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PB_VA-7700_Electricl Valve Actuators_02 2011
Auto-calibration■procedure■for■freely■defined■
control■signal■ranges■
Non standard control signals for example 2…8 VDC are applied
by setting the DIP switches 3 and 4
(see paragraph "DIP switch
settings")
.
It is recommended to set the actuator to the desired control-signal
type and action before fitting to valve
(see paragraph "DIP switch
settings").
Power must be connected before the auto-calibration cycle can
be started. It is recommended that the signal span is always
set superior or equal to 3V or 6 mA in order to keep acceptable
proportional characteristics.
Procedure:■(Actuator■is■mounted■on■valve)
• Verify that with the stem fully retracted, there is a minimum
distance of 1 mm between the top of the actuator stem nut and
the stem guide bush in the actuator motor housing base plate.
If necessary correct the distance by adjusting the actuator /
valve stem connection.
• The auto calibration cycle is started by pushing both calibration
buttons, on the pcb, simultaneously for at least 5 seconds.
The actuator will then make a full cycle to detect the stem
extended and retracted limits.
• Apply one of the control signal values
and■confirm■by■
pressing■one■of■the■two■calibration■buttons■for■2■seconds■
(the■5■LED■will■illuminate■for■5■sec■to■confirm■the■setting)
.
Now apply the second control signal value and again
confirm■
by■pressing■one■of■the■two■calibration■buttons■for■2■
seconds■(the■5■LED■will■illuminate■for■5■sec■to■confirm■the■
setting).
• Both the minimum and the maximum control signal values are
stored in the memory of the actuator.
• When the auto calibration cycle is completed the LED
stop flashing, the actuator stem moves to the position that
corresponds to the control signal and the five LED indicate the
stem position.
• When the control signal changes the actuator stem moves to
the new position this is indicated by one flashing LED. The LED
stops flashing when the position corresponding to the control
signal has been reached.
Position■feedback
The position feedback signal is for monitoring the actuator stroke
position. It feeds information internally to the positioner and a
0-10 VDC signal can supply an external supervisory system.
Electrical■manual■override
To select electrical manual override DIP switch 7 must be
switched to “on” (right hand position;
see paragraph "DIP
switch settings")
. The actuator stem can now be driven via the
calibration buttons. The upper button retracts the stem and the
lower button extends the stem. The stem remains in the position
at which the button is released. Switch DIP switch 7 to “off” to
return to automatic drive. The five LED indicate the stem position.
Mechanical■manual■override
To select manual override turn the override knob from “AUT” to
“MAN”, the hand wheel is then engaged and power disconnected
internally. Turning the hand wheel clockwise extends the stem
and anti-clockwise retracts the stem. Turning the override knob to
AUT disengages the hand wheel and reconnects the power.
WARNING:■The■auxiliary■switches■(terminals■
10,■11,■and■12)■can■be■used■to■indicate■manual■
override■or■automatic■mode.
Calibration buttons
> 5 sec
During auto-calibration cycle all five
status indication LED flash simultaneusly