Electronics inc 250-N, Instruction Manual

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The Pre-Amp is factory calibrated and should not require any customer attention. The full-
scale output voltage feedback signal of the Pre-Amp is 5.00 Vdc. The pre-amp uses an oscil-
lator circuit and inductive sensor to detect metal density (shot flow) and converts this frequen-
cy into a 0-5 Vdc output feedback signal.
3. Calibration
SUMMARY –
Set MagnaValve Pre-amp zero output
Set Pre-Amp span to achieve full-scale flow
Confirm accuracy (perform catch & weigh tests)
Full-scale flow range is the maximum flow, in pounds per minute, required for your installation.
See Table 2. The MagnaValve pre-amp has been factory calibrated and should not need ad-
justment. In the event re-calibration is desired the following steps should be followed.
A. With no shot flowing, adjust the zero trimpot to achieve 0VDC output feedback signal.
B. Perform a catch and weigh test to ascertain flow rate at maximum capacity.
C. Adjust the span trimpot if required. Repeat the catch test to confirm accuracy.
D. You must also match the Model FC Controller display to the MagnaValve pre-amp out-
put signal. The Model FC Control display is used for many different size MagnaValves
and therefore many display ranges are used. The FC Control display range can be
changed as required for any particular MagnaValve. For example, to change the model
FC Control display to 0-700 lbs/min full scale range.
E. Turn setpoint knob to 100% (Full CW).
F. Be sure the FC Control is in local mode, not remote mode. See the LED indicators on
the front panel and use the local/remote slide switch if necessary.
G. Push and hold display toggle until the FC Control display reads 700.
H. The Model FC Control front panel span adjustment is factory set so that a 5.00 VDC
signal input will display the proper full scale signal, such as 700.
To check this feature you may inject a precision 5.00VDC calibration control signal
from any suitable DC source. If the Model FC Controller display does not show the de-
The FC Controller span should not need adjustment.
Model 250-N 700 lb./min.
Model 500-N 1200 lb./min.
Model 577 2 lb./min.
Model 578 20 lb./min.
Model 579 100 lb./min.
Model 580 200 lb./min.
Model 590 300 lb./min.
Model VLP + 599-5.0 Sensor 1,000 lb./min.
Model LP + 599-5.0 Sensor 1,999 lb./min.
Model 1577 2 lb./min.
Model 1579 100 lb./min.
Table 2. Maximum Flow Rate