Instruction manual

36 RFT9709 Transmitter Instruction Manual
Troubleshooting
continued
Table 4-2. Normal resistance for flowmeter circuits
Table 4-3. Input and output ratings
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.
Circuit Wire colors Sensor terminals Nominal resistance range
Drive Coil Brown to Red 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 35 to 175Ω depending on process fluid
Lead Length Compensator Yellow to Violet 4 to 7 35 to 175Ω depending on process fluid
Transmitter terminal
number Input or output Approximate value
1 to 2 Drive signal output to sensor 1.2 to 14 V peak-to-peak at flow tube natural frequency
3 to 4 Lead length compensator input 10 mVDC maximum
5 to 9 Left pickoff input 3.4 mV/Hz peak-to-peak sine wave
6 to 8 Right pickoff input 3.4 mV/Hz peak-to-peak sine wave
7 to 4 Temperature input 30 mV at 0°C, +0.14 mVDC per °C
Power terminals (+ to –) Line voltage input 11 to 30 VDC
11 to 12 Primary mA output 4-20 mA
13 to 14 Secondary mA output 4-20 mA
15 to 16 RS-485 I/O ±5 V square wave
17 to 18*
*Optional configuration
Frequency/pulse output 23 VDC peak-to-peak square wave (+23 VDC at zero flow)
19 to 18* Zero in progress 23 VDC when not in progress, 0 VDC when in progress
19 to 18* Flow direction output 23 VDC with forward, 0 VDC with reverse
19 to 18* Alarm output 23 VDC normal, 0 VDC with fault
20 to 18* Remote zero input 23 VDC
21 to 22* Pressure transmitter input 0.3 to 11 VDC
09shoot.fm Page 36 Tuesday, March 2, 1999 9:26 AM