Specifications

10/31/02 Tech-304/DWO 14195 Page 33 of 39
Appendix D
Grounding Schematic
ICOT SMART
POSITIONER
+
-
TAPE SHIELD &
DRAIN WIRE TO
PREVENT CONTACT
WITH GROUND
SHIELD SHOULD BE
CONNECTED TO THE
SHIELD TERMINATION
POINT OF THE OUTPUT
MODULE OR TO THE
POWER SUPPLY GROUND
TWISTED SHIELDED PAIR
TO HPORT MUX
(HART INTERFACE)
{
PLC OR DCS
4-20 mA
OUTPUT
+
-
SHLD
1
2
3
CONNECTION FROM DCS OR PLC TO POSITIONER IS
20 GAUGE SHIELDED TWISTED PAIR (BELDEN 8762 OR
EQUIVALENT). MAXIMUM DISTANCE IS 5000 FEET.
CONNECTION FROM HART MULTIPLEXER TO POSITIONER
IS 20 GAUGE SHIELDED TWISTED PAIR (BELDEN 8762
OR EQUIVALENT). MAXIMUM DISTANCE FROM HART
MULTIPLEXER TO POSITIONER IS 6000 FEET.
SHIELD SHALL BE CONNECTED TO GROUND AT ONE
POINT ONLY IN ORDER TO AVOID GROUND LOOPS AND
NOISE INTERFERENCE.
THE FOLLOWING TABLE, PER IEEE STD 518-1982, INDICATES
THE MINIMUM DISTANCE BETWEEN CABLE TRAYS AND
CONDUITS CONTAINING LEVEL 1 (THIS INCLUDES 4-20 mA
SIGNALS) AND 120 VAC OR 480 VAC, IN ORDER TO MINIMIZE
ELECTRICAL NOISE INTERFERENCE.
2
3
4.
1
RACEWAY
TRAY
TRAY-CONDUIT
CONDUIT
480 VAC 120 VAC
26
18
12
6
4
3
2