Seametrics FT500-Series - Manual (Page 4)

> FT520 Batch Controller
In Batch Processing Mode, the display indicates a flow rate on
the top line, and one of three user-selectable configurations
on the bottom line: an accumulated total flow (resettable), ac-
cumulated batch flow, or batch process bar graph. The batch
output is controlled via two relays. The main relay starts and
stops the batch as a set, or the auxiliary “prewarn” relay can
be used to operate a second valve. This allows increased ac-
curacy by engaging a staged shut off at the end of the batch.
Settings
Use left arrow and up arrow keys to change settings. Press
SET to advance to next menu.
- SET Batch Size
Set the batch size for the desired number of units. If the
staged shut-off feature is not being used, this is the only set-
ting required for the batch.
- SET Prewarn Size
This is only used for a staged shut-off. The number set is the
number of units early (before the end of the batch) that Relay
2 will shut off.
- SET Flow/Rate
Select the particular volume unit desired (gallons, liters, etc.).
Then switch to time units and select the time unit desired
(minutes, hours, etc.).
- SET Decimal
Select none, one, or two decimal places on the flow units.
- SET K-Factor
The unit will not function properly until this number is entered.
The K-factor is simply the number of pulses which the flow
meter or flow sensor puts out per gallon of liquid. It is marked
on the Model/Serial tag of Seametrics flow meters and flow
sensor fittings. On adjustable depth flow sensors, the K-factor
must be taken from the chart in the flow sensor instructions,
based on pipe size.
- SET Pulse (scaled) Output 1
An output pulse is activated at the selected volume intervals
if this feature is in use. If a pulse output is not needed, pulse
out does not need to be set.
- SET Pulse (scaled) Output 2
An output pulse is activated at the selected volume intervals
if this feature is in use. If a pulse output is not needed, pulse
out does not need to be set.
- SET 20 mA Rate
The “SET 20mA RATE” programs the maximum flow rate at
which the output is 20 mA full scale, at 5 V or 10 V.
- Clear Total
This function resets the accumulated total back to zero. It is
unrelated to the regeneration function, and can be ignored
unless it is needed.
Operation
Start Batch. Pressing the Start/Stop key starts the batch by
energizing Relay 1. The indicator for Relay 1 will light, indicat-
ing normal operation. The indicator for Relay 2 may also light,
depending on the prewarn setting. If staged shut-off is being
used, the Relay 2 indicator light should go out before the end
of the batch, at the prewarn set point. The batch will continue
on to the set amount unless it is halted in the middle of the
process by pressing the Start/Stop key again.
Stop Batch/Resume Batch. Pressing the Start/Stop key any-
where in the batch will stop it. It will remain stopped until the
Resume key is pressed. Pressing the Start/Stop key again
allows the batch to restart from zero.
Choice of Displays for Batching. When in Operation Mode,
press the UP Arrow to change the type of display. Running
Totalizer (“T”) accumulates a Total Flow until it is reset. Batch
(“B”) accumulates the flow of the present batch only, then
resets. Bar Graph (“❚”) graphically indicates from left to right,
how much of the batch has already accumulated.
Page 3
FT520
STAGED SHUT-OFF APPLICATION
TX Flow Sensor
High-Flow
Valve
Low- Flow
Valve
Tank
FT520
Staged shut-off
at end of batch
High-Flow Valve
Low-Flow Valve
Relay 1
Relay 2
NC
COM
NO
NC
NO
COM
Power
Source
+ -
CONNECTION FOR STAGED SHUT-OFF