Emerson manual Wiring, Power Supply Connections, Rosemount 848L, Reference Manual

Rosemount 848L

Reference Manual

00809-0100-4696, Rev AA September 2004

WIRING

Figure 2-3. 848L Transmitter Fieldbus Wiring

Power Supply

Connections

If the device or sensors are installed in a high-voltage environment and a fault condition or installation error occurs, the sensor leads and transmitter terminals could carry lethal voltages. Use extreme caution when making contact with the leads and terminals.

NOTE

Do not apply high voltage (e.g. AC line voltage) to the transmitter bus or I/O power terminals. Abnormally high voltage can damage the unit (bus and I/O power terminals are rated to 42.4 VDC).

	6234 ft (1900 m) max
	(depending upon cable
Integrated Power	characteristics)
Conditioner	Terminators
and Filter
	(Trunk)
Power
Supply		(Spur)
	(Spur)
FOUNDATION		Signal
		Wiring
fieldbus Host or			01A848-848
configuration tool
	Devices 1 through 16*

The transmitter requires both a fieldbus connection and power for the discrete I/O channels.

Fieldbus Connection

The fieldbus connection requires between 9 and 32VDC to operate the electronics. The dc power supply should provide power with less than 2% ripple. A fieldbus segment requires a power conditioner to isolate the power supply filter and decouple the segment from other segments attached to the same power supply. Signal wiring should be shielded, twisted pair for best results in electrically noisy environments. Do not use unshielded signal wiring in open trays with power wiring or near heavy electrical equipment. Use ordinary copper wire of sufficient size to ensure that the voltage across the bus terminals does not go below 9 VDC. The power terminals are not polarity sensitive. To power the electronics and establish communications:

1.Connect the fieldbus wires to the terminals marked "Bus" as shown in Figure 2-4 on page 2-5.

2.Tighten the terminal screws to ensure adequate contact.

2-4