2-90
1010PVNFM-3A
Section 2
Detection Fault/Low Signal
q Perform all checks for “Low Valc”
q Ensure pipe is full.
q Ensure cables are terminated at both ends; Check continuity with Ohmmeter.
q Check operation on Pipe Simulator.
q Switch off any radiating electrical equipment in area (Transmitters, Variable Freq. Drives,
etc.).
High Vaer
q Avoid transducer mounting near flow obstructions.
q Check for possible pressure drop sources (Pipe Expansion, Orifice, Check Valve, etc.).
q Check liquid “Flash Point” against application conditions.
q Pinch downstream valve (of Transducer) to raise pressure.
q Mount on suction side of pump.
q Raise tank levels; adjust Float switches.
Low Valc
q Clean and condition pipe surface.
q Use recommeded High Precision or first recommended Universal Transducer.
q Use Direct Mount (be sure of transducer 180º alignment!).
q Use larger size transducer (Universal Only!).
q Use wider spacing (Maximum or Letter D).
q Stop flow to check for Aeration/Cavitation.
q Try another location.
q Perform an Initial Makeup after ANY of the above changes!!
q Verify Graph is acceptable (see below).
q Use recommeded High Precision or first recommended Universal Transducer.
q Verify Liquid Vs in database (take into account actual temperature & pressure).
q Verify Liquid chemistry is as expected. (Ask about additives, Pressure, Temp.)
q Try “1-Cycle” Vs Correction in Diagnostics if error remains for a liquid with well defined
Vs data.
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