10
8 ACE 71 en
5
OPERATING
5.1
General
Step motor controller has two modes: automatic (AUTO)
and local (MAN).
In automatic mode the control panel is disabled and step
motor is controlled by the control system. In local control
mode the step motor can be driven to both directions by
using the control panel push buttons, Fig. 14. Automatic/
local mode selection is done by AUTO/MAN push buttons.
When selecting local control mode the MAN push button
must be pressed for more than one (1) second. The lit LED
indicates that local control mode (MAN) has been selected.
Control unit receives position information from the actua-
tor's potentiometer. This position information is shown as
percentage in the panel's LCD display. Control panel has
LEDs to indicate limit switch status (open or close).
In the control panel display, 0 % indicates a closed valve
and 100 % indicates an open valve.
5.2
Keyboard functions
Arrow push buttons < or > :
Arrow push buttons are only active in local control (MAN)
mode. The valve closes with the arrow push button < and
opens with the arrow push button >. The actuator moves as
long as the button is pressed down or it reaches the limit
switch.
AUTO/MAN selection:
AUTO and MAN modes are selected with corresponding
keys.
5.3
LEDs in the control panel
AUTO/MAN (green):
LED indicates the operation mode of control unit. When
LED is lit the control unit is in manual mode.
OPEN (red):
LED is lit when the actuator is in its opening position limit.
CLOSE (red):
LED is lit when the actuator is in its closing position limit.
6
MAINTENANCE
6.1
General
NelesAce is a digital and modular device. This facilitates
maintenance. The smallest step motor movements are
impossible to distinguish from the movements of valve or
shafts without special measuring instruments. For this rea-
son the functioning of control unit/actuator/valve-combi-
nation must be evaluated from the hand wheel (108)
movements or lack of movements. The hand wheel is
attached to motor shaft.
The hand wheel's handle must
be pressed down during operation.
6.2
Calibration of the display
The output current of the actuator's position transmitter is
4 mA when the valve is closed. When the valve is fully open
the output current is 20 mA. Calibration to R/I modulator is
carried out at the factory according to these output values.
The display card has two potentiometers (R9 and R14)
which are used to calibrate display readings to equal to the
readings of current output.
Fig. 15
Control panel
Fig. 16
Calibration potentiometers in display card
X14
N1
D1
ZERO
SPAN
R14
R9
V3
S5
S7
V5
S8
S6
V4
