SMART Temperature Transmitter
PTT74-Ex Series User Manual
Sep.2020
10
www.faraboard .com
FAHM Co
.
Industrial Automation
Doc. PTT74-ExRev99/07M
2.3.3
Grounding
Use the following techniques to properly ground the transmitter signal wiring and case. Do
not run signal wiring in conduit or open trays with power wiring or near heavy electrical
equipment. It is important that the instrument cable shield be:
◆
trimmed close and insulated from touching the transmitter housing
◆
Connected to the next shield if cable is routed through a junction box
◆
Connected to a good earth ground at the power supply end.
For 4-20 mA HART output, the signal wiring may be grounded at any one point on the signal
loop or may be left ungrounded. The negative terminal of the power supply is a
recommended grounding point. Always ground the transmitter case in accordance with
national and local electrical codes. The most effective transmitter case grounding method is
a direct connection to earth ground with minimal impedance. Methods for grounding the
transmitter case include:
◆
Internal Ground Connection: The Internal Ground Connection screw is inside the FIELD
TERMINALS side of the electronics housing. This screw is identified by a ground symbol.
◆
External Ground Connection: Grounding the transmitter case via threaded conduit
connection is the second way that may not provide sufficient ground continuity.
