Electronics AC - Manual (Page 13)

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13. CALCULATING FLOW RATE IN POUNDS/MINUTE
To determine the pounds per minute flow rate perform a catch and weigh test. A large con-
tainer in which to catch the shot for at least 15 seconds of flow will be needed. Since the AC
controller is a current controller and not a flow rate controller, some extra steps to determine
the effective shot flow rate will be required.
a. Select an amperage setting that is typical of the operation. Place the servo switch in the
off (down) position. Place the setpoint knob at its minimum setting. Start the wheel and
slowly increase the output using the setpoint knob until the desired amperage is achieved.
b. Stop the wheel and remove the feed hose from the wheel feed spout and aim it at the
catch bucket.
c. Caution: Do not start the wheel.
d. Enable the controller, flow shot for 15 seconds and catch it in the bucket.
e. Weigh the shot, subtract the (empty) bucket weight, and multiply by 4 to get pounds/
minute.
f. Repeat the test to assure accuracy.
g. Reassemble the hose to the feed spout and return the servo switch to the ON position
(up).
NOTE
: The above procedure only works because the servo is turned off. In this mode the set-
point knob sets the output manually and ignores the motor amperage feedback signal, which
during the catch and weigh test is zero. The procedure works because the flow rate is estab-
lished manually with the wheel motor current. In order to select another flow rate it will be nec-
essary to have the feed spout in place and manually set the output to a new condition.