Emerson Series 3000 MVD User Manual

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Use the procedures in this section to check the transmitter installation for wiring problems.

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. If the transmitter is in a hazardous area, wait five minutes.

3. Ensure that the power supply wires are connected to the correct terminals. See the installation 

instructions.

4. Verify that the power supply wires are making good contact, and are not clamped to the wire 

insulation.

Consistently incorrect 
frequency measurement

Output not scaled correctly

Check frequency output scale and method. See 
Section 22.15. Verify that voltage and resistance 
match the frequency output load resistance 
value chart.

Incorrect flow measurement unit 
configured

Verify flow measurement unit configuration. See 
Section 22.13.

Erratic frequency 
measurement when flow is 
stable

RF (radio frequency) interference from 
environment

Cannot connect to RS-485 
terminals in service port 
mode

Terminals not in service port mode

Terminals are accessible in service port mode 
ONLY for a 10-second interval after power-up. 
Cycle power and connect during this interval.

Leads reversed

Switch leads and try again.

Transmitter installed on multidrop 
network

All Series 3000 devices on network default to 
address=111 during 10-second service port 
interval. Disconnect or power down other 
devices, or use RS-485 communications.

Device is secured (custody transfer 
only)

Change Series 3000 device to unsecured, or 
use RS-485 communications.

Cannot connect to RS-485 
terminals in RS-485 mode

Terminals not in RS-485 mode

For the first 10 seconds after power-up, the 
terminals are in service port mode. If a service 
port connection is made during this period, they 
remain in service port mode. Wait until 
10-second interval has expired, cycle power to 
the device to reset the terminals if required, or 
connect in service port mode.

Incorrect RS-485 configuration

After 10-second interval on power-up, the 
transmitter switches to RS-485 mode. Default 
settings are:

• Address=1
• Baud rate=9600
• Parity=odd

Use the display to check or change the RS-485 
settings (see Section 13.3), then set parameters 
appropriately in the remote device.

Leads reversed

Switch leads and try again.

I/O problems and remedies continued