Emerson Process Management 2090 manual Field Wiring, Rosemount 2088 and, Reference Manual

Rosemount 2088 and 2090

Reference Manual

00809-0100-4690, Rev EA March 2007

Figure 3-9. Transmitter

Load Limitations

LOAD (OHMS)

Max. Load = 45.4 (Power Supply Voltage) –10.5

1158

1000

800

600

400				Operating
200				Region
0
					30(1)
	10.5	15	20	25		36

POWER SUPPLY (DC VOLTS)

(1) For CENLEC EX ia Approval, power supply must not exceed 30 volts.

NOTE

Minimum load impedance for Output Code N is 100 kilohms.

Field Wiring

All power to the transmitter is supplied over the signal wiring. Signal wiring need not be shielded, but use twisted pairs for best results. Do not run unshielded signal wiring in conduit or open trays with power wiring, or near heavy electrical equipment. For high EMI/RFI environments, shielded twisted pair cable should be used. To power the transmitter, connect the positive power lead to the terminal marked “PWR/COMM+” and the negative power lead to the terminal marked “–” (see Figure 3-10). Tighten the terminal screws to ensure that proper contact is made. Avoid contact with the leads and the terminals. No additional power wiring is required for transmitters with

4-20 mA output. For low power transmitters, connect positive signal lead to “test +” and negative signal lead to terminal marked “-.”

To connect test equipment for monitoring the output of the Rosemount 2088 Smart during maintenance procedures, connect one lead to the terminal labeled “TEST+” and the other lead to the terminal labeled “–” (see Figure 3-10). Avoid contact with the leads and the terminals.

Signal wiring may be grounded at any one point on the measurement loop, or it may be left ungrounded. The negative side of the power supply is a recommended grounding point. The transmitter case may be grounded or left ungrounded.

Conduit connections at the transmitter should be sealed to prevent moisture accumulating in the field terminal side of the transmitter housing. Also, install wiring with a drip loop with the bottom of the drip loop lower than the conduit connection of the transmitter housing.

3-12