Emerson IFT9701 instruction manual Normal resistance and voltage ranges for flowmeter circuits

Troubleshooting continued

Table 8-3 Sensor terminal designations

Terminal number	Wire color	Function
1	Brown	Drive +
2	Red	Drive –
3	Orange	Temperature –
4	Yellow	Temperature lead length compensator
5	Green	Left pickoff +
6	Blue	Right pickoff +
7	Violet	Temperature +
8	Gray	Right pickoff –
9	White	Left pickoff –

To check integrity of sensor wiring circuits:

1.Disconnect the transmitter's power supply.

2.Disconnect sensor wiring from the transmitter's intrinsically safe terminal block in the sensor wiring compartment. See Figure 8-1.

3.Use a DMM to measure resistance between wire pairs, as indicated in Table 8-4.

4.If the transmitter is remotely mounted from the sensor, repeat the measurements at the terminal block in the sensor junction box to distinguish cable failure from sensor failure.

Table 8-4 Normal resistance and voltage ranges for flowmeter circuits

Notes

•Temperature sensor value increases 0.38675 ohms per °C increase in temperature.

•Nominal resistance values will vary 40% per 100 °C. However, confirming an open coil or shorted coil is more important than any slight deviation from the resistance values presented below.

•Resistance across terminals 6 and 8 (right pickoff) should be within 10% of resistance across terminals 5 and 9 (left pickoff).

•Resistance values depend on the sensor model and date of manufacture.

		Sensor
Circuit	Wire colors	terminals	Nominal resistance range
Drive coil	Red to brown	1 to 2	8 to 2650Ω
Left pickoff	Green to white	5 to 9	15.9 to 300Ω
Right pickoff	Blue to gray	6 to 8	15.9 to 300Ω
Temperature sensor	Orange to violet	3 to 7	100Ω at 0°C + 0.38675Ω/°C
Lead length compensator	Yellow to violet	4 to 7	100Ω at 0°C + 0.38675Ω/°C

8.6Over range and sensor failure conditions

If a sensor failure occurs, if the flowmeter cable is faulty, or if flow, temperature, or density goes outside the sensor limits, all the following occur:

•The transmitter produces fault outputs.

•The diagnostic LED blinks ON 4 times per second.

•The optional LCD reads “SENS0”.

Flowmeter Startup

Configuration with Communicator

Configuration with ProLink II

Troubleshooting

Model IFT9701 Transmitter Instruction Manual 61