Electronics MC - Manual (Page 6)

H:\MANUALS\IM0049C.DOC Installation Manual Model MC Shot Flow Controller 6 of 12
Valve LED is on, the magnetic field should be perfectly canceled. No shot should stick inside the
MagnaValve. If any shot sticks to the valve, then either the valve driver module or the MagnaValve is
defective. Measure the dc current going to the valve driver module in the red wire. This should be
approximately 0.5 to 0.7 Amps dc. Compare your measurement to the value written on the label of the
valve driver module. If your reading is not within 10%, then the valve driver is defective or not adjusted
properly. Try adjusting the drive current to the listed value. If the current does not change with
adjustment then the valve driver module is defective and must be replaced. Be sure the replacement
valve driver is pre-calibrated to the same value as the original module. If your reading is within 10% of
the original valve driver calibration, the valve driver module is OK but the valve is defective.
4. SYMPTOM: Often have high flow or flow continues when setpoint is reduced or enable is turned
off.
Valve is leaking shot.
a. This is usually caused by pressure difference across the valve. Some wheels at some speeds
and flow rates tend to provide a large vacuum and this may suck shot through the MagnaValve. Relieve
this negative pressure by providing a hole (1/2" diameter) in the hose immediately below the
MagnaValve. This allows aspiration air to help convey the shot to the wheel inlet.
5. SYMPTOM: Shot flow rate is erratic or unstable.
a. Check shot for cleanliness.
b. Check shot for cleanliness.
c. Check shot for cleanliness.
d. Check valve driver module and MagnaValve.
e. Call the factory for advice.
NOTE: This category is the most challenging to trouble shoot. We have found that shot
cleanliness and foreign objects are usually responsible. Items, such as: wire (from identification
tags), welding rod, nuts-bolts from machine or screen separator, masking tape, razor blades,
milk cartons, cigarette butts, etc. seem to find their way into the MagnaValve.
FIGURE 1. FRONT PANEL - Operator Controls
ITEM DESCRIPTION
1. ENABLE - This LED indicator will be on if the mode switch is "On" or in the "Ready"
position and customer applies 120 Vac to control enable screw terminal #3.
2. VALVE - This LED indicator shows power output to the MagnaValve at variable duty cycle.
(When this LED is off, the permanent magnet in the MagnaValve holds the shot and there is no
flow. When this LED is on, the MagnaValve solenoid cancels the permanent magnet and you
have maximum shot flow. When this LED is blinking, the shot flow rate is being regulated.)
3. LOCAL - This LED indicator shows that the control is in the "Local Mode" and the setpoint
knob below it will command the shot flow rate.