Data Flow Systems TCU800, Installation And Operation Manual

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C h a p t e r 7
• The mechanical auxiliary contacts on the motor controller’s starter contactor are functioning properly. If they have
been damaged and are stuck in the closed position, the motor controller will not receive the pump stop signal.
• The motor controller’s starter contactor is functioning properly. If it has been damaged and is stuck in the closed
position, the motor controller will not receive the pump stop signal.
If a sufficient Stop Fault has been configured and the starter contactor and its mechanical auxiliary contacts are determined
to be functional, the TCU may require factory service. See “Appendix H: Support, Service, and Warranty” for removal,
replacement, and servicing instructions.
Transducer Fault
The conditions that cause a transducer fault to be generated are based on the TCU’s configuration. A few of the conditions
that can cause a transducer fault are:
• Transducer low condition
• High float condition
• Absence of bubbler noise
The TCU provides several options for maintaining well and tank levels when a transducer fault occurs. Control pumps
using:
• High and/or low float
• Timer based on the station’s pumping history (average cycle per each hour of the day)
• Second analog transducer
• Float system (Off float and at a minimum a Lead or High float)
• Combination of a high and/or low float and the desired fault mode (timer, second transducer, floats)
The TCU uses the selected backup scheme until the problem with the transducer has been identified and fixed, and the
TCU has been reset.
These options and the conditions that generate a transducer fault are described in more detail in “Chapter 6: Operating
Procedures.”
If none of these options have been implemented (floats, timer, secondary transducer) and the primary analog transducer
malfunctions, the TCU will be unable to provide automatic control until the malfunction is resolved. The alarm light and
horn relays may be activated.
When using an analog transducer, measure the voltage across the and ANALOG- terminals. This voltage
should be 1-5 VDC for a 4-20 mA transducer and 0-5 VDC for a 0-5 VDC transducer. The voltage measured between the
and ANALOG- terminals should vary according to the well or tank level.
Only 4-20 mA transducers should have a jumper installed between the ANALOG- and SHUNT terminals. If you
are using a 0-5 VDC transducer, verify that the jumper is not installed.