Output Wiring Intrinsically Safe | Emerson 2700, 1700 specification

Chapter 5

Output Wiring – Model 1700/2700 Intrinsically

Safe Transmitters

5.1Overview

This chapter explains how to wire outputs for Model 1700 or 2700 transmitters with the intrinsically safe outputs option board (output option code D).

Note: If you do not know what outputs option board is in your transmitter, see Section 1.4.

Intrinsically safe outputs require external power. “External power” means that the terminals must be connected to an independent power supply. The output wiring instructions include power setup and power wiring.

Note: The term “passive” is sometimes used to describe externally powered outputs.

Output wiring requirements depend on whether the transmitter will be installed in a safe area or a hazardous area. This chapter describes several possible configurations:

•Section 5.3 describes wiring requirements for the outputs if the transmitter will be installed in a safe area.

•Section 5.4 describes wiring requirements for the outputs if the transmitter will be installed in a hazardous area.

It is the user’s responsibility to verify that the specific installation meets the local and national safety requirements and electrical codes.

5.2Output terminals and output types

Table 5-1describes the outputs and communication protocols available for the Model 1700 or 2700 intrinsically safe transmitter.

Table 5-1Terminals and output types

Terminals	Model 1700 output type	Model 2700 output type	Communication

1 & 2	Milliamp/Bell 202(1)	Milliamp/Bell 202(1)	HART

3 & 4	Frequency	• Frequency (default)	None
		• Discrete

5 & 6	Not used	Milliamp	None

(1) The Bell 202 signal is superimposed on the mA output.

Note: If you will configure the transmitter to poll an external temperature or pressure device, you must wire the mA output to support HART communications. You may use either HART/analog single-loop wiring or HART multidrop wiring.