Electronics AC - Manual (Page 4)

4
a. SETPOINT (1-9) - To set the desired motor current, turn the setpoint knob and push dis-
play switch to the right to read desired amperage in the digital display. This will show the
setpoint for either local or remote modes of operation. Release the display switch and the
actual motor current will again be displayed. The setpoint may be adjusted during use.
Pushing the display switch to the right is optional and not necessary while changing the
setpoint during shot flow.
b. ENABLE (1-2) - The AC controller can be automatically activated by a remote enable sig-
nal when the mode switch (1-11) is in the “READY” position. The mode switch can be
placed in the “off” position, to inhibit automatic operation or it can be placed in the “on” po-
sition for manual operation.
c. ALARM (1-5) - The alarm bandwidth is adjustable from 0 to 50% of full-scale and is fac-
tory set at 10%. The alarm circuit is activated when the servo is "on" and the control is en-
abled. When the control is enabled, the "ENABLE" LED (1-2), on the front panel, will be
lighted. The midpoint of the alarm band automatically follows the setpoint setting. The
servo switch (2-11) must be on (up) for the alarms to function.
d. ALARM BAND (2-7) - The flow setpoint is also the alarm midpoint. The alarm bandwidth,
usually set at 5%, will track the setpoint . For example: a setpoint of 30A will have alarms
set at 25 and 35A. Moving the setpoint to 45A will cause the alarms to move to 40 and
50A.
e. ALARM DELAY (2-6) - When the control is enabled and in servo mode, the "high" (1-5) or
"low" (1-6) alarm light will come on if motor current is above or below the alarm limits. An
adjustable timer, labeled "ALARM DELAY” (2-6) which is adjustable from 0 - 10 seconds,
will start each time the "high" or "low" light comes on. If the fault lasts longer than the timer
setting, the high (or low) light will get brighter and the high (or low) alarm relay contact will
transfer and latch. The alarm will stay on after the “Enable” signal is removed until the
alarm is reset.
f. ALARM RESET - Activating the alarm-reset circuit (115VAC applied to Terminal #14) will
cancel the alarm relay and the alarm "high" or "low" LED's will go off. Continuous applica-
tion of the reset signal will disable or inhibit the alarm output signal. The alarms are auto-
matically reset upon receipt of each new "Enable" command and therefore using the man-
ual alarm reset function is not necessary.
g. REMOTE MODE (1-6) - A remote setpoint command may be used in place of the front
panel setpoint knob. To use this feature, the setpoint local/remote switch (2-12) must be
down in the “REMOTE” mode. A yellow LED (1-8) on the front panel indicates operation in
the remote mode. Apply a 0 - 10Vdc analog signal to the remote input, Terminal #10. A
0Vdc signal will correspond to 0% motor current command; and 10Vdc signal will corre-
spond to 100% motor current. To verify the setpoint command, push and hold the display
switch to the right. The remote command may come from a remote pot or any 0 – 10Vdc
4. OPERATION
Operation consists of controlling motor current by modulating the shot flow rate through the
MagnaValve and transmitting an alarm signal when motor current is above or below the de-
sired flow range (amperage). The servo loop controls output voltage for the MagnaValve by
comparing the setpoint command with the actual motor amps