Emerson Process Management MMI-20020979 Carbon Monoxide Alarm User Manual


 
3 Wiring
Topics covered in this chapter:
Available output terminals and wiring requirements
Hazardous area output wiring
3.1 Available output terminals and wiring
requirements
Three pairs of wiring terminals are available for transmitter outputs. These outputs vary
depending on your transmitter output option ordered. The Analog (mA), Time Period
Signal (TPS), and Discrete (DO) outputs require external power, and must be connected to
an independent 24 VDC power supply.
The screw connectors for each output terminal accept a maximum wire size of 14 AWG
(2.5 mm
2
).
Important
Output wiring requirements depend on the hazardous area classification of the environment
in which the meter is installed. It is your responsibility to verify that this installation meets all
corporate, local, and national safety requirements and electrical codes.
If you will configure the meter to poll an external temperature or pressure device, you must
wire the mA output to support HART communications. You may use either HART/mA single-
loop wiring or HART multi-drop wiring.
Transmitter outputsTable 3-1:
Transmitter version
Output channels
A B C
Analog 4–20 mA + HART 4–20 mA Modbus/RS-485
Time period signal (TPS) 4–20 mA + HART Time Period Sig-
nal (TPS)
Modbus/RS-485
Fixed 4–20 mA (tem-
perature)
Time period sig-
nal (TPS)
Disabled
3.2 Hazardous area output wiring
Micro Motion provides safety barrier and galvanic isolator installation kits for wiring the
meter in a hazardous environment. These kits provide the appropriate barriers or isolators
depending on the outputs available and approvals required.
Wiring
Installation Manual 23