Electronics MC - Manual (Page 5)

H:\MANUALS\IM0049C.DOC Installation Manual Model MC Shot Flow Controller 5 of 12
Use a clamp-on type ammeter to verify panel meter ammeter reading. Occasionally, the
number of wraps of wire around the panel meter current transformer is incorrect, or the current
transformer ratio is not correct for the load amperage and meter range. Also, have someone verify that
the amperage target is correct. Usually, the Almen strip is used as primary process verification and
ammeter readings are subordinate. If Almen strip arc height, percentage of piece part coverage, and
process time are acceptable, what should the wheel amperage be?
Shot condition is very important. Unclean shot, due to oil, water or dust, can cause erratic flow
performance. The dust can be generated by shot deterioration, or by abrasion of the parts being
peened or the cabinet or tooling. The dust will tend to cake and clog the flow. Under severe
conditions, the MagnaValve may become completely blocked.
2. SYMPTOM: Setpoint does not control flow rate.
a. Green LED (1 - 3) "Local" or Yellow LED (1 - 4) "Remote" should be on for local
setpoint knob operation.
b. Enable signal must be present (Screw Terminal #3). Also, the "Enable" LED must be
lighted (1 -1).
c. MagnaValves operate using a magnetic field and have no moving parts. High differential air
pressure caused by wheel rotation causes suction, which may suck shot through the valve. This
symptom is characterized by having shot flowing when valve is off (red valve LED = off). It may be
necessary to provide an aspiration air inlet below the MagnaValve. Contact factory for advice.
d. MagnaValve valve driver module may be defective. The valve driver module is factory set
and is used to regulate the precise amount of current necessary to cancel the permanent magnet field in
the MagnaValve. If this module fails there may be no current or excessive current. The correct output
current setting is listed on the valve driver module. Check the valve current with an ammeter in series
with wire lead from the controller (screw terminal #7) to the valve driver module (screw terminal #1).
The dc current should be within 10% of the listed value. If it is not, try to adjust it using the trimpot
located on the valve driver module. If this does not change the MagnaValve current then replace the
valve driver module. The new valve driver module must be set to the value listed on the old valve driver
module to properly operate. Contact factory for assistance.
3. SYMPTOM: Cannot achieve any flow, or flow rate is very low.
a. Enable light must be on (1 - 2).
b. Green LED for "Local" or Yellow LED for "Remote" setpoint must be on.
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" check the current going to the valve driver module and see that it matches the label on the valve
driver module.
e. Check for contamination in or above MagnaValve, especially check for water, oil, or dust
mixture in the shot.
f. MagnaValve or valve driver module may be defective. To check, remove valve from machine
(keep wires attached). Enable the output and get red LED valve "on" at 100% duty cycle. When