Electronics FC-24 - Manual (Page 4)

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D. For automatic machine cycle, push the “Mode” button (2-22) until the “Ready” LED (1-6) is
on. When a 24Vdc "Enable" signal is received the "On" LED indicator (1-7) will come on
and activate the valve output. The bar graph display (2-13) will indicate the relative signal
strength sent to the MagnaValve. Adjust the flow rate setpoint with button (1-8) and ▲or
▼ buttons to the desired flow rate. The display is usually scaled in pounds/minute, but
may be scaled in Kg/minute.
E. Display the alarm bandwidth by pushing button (1-4) and using ▲or ▼ to change the set-
tings. A typical setting is 5% of full scale.
F. Select either percent of point (PT) or percent of full scale (FS) for the alarm band by push-
ing button (2-16). Typical setting is percent of full scale (FS). The alarm bandwidth is +/-
this value and follows the set point command.
G. Adjust the alarm delay time (2-17) from 0-10 seconds. A typical setting is 5 seconds.
5.CALIBRATION
A. The MagnaValve has been factory calibrated to provide a 10 Vdc signal output at its rated
flow If a different type or size of shot is used it maybe necessary to re-calibrate the sys-
tem. The span setting can be changed at the MagnaValve or at the FC 24 controller. The
calibration change should be made at the FC 24 controller for convenience, since replace-
ment MagnaValves will have the same calibration as the original and the span setting at
the FC-24 controller can easily be displayed as described below.
B. Push the “Span” button (2-19) to display the current span setting. The factory standard
setting is 1.000 for unity gain. The range of the span function is between .750 and 1.500.
C. To check the flow accuracy, perform a catch and weigh test. Run shot through the Magna-
Valve for 1 minute and catch it in a container. Weigh the shot. Use the ▲or ▼ buttons to
increase or decrease the flow rate. Repeat the trial to confirm calibration. Keep a record of
the span setting to be used in case the FC-24 controller is replaced.
6.OPERATION
A. Operation consists of controlling the shot flow rate through the MagnaValve and transmit-
ting an alarm signal when the flow rate is above or below the desired flow range. The shot
flow rate for the MagnaValve is controlled by a servo loop that compares the setpoint com-
mand to the actual shot flow rate.
B. SETPOINT - To read the current setpoint push the “Setpoint” button (1-8). To change the
value use the ▲or ▼ buttons.
C. MODE - The FC controller has three mode settings: “Off”, “Ready” and “On” as indicated
by LEDs (1-5, 6, 7). The “Off” mode prevents any shot flow. The “On” mode will activate
the MagnaValve manually. The “Ready” mode will only activate the MagnaValve upon re-
ceipt of a 24 Vdc “Enable” signal. The “On” LED will come on upon receipt of the enable
signal and will get brighter upon expiration of the “Enable Delay”.
D. ENABLE DELAY – The “Enable Delay” feature is set by button (2-21) and is used to allow
the air pressure to stabilize prior to activating the MagnaValve output. A typical setting is 3
seconds. Without this delay the air blast system may exhibit unstable flow conditions for
15 or more seconds.
E. ALARM BANDWIDTH - The alarm bandwidth is adjustable from 0 to 50% of full scale or of
setpoint and is factory set at 5% of full scale (FS). The alarm circuit is available only when
the servo is "on" and the control is enabled. The flow set point is also the alarm mid-point.
The alarm bandwidth, usually set at 5%, will track the flow set point setting.
F. If the Alarm Mode is set for percent of full scale (FS) as indicated by LED (2-14) then, with
5% of full scale and a full scale of 20 lb/min, the alarm band is ± 1 lb/min. For a setpoint of
12 pounds/minute the alarms would be active below 11 and above 13 pounds/minute.