RADIO FREQUENCY INTERFERENCE
WIRING REQUIREMENTS
Refer to
Appendix A
for detailed information about position trans-
mitters.
NOTE: Route the wiring inside the positioner so it does not
become entangled with moving parts. A cable clamp (Fig.
4-1) is provided inside the positioner so entanglement can be
avoided.
3. Grounding positioners should be done in accordance with
local electrical codes (in U.S, National Electrical Code, ANSI/
NFPA 70. In Canada, Canadian Electrical Code, CSA c22.1). A
grounding screw is provided inside the enclosure for grounding,
denoted by
.
NOTES:
1.
The grounding screw located inside the enclosure is a safety
ground and should not be used to ground the shielded pair.
2.
The positioner must be grounded to avoid ground loop
conditions.
Most electronic equipment is influenced by radio frequency inter-
ference (RFI). Caution should be exercised with regard to the use
of portable communications equipment in the area.
ABB recommends posting appropriate signs in the plant. Refer to
the Site Planning and Preparation instruction for additional infor-
mation on RFI.
Under ideal conditions, the use of conduit and shielded wire may
not be required. However, to avoid noise problems, it is recom-
mended that wiring be enclosed in conduit. Just prior to entering
the housing, rigid conduit should be terminated and a short length
of flexible conduit should be installed to reduce any stress.
INSTALLATION
RADIO FREQUENCY INTERFERENCE
3-1
or
3 - 15