AUTOMATIC
FLIP-FLOP TWO
SCALE SYSTEM (2
speed feed)
EXPRESS SYSTEM 303 SEQUENCE OF OPERATION
Tare A, Tare B; Feed A, Slow Feed A & B, Fast Feed B, Slow Feed A & B.
- Place
an empty container on scale (or both scale) and switch ON/OFF to ON.
- Empty
container(s) will satisfy "container in place" weight threshold interlock.
Witch causes Automatic Tare to Net Weight Zero, witch then sets the
scale to run it's logic sequence.
- Press
START to begin production. The system will turn on the feed pump and
begin product flow.
- Simultaneous
with feed pump start, Scale A feed valve will open and begin Fast Feed.
- Scale
A Fast Feed will continue until the Slow Feed weight set-point is achieved,
at witch time the Scale B feed valve are open. At this point, both the
Scale A and Scale B feed valves are open. Because product flow rate
is provided at a continuous rate by the pump, and because the flow rate
is split between the two valves; the effect is Slow feed (at approximately
50% of Fast Feed) to both Scales A & B. Scale A is being "topped off"
at Slow Feed, Scale B is being initially filled at Slow Feed. The result
is a constant product flow rate thought the Scale A Slow Feed cycle.
- When
Scale a fills to it's Final weight set-point, the Scale A valve is turned
off, resulting in fast Feed on Scale B. Scale a has completed its fill
cycle.
- Remove
the fill container from Scale A Scale A will return to Zero, instantly
resetting for a new cycle. Placing a new empty container on scale a
will once again satisfy the "container in place" weight threshold interlock
which causes Automatic Tare to Net Weight Zero. Scale a is now ready
to receive the flip-flop command to receive fill when Scale B goes to
Slow Feed (witch again opens both valves).
- The flip-flop
sequence between the two scales will continue unless:
A. The Stop button is pressed, which closes any open valves, which then causes a "both valves closed" interlock to stop the pump. Press START to resume a "both valves closed" interlock to stop the pump. Press START to resume the process where it left off, or, Press the RESET key on the keypad if it is desired to cancel cycles in progress and start over.
B. IF a full container is remaining on scale, or IF no container is detected on the scale through the "container in place" interlock, feed will be prevented from switching to the scale. In either of these cases, the pump will be turned off. Removing the full container and (or) placing a new empty container will automatically cause the system to resume where it left off.
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