Diagnosing Wiring Problems; Checking The Power-Supply Wiring; Checking The Sensor-To-Transmitter Wiring - Emerson Micro Motion 2700 Configuration And Use Manual

Troubleshooting
6.9

Diagnosing wiring problems

Use the procedures in this section to check the transmitter installation for wiring problems.
Installation procedures are provided in the manual entitled Model 1700 and Model 2700 Transmitters:
Installation Manual.
Removing the wiring compartment covers in explosive atmospheres while the power is on can cause
an explosion. Before removing the field wiring compartment cover in explosive atmospheres, shut off
the power and wait five minutes.
6.9.1

Checking the power-supply wiring

To check the power-supply wiring:
1. Verify that the correct external fuse is used. An incorrect fuse can limit current to the
transmitter and keep it from initializing.
2. Power down the transmitter.
3. If the transmitter is in a hazardous area, wait five minutes.
4. Ensure that the power supply wires are connected to the correct terminals. Refer to the
installation manual.
5. Verify that the power-supply wires are making good contact and are not clamped to the wire
insulation.
6. Inspect the voltage label on the inside of the field-wiring compartment. Verify that the voltage
supplied to the transmitter matches the voltage specified on the label.
7. Use a voltmeter to test the voltage at the transmitter's power supply terminals. Verify that it is
within specified limits. For DC power, you may need to size the cable. Refer to the installation
manual for information about the transmitter power supply.
6.9.2

Checking the sensor-to-transmitter wiring

Note: This does not apply to flowmeters with an integrally mounted transmitter.
To check the sensor-to-transmitter wiring, verify that:
• The transmitter is connected to the sensor according to the wiring information provided in the
installation manual.
• The wires are making good contact with the terminals.
• For 4-wire connections, the mating connector between the core processor and the transmitter is
securely plugged into its socket.
If the wires are incorrectly connected:
1. Power down the transmitter.
2. Wait five minutes before opening the transmitter compartment if the transmitter is in a
hazardous area.
3. Correct the wiring.
4. Restore power to the transmitter.
102 Model 2700 Transmitter with PROFIBUS-PA