Electronics MC - Manual (Page 3)

H:\MANUALS\IM0049C.DOC Installation Manual Model MC Shot Flow Controller 3 of 12
1. PRODUCT DESCRIPTION
The Model MC Shot Flow Controller will control the rate of flow of steel shot passing through a special
normally closed magnetic valve called a MagnaValve. A setpoint knob or an external 0-10 Volt dc
command signal is used to set the shot flow rate.
2. THEORY OF OPERATION
The MagnaValve is a normally closed magnetically operated valve with no moving parts. An
electromagnet coil inside of the valve is used to cancel the permanent magnet field and allow shot to
flow. The MC controller supplies the voltage to the MagnaValve and provides 0-100% regulation of
flow rate.
3. PRELIMINARY ADJUSTMENTS
(For location of adjustments see (Figure-Item) as noted.)
Maximum Output Limit:
On wheel type blast machines it is usually desirable to limit the maximum motor amps by restricting the
maximum shot flow rate to the wheel. The maximum output signal from the MC controller may be
restricted to prevent excessive flow rates that might overload the wheel motor. Remove the front panel
lower cover plate for access to the adjustments. Turn the maximum output trimpot to the counter-
clockwise position for minimum range. Turn the setpoint knob to full clockwise position. Enable the
controller. Turn the maximum output trimpot until the desired maximum flow rate is achieved.
4. OPERATION
To energize the MagnaValve the MC controller must be enabled. This can be done with the mode
switch (1-5) by placing it into the ON position or by placing the mode switch into the READY position
and applying a 120 Vac to the ENABLE screw terminal #3. The LED labeled "Enable" will indicate
that the enable signal is present (1-1).
The flow rate command can come from the front panel local setpoint knob or a remote 0-10 Vdc
command. The LED's (1 - 3) and (1 - 4) indicates which command is active. Switch (2 - 1) is used to
select local or remote command. The remote analog command is applied at screw terminal #10 with
common at screw terminal #9.
A red LED (1 - 2) is provided to indicate status of the output signal to the MagnaValve. It will be off
for no-flow, blinking for low flow rates and constantly on for maximum flow rate. The signal is a fixed
frequency variable duty cycle (PWM) type of output. Longer "on" times provide larger flow rates.