Metalfab Metatech MT-X-XXX Series Volumetric Screw Feeder - Manual (Page 3)

amperage for inrush consideration. 230/3 models will draw exactly double the
460/3 ratings.
DC Motors are available with field windings (shunt wound) or permanent
magnet, both are available in 90vdc (std _ Hp) and 180vdc (std 1Hp) armatures.
DC motor speed is modulated by varying the armature voltage from 0 to max,
15% speed should be considered the min speed for motor cooling considerations
Operation
After the Feeder is in place and wired, it is ready for operation. Units equipped
with electrically variable speed drives can have their speed adjusted at anytime,
i.e., with the unit stopped or in motion. The dial provides for setting screw
speeds to 1 part in 100. Speed is increased by turning the potentiometer in
clockwise rotation. Optional digital keypads for Local/Remote operation are
available, again consult the feeder specification and pricing sheets for options.
The hopper should be filled with the feed material and the potentiometer should
be set to 50%. The unit should be allowed to run for 5 minutes before a 1
minute sample is collected and weighed. It is suggested that 5 or more samples
be taken to assure the Feeder is operating properly. Once the feed rate is
known at 50%, the required rate may then be obtained by proper speed change.
The drive and, therefore, the feed rates are linear, hence, at setting of 50% the
Feeder will be operating at approximately half capacity. As an example, if at a
50% setting a 20#/minute rate is achieved and a 10#/minute rate is desired,
change the setting to 25% and a 10#/minute rate will be delivered. Take
samples at 3 or 4 settings and plot a graph, setting versus rate. From this
graph, any feed rate may be selected. This calibration should be done at the
end user application as material bulk density and condition due to prior steps in
the process will have an impact on the ÅgActual Discharge RatesÅh, approximate
rates are listed on the drawing on the final pages in the spare parts section of
this manual.
Warning: Keep hands clear of all moving parts. Serious injury can occur.