Users Manual Part 1

Transmitter housing
The most effective grounding method is direct connection to earth ground with minimal
impedance. There are two grounding screw connections provided (see Figure 4-1).
Figure 4-1: Ground Screws
A
B
A. Internal ground screw
B. External ground screw
Cable shield grounding
Make sure the instrument cable shield is:
• Trimmed close and insulated from touching the transmitter housing.
• Continuously connected throughout the segment.
• Connected to a good earth ground at the power supply end.
Figure 4-2: Cable Shield
B
A
C
CC
D
A. Insulate shield and drain wire
B.
Minimize distance
C. Trim shield and insulate exposed drain wire
D. Connect drain wire to the power supply ground
Note
Do not ground the shield and its drain wire at the transmitter. If the cable shield touches
the transmitter housing, it can create ground loops and interfere with communications.
Reference Manual Electrical installation
00809-0100-4418
September 2022
Rosemount 3408 Level Transmitter 31