Data Flow Systems TCU800, Installation And Operation Manual, Page: 129 / 162

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T C U T r a n s d u c e r C o n f i g u r a t i o n E x a m p l e s
Concurrent
transducer high and
low float conditions
(with low float
option enabled)
• Transducer fault
alarm
• Low well alarm
• High well alarm
All pumps off Control switches to float inputs. Transducer
fault, low well, and high well alarms are
generated. The Low float takes precedence,
and all pumps are turned off. Pumps remain
off while the Low float is off. If Off/Lead float
activity does not occur, the TCU will not start
the pumps until a reset clears the transducer
fault.
Concurrent low
float and high float
conditions (with
low float option and
enabled and high
float override option
disabled)
• Transducer fault
alarm
• Low well alarm
• High well alarm
All pumps off Control switches to float inputs. High well, low
well, and transducer fault alarms are generated.
The Low float takes precedence, and all pumps
are turned off. If the low float condition clears,
but the high float condition remains, the pumps
are not started. If Off/Lead float activity does
not occur, the TCU will not start the pumps
until a reset clears the transducer fault.
Concurrent low
float and high float
conditions (with
low float option and
high float override
options enabled)
• Transducer fault
alarm
• Low well alarm
• High well alarm
All pumps off Control switches to float inputs. High well, low
well, and transducer fault alarms are generated.
The Low float takes precedence, and all pumps
are turned off. If the low float condition clears,
but the high float condition remains, the pumps
are not started. If Off/Lead float activity does
not occur, the TCU will not start the pumps
until a reset clears the transducer fault.
4-20 mA or 0-5 VDC Transducer with Analog Input 2 as Backup (Pump Down Mode)
This configuration applies to 4-20 mA or 0-5 VDC transducers. It uses the TCU’s second analog input to operate the
pumps in the event of a transducer fault. The second analog input can be wired to any analog level transducer, including a
redundant bubbler system, but the signal must be 4-20 mA. Optional High and Low level floats can be used for alarm and
limited backup control to prevent overflow in the event of both transducers failing.
Notes:
• The TCU will locally alarm the second analog input if the input is not within operational 4-20 mA range. There is
not a separate “Analog Input 2 Fault” I/O point for telemetry as of this code revision. It is recommended that the
second analog input be configured in telemetry to alarm on Low and High thresholds when configured as the backup
transducer.
• Once a transducer fault has occurred, the TCU will remain on second analog input control until it has been reset.
Response to Fault Conditions (Transducer with Floats Backup)
Name Setting Description For more information, see...
Transducer type 4-20 mA or 0-5
Volts
Select 4-20 mA or 0-5 Volts for systems using
analog transducers.
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