Emerson manual Rosemount 848L, Reference Manual, 00809-0100-4696,Rev AA September

Rosemount 848L

Reference Manual

00809-0100-4696, Rev AA September 2004

Outputs

4 Discrete Outputs

9-32 VDC loads

Maximum load inductance 300 mH

Current Ratings: 1.0 A maximum for single channel on, 4.0 A maximum per device.

Output devices must be selected as follows:

1.Designed to use the same DC voltage as supplied to the 848L I/O power terminals.

2.The DC resistance must be large enough that they consume no more than 1 amp of current steady state. The internal impedance of the 848L is negligible, therefore the Output device’s current is simply calculated as: I/O power / DC resistance.

3.The inductance of the output device must be less than 300 mH.

The maximum total output current for the device will depend on the ambient temperature as shown in Figure A-1.

Figure A-1. Temperature vs. Output Current

	4
(Amps)	3.5
	3
Current
	2.5
Output	2.0
	1.5
Total
	1.0
	0.5
	0
	45	50	55	60	65	70	75
		Ambient Temperature (DegC)

Thermal Shutdown Protection prevents damage to the device if temperature specifications are exceeded.

A-2