Corrective Action; Sensor Cable Resistance Test - GF UD2100 Betriebsanleitung

Operating Instructions
METER READING TOO HIGH
Possible Causes
Calibration error
Pipe is not full
Nearby velocity increasing device (pump,
valve, orifice plate)
Local electrical noise
Variable Speed Drive interference
METER READING DOES NOT TRACK FLOW
Possible Causes
Sensor and GND wires reversed or not
properly connected
Improper AC power input Ground
7.2

Sensor cable resistance test

Unplug the green sensor terminal from the
Doppler board and connect the sensor wires
as shown. With a multimeter, perform resis-
tance checks for each set of wires. One sin-
gle loose terminal may cause false read-
ings.
Test across shield and core of each wire:
TMTR (black/white) and RCVR (black). Re-
sistance should be around 82.5K ohms for
any cable length. High readings indicate an
open circuit and low readings indicate a
short or partial short in the sensor cable.

Corrective Action

• Review UNITS/MODE menu and Pipe ID.
• Remount Sensor on vertical pipe.
• Relocate sensor >30 pipe diameters from velocity increasing device.
• Ensure all Flowmeter wiring is in METAL conduit and sensor cable shield is
connected to Ground stud.
• Follow Drive manufacturers wiring and Grounding instructions.
• Relocate Flowmeter electronics, Sensor and wiring away from VSD
Corrective Action
• Check Sensor connections
• Use direct connection with 12 AWG wire to nearest Ground pole (<1 ohm
resistance).
UD2100 Ultrasonic Doppler Flow Meter
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