Appendix B: Special Instructions For Class I Division 1 Locations - Emerson FB1200 Instruction Manual

Appendix B: Special Instructions for Class I
1. The Emerson FB1200 flow computer is listed by Underwriters Laboratories (UL) as explosion
proof and is suitable for use in Class I, Division 1, Groups C and D hazardous locations or
nonhazardous locations. Read this appendix carefully before installing an Emerson FB1200
flow computer. Refer to the other chapters of this manual for general information. In the
event of a conflict between the other chapters of this manual and this appendix, always
follow the instructions in this appendix.
2. The Emerson FB1200 flow computer includes both non-incendive and unrated field circuits.
Unless a circuit is specifically identified in this appendix as non-incendive, the circuit is
unrated. Unrated circuits must be wired using wiring methods as specified in Article 501-4(b)
of the National Electrical Code (NEC), NFPA 70 for installations in the United States, or as
specified in Section 18-152 of the Canadian Electrical Code for installation in Canada.
Though the Emerson FB1200 flow computer has a local port for local interrogation, it should
not be accessed with the cover removed in a Class I Division 1 area unless it has first been
verified that no flammable concentrations exist in that area. The local port may be wired
through a conduit, using seals, to an unclassified or Division 2 area.
3. All communication ports terminate on the terminal plate within the enclosure. Wiring to the
connectors is unrated. No connections may be made to communication ports unless the
user ensures that the area is known to be nonhazardous. Connections to the "Local Port" are
temporary and must be short in duration to ensure that flammable concentrations do not
accumulate while it is in use.
4. An RTD may be supplied with the Emerson FB1200 flow computer. Connection to the RTD is
approved as a non-incendive circuit.
Note
A bendable RTD (with a plastic bushing, as utilized in Division 2 installations) may not be
used in a Division 1 area as it renders the area non-explosion proof. Use an RTD connection
head and explosion-proof conduit for Division 1 installations.
5. I/O connections are unrated and must be wired using wiring methods as specified in Article
501-4(b) of the National Electrical Code (NEC), NFPA 70 for installations in the United States, or
as specified in Section 18-152 of the Canadian Electrical Code for installation in Canada.
Special Instruction for Class I Division 1 Locations
Division 1 Locations
DANGER
Emerson FB1200 Flow Computer Instruction Manual
D301782X012
July 2017
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