Instruction Manual
MAGNAVALVE FOR WHEEL BLAST MACHINE
SHOT FLOW CONTROL
Electronics Inc.
56790 Magnetic Drive
Mishawaka, Indiana 46545
1-800-832-5653 (Toll Free)
Phone: 1-574-256-5001
Fax: 1-574-256-5222
E-mail: sales@electronics-inc.com
Website: www.electronics-inc.com
IM:0091 Revision: A Date: 11/2/2007
Made in the USA
500-24 MagnaValve
Table of Contents
PRODUCT DESCRIPTION
3
THEORY OF OPERATION 3
LOCATION OF ADJUS TMENT S
PRELIMINARY ADJUSTMENTS
INSTALLATION
OPERATION
CALIBRATION
3
4
4
3
3
SPARE PARTS LIST 4
TROUBLE SHOOTING GUIDE
MAINTENANCE
4
4
FRONT PANEL DESCRIPTION
FIGURE 1 FRONT PANEL
5
5
WIRING CONNECTIONS 6
2
1. PRODUCT DESCRIPTION
The 5xx-24 Series of MagnaValves are designed to regulate the flow of steel shot or grit in
abrasive blast cleaning and shot peening machines. The valves have a magnetic control section (upper portion) and a shot flow rate sensing section (lower portion). Valves are sized by
flow rate capacity, either in pounds/minute or in Kg/minute, and are used in air-blast applications such as direct pressure, suction blast or gravity-fed nozzle blast machines.
MagnaValve Model Output = 4.54 Vdc Output = 5.00 Vdc
Specify calibration in pounds/minute or Kg/minute and type and size of shot with order.
Note: All MagnaValves are factory calibrated to Kg/min=10 Vdc. To
change to pounds/min see instruction manual for the FC-24 Controller.
Flow Range
500-24 1200 Lbs/min 500 Kg/min
2. THEORY OF OPERATION
MagnaValves have no moving parts, they rely upon very strong permanent magnets and cancellation electromagnets to regulate the flow rate of shot. A signal from a shot flow controller,
model FC-24, will provide the appropriate control signal for flow rate. Power is supplied by an
external (supplied by customer) 24Vdc source. The internal circuitry accepts a 0-10Vdc control
signal and converts this to a proportional duty-cycle control of the output signal for shot flow. As
the shot falls through the lower sensing portion of the valve, a 0-10Vdc signal is generated and
sent back to the FC-24 controller as a flow feedback signal. This feedback signal is compared
to the requested shot flow rate and the output signal is adjusted and sent back to the MagnaValve to complete the closed-loop cycle of control.
3. LOCATION OF ADJUSTMENTS
All of the adjustments are accessible from the front of the MagnaValve. See figure 1 for details.
The factory settings should not be changed. The rated flow range is shown on the identification
label. The output signal is 10 Vdc. for Kg/minute calibrated valves and 4.54 Vdc for pounds/
minute calibrated valves.
4. PRELIMINARY ADJUSTMENTS
There are no preliminary adjustments required or recommended. The valve has been tested
and calibrated at the factory prior to shipment. The full-scale range of the valve and the media
type and size are listed on the product label.
5. INSTALLATION
The MagnaValve must be mounted in a vertical position with an adequate supply of media
above it. Pipe unions are recommended to allow correct alignment of the valve. The valve can
be used for all three types of air blast machines, (direct pressure, suction nozzle and gravity assisted suction nozzle).
a. For direct pressure applications a suitable mechanical grit valve or pinch-tube type of shut-
off is necessary to prevent the air pressure from forcing media through the magnetic field.
The mechanical valve can be located either above or below the MagnaValve.
b. For suction blast applications (valve located on floor) an aspiration air inlet must be pro-
vided so the media can be conveyed to the nozzle. A minimum opening of 12mm is recommended. Do not restrict this air inlet since it will increase the suction and may pull media
through the valve.
3
c. For gravity assisted applications (valve located on the top of blast cabinet below the media
hopper) an aspiration air inlet must be provided so media can be conveyed to the nozzle. A
minimum opening of 12mm is recommended. Do not restrict this air inlet since it will increase
the suction and may pull media through the valve.
6. OPERATON
Signals used to operate the MagnaValve originate at the FC-24 Controller. There are three conditions necessary for correct operation. See figure 1 for additional information.
a. Power – The 24 Vdc power must be continuously applied to the valve. The valve requires 1.4
amps for operation and a power supply rated at 50 VA. The voltage should be 24 ± 2 Vdc.
b. Enable – The 24 Vdc enable signal is used to activate the valve.
c. Input Signal – The analog 0-10 Vdc input signal must be above 0.25 Vdc as a minimum flow
command signal.
For additional information about the MagnaValve consult the FC-24 installation manual.
7. CALIBRATION
Calibration of the MagnaValve is done by a catch-and-weigh test. Media is allowed to flow
through the valve for a timed period, usually one minute. The shot is weighed and compared to
the requested amount. Adjustments are made at the MagnaValve Gain Select switches and adjustment knob. Note: Full scale output of the valve for Kg calibrations is 10 Vdc while full scale
output for pound calibration is 4.54 Vdc. This lower value is adjusted with the FC-24 span by setting the gain to 1.100. See the FC-24 Installation Manual for more information.
8. SPARE PARTS LIST
There are no spare parts for this series of MagnaValves
9. TROUBLE-SHOOTING GUIDE
The primary trouble-shooting is accomplished by reporting the status of the 4-LED indicators on
the valve. They must all be ON in order for media to flow. If all of the LED’s are ON but there is
no media flow, check the following:
a. Is the mechanical valve (for direct pressure applications) functioning?
b. Is there media available from the hopper?
c. Is there any blockage above or below the MagnaValve or at the nozzle?
d. Are there any air leaks, especially above the MagnaValve when used with very small noz-
zles?
e. Is the magnetic field completely cancelled when the red LED is ON? Check this by removing
the valve from the machine and applying the proper signals for 100% flow.
10. MAINTENANCE
The only regular scheduled maintenance for a MagnaValve is annual re-calibration.
11. FRONT PANEL DESCRIPTION
The front panel of the MagnaValve contains the four LED’s used for diagnostics. The large
knurled screw on the front cover may be removed to gain access to the factory adjustments.
Please refer all adjustments to qualified personnel. Changing the gain will affect the valve calibration accuracy and should only be done when catch-and-weigh test results are available. See
figure 1 for additional information.
4
Zero – turn adjustment until both
LED’s are OFF. This will set the
output signal to zero ± .050 Vdc
during no-flow.
Gain – This section controls the
amplification or gain of the sensor
signal. It has been factory set (see
label for flow range). If the gain is
changed it will be necessary to run
a one‑minute catch‑and‑weigh
test to confirm the calibration. The
full scale output signal is set to 10
Vdc for kg calibration.
Note: be sure only one gain switch
is selected (up position). Use the
“Gain Adjust” for fine adjustments.
EI also offers an exchange calibration service. Contact the factory for
more information.
Valve Pulse – This is the rate at which the
valve dispenses shot, similar to a heart
beat rate. It is factory set to match the best
flow characteristics of the media (cast steel,
cut wire or micro-bead). Typical operation
is set at 12-15 Hertz or mid-scale setting of
the adjustment.
Test Socket – This socket provides
access to diagnostic voltages.
0-10 Vdc input
0-10 Vdc output
24 Vdc “Enable” input
6-20 Hertz pulse rate
0 Vdc common
Diagnostic LED’s
VALVE ON – This LED is on when power is sent to the electromagnet. When the LED is off the permanent magnets
will hold or block the shot flow. When the LED is on the valve is on for full capacity flow rate. When the LED is blinking then the shot flow is being regulated.
Vin > 0.25 Vdc- This LED indicates that an analog signal input greater than 0.25 Vdc has been received. When this
LED is off there is no media flow allowed. The input signal range is 0-10 Vdc. At 10 Vdc the valve will “open” to full
capacity which is usually 25% to 50% higher than the calibrated range. The relationship between the 0-10 Vdc input
signal and actual flow rate is non-linear. The output signal 0-10 Vdc signal is linear and this make s accurate regulation by the FC-24 control possible.
24 Vdc ENABLE – This LED indicates that the 24 Vdc Enable signal has been received. When this LED is off then
the valve is inhibited, no shot will flow. This feature is provided as an on-off action so that you do not have to disable
or remove the 0-10 Vdc input signal.
24 Vdc Power – This LED indicates that 24 Vdc is available to operate the electromagnets for media flow. It should
always be available and able to supply 2 Amps.
All of the LED’s must be on in order to have media flow.
5
SPECIFICATIONS
6.8
7.30
INPUT:
ENABLE: 24VDC
FLOWCOMMAND: 0-10VDC
POWER: 24VDC@ 2A (50VA)
ADJUSTMENTS:
SPAN
PULSE RATE
OUTPUTS:
FLOW SIGNAL: 0-10VDC
ACCURACY: ±2% FULL SCALE
FLOW RANGE: 120-1200LBS/MIN
MEDIA: CAST STEEL SHOT
CUT WIRE SHOT
MODE: NORMALLY CLOSED
TEMP RANGE: 40-110 F
ZERO
5-43 C
9.00
"O" RING 5.5 I.D.
3.18
9.38
5.63
ø5.000
6.60
.562
1.00
Note: The MagnaValve is designed
to operate vertically must be
mounted within 5 degrees of vertical.
FRONT VIEW COVER REMOVED
Valve ON
Vin >.25Vdc
24Vdc Enable
24Vdc Power
Pulse Rate
(Factory set)
WIRE CONNECTIONS
FC-24 500-24
6. PROCESS IN 0-10V 1. WHITE 0-10VDC OUT
5. PROCESS 0VDC 3. GREEN 0VDC
8. SERVO OUT 4. ORANGE 0-10VDC IN
9. VALVE ENABLE 6. BLUE 24VDC ENABLE
19. 24VDC SUPPLY 2.RED 24VDC SUPPLY
20. 0V COMMON 5. BLACK 0V COMMON
ZERO (Factory set)
SPAN (Factory set)
4
3
2
1. WHITE
2. RED
3 . GREEN
4. ORANGE
5
6
NOTE:
• Make connection from power
supply directly to the MagnaValve to prevent high current
voltage drops.
• Use 16 AWG or larger wire size
for connection to the controller.
• Be sure Power supply is regulated and capable of 2Amp
(50VA) output.
1
5 . BLACK
6. BLUE
See FC-24 Data Sheet for more information
6
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