1. HIGH variable resistor adjusts the sensing point of valve end-point. In case of Direct
Action type, it will sense 4mA point, and for Reverse Action type, 20mA of input signal
will be its sensing point. Upon sensing, red LED will be lighted.
2. LOW variable resistor adjusts the sensing point of valve zero-point. In case of Direct
Action type, it will send 20mA point, and for Reverse Action type, 4mA of input signal will
be its sensing point. Upon sensing, red LED will be lighted.
3. If V+ and COM terminals are connected, electric current can be used on limit switch. It
can light up control room’s lamp or make alarm sound.
4. If V- and COM terminals are connected, electric voltage can be used on limit switch. It
can receive signal from a computer.
5. LS-ACTION dip switch enable to switch
the action between direct or reverse
action.
6. By adjusting variable resistor, limit switch
operation range can be set. If it is turn
clockwise, range will be widen; if turned
in counter-clockwise, range will be
shortened. As range adjusts, red LED
light will indicate the completion of the
adjustment.
5.2
Variable Orifice Adjustment
Hunting can be occurred when the actuator’s volume is too small. In order to prevent
hunting, orifice can be adjusted. By adjusting the orifice, the flow rate of the supply
pressure to actuator can be adjusted. Please use (-) driver to adjust the orifice.
Fig. 10:
Variable orifice adjustment
Clockwise turn:
reducing the flow rate
