Data Flow Systems TCU800, Installation And Operation Manual, Page: 124 / 162

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A p p e n d i x I
I. TCU Transducer Configuration Examples
The examples in this appendix are the most typical applications and can be used as a guide for configuring your system to
obtain the pump control and fault mode behavior required.
Note: The examples provided here are for systems in “pump down” mode (used to empty a well as is typical in a lift
station).
4-20 mA or 0-5 VDC Transducer with High Float (Pump Down Mode)
This is the most common configuration, combining a 4-20 ma or 0-5 VDC transducers with a high level float in the well to
prevent overflow and generate a high well alarm. Fault mode is disabled in this configuration. An optional low level float
to prevent pumping the well dry can also be applied.
High float events generate a transducer fault and high well alarm and stagger on all configured pumps. The pumps will
remain on as long as the high float condition exists. To prevent short cycling on high float transitions, the pumps adhere
to the configured minimum run and minimum off timers. In the example below the pumps will run a minimum of one
minute and remain off a minimum of 30 seconds regardless of the frequency of float transitions. Minimum run and off
timers apply to all pump operations – not just fault conditions – so these timers should be set considering the pump and
well characteristics during normal pump cycles. Conversely, low float events shut off all pumps.
Note: If a high and low float condition exist simultaneously the low float condition takes precedence and no pumps will be
started. If the transducer is a bubbler system, an optional Noise Fault configuration can be enabled to sense a bubbler pump
failure and generate a transducer fault alarm.
RS-485 Pins
Name Setting Description For more information, see...
Transducer Type 4-20 mA or 0-5 V Select 4-20 mA or 0-5 V for
systems using analog transducers.
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Low Float Enabled or Disabled Enable this setting to use a
lowlevel float to override normal
pump control if a transducer fault
occurs.
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High Float Enabled Enable this setting to use a
highlevel float to override normal
pump control if a transducer fault
occurs.
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Fault Mode Disabled Disable this setting if the system
isn’t using a backup method
(other than low- and/or high-
float) for pump control when a
transducer fault occurs.
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Transducer High Float Fault Enabled Enable to generate a transducer
fault when a high float condition
occurs.
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