Onicon FT-3500 - Installing Grounding Rings (Non-Conductive or Lined Pipes Only)

FT
-
3500 ELECTROMAGNETIC FLOW METER
ONICON Incorporated 727.447.6140 Page 20 onicon.com
3.2.6 Installing Grounding Rings (non-conductive or lined pipes only)
* Additional straight run may be required upstream of the upstream grounding ring based on the nature of the
upstream obstruction. Refer to the chart in Section 3.1 on page 11 of this manual to determine how much straight
run is required.
Grounding rings are used to suppress electrical interference at the installation location for electromagnetic ow meters. They
are provided in pairs and are installed upstream and downstream of the ow meter. The use of grounding rings signicantly
reduces electrical noise and may be necessary for proper operation of ow meters installed in lined or non-conductive pipes.
Installation Instructions
1. Install the rings upstream and downstream of the meter as shown above.
(Please note that the straight run requirements shown above are only for locating the grounding rings with
respect to the FT-3500 ow meter. The complete straight run requirements for this meter are found in Section
3.1 on page 15 of this manual.)
2. Install each grounding ring sandwiched between (2) ANSI Class 150 anges and (2) gaskets.
3. Center each gasket on the grounding ring surface. Do not allow the gasket to protrude into the ow stream.
4. Use the torque specications provided with the gaskets when tightening the ange bolts.
5. Wire the two grounding rings together as shown and connect them to the ow meter earth wire. Connect this
to a known good earth connection. See Section 3.6.1 on page 29 of this manual for additional information on
identifying an acceptable earth connection.
*