Electronics FC User Manual
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5. SYMPTOM: Cannot achieve any flow, or flow rate is very low.
a) “Enable” light must be on (1 -2).
b) Set point command must be present (check set point using toggle switch to right).
c) Red LED "Valve" should be bright and blinking or constantly on. An internal circuit breaker
has tripped if it is dim, Check for short circuit valve wiring at Terminals #7 and #8. To reset
the circuit breaker, remove and re-apply the “Enable” signal.
d) Check Red LED at MagnaValve junction box, if it is not "on", check for a wiring problem. If it
is "on" measure the current going to the valve driver module. It should be approximately
equal to the valve driver current written on the valve driver module label.
e) Check for contamination in or above MagnaValve, especially check for water, oil, or dust
mixture in the shot, or other obstructions.
f) MagnaValve or valve driver module may be defective. To check, remove the MagnaValve
from the machine (keep wires attached). “Enable” the output and get red LED valve "on" at
100% duty cycle. When Valve LED is on, the magnetic field inside the MagnaValve 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 re-
placement 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.
6. SYMPTOM: High flow alarm or flow continues when the set point is reduced or the
“Enable” is turned off.
The MagnaValve is leaking shot. This is usually caused by pressure difference above and below
the valve. Direct pressure air blast systems: The boost air pressure must be equal to the pres-
sure vessel pressure. Gravity fed (suction) air blast systems: The suction induced by some ven-
turi nozzles is quite large. Be sure there is a large (1/2") aspiration air inlet near the bottom of the
MagnaValve. The shot needs air to convey it to the nozzle. Older practice was to "choke" the
shot like a carburetor to get a richer flow rate. Since the MagnaValve acts more like a fuel injec-
tor, this choking is not required.
7. SYMPTOM: Shot flow rate is erratic or unstable.
a) New installations - refer to servo adjustments.
b) Old installations - machine worked fine until recently.
c) Check shot for cleanliness.
d) Check shot for cleanliness.
e) Check shot for cleanliness.
f) Do not adjust servo adjustments.
g) Call the factory for advice.
NOTE: This category is the most challenging to troubleshoot. Shot cleanliness and foreign ob-
jects are usually the problem. Items such as: wire (from identification tags), welding rod, nuts-
bolts from machine or screen separators, masking tape, razor blades, milk cartons, cigarette
butts, etc., seem to find their way to the valve. Remove the MagnaValve and inspect it for con-
tamination. Be sure the shot hopper does not have contamination.