Teledyne LXT-280 - Manual (Page 17)

Dissolved Oxygen Transmitter Installation
Teledyne Analytical Instruments 7
Figure 2-2: Intrinsically Safe Wiring Diagram
2.3 Wiring
2.3.1 Site Wiring
Two conduits should be run to the transmitter location, one for
the sensor and the other for the 24 VDC-power source. Proper methods
of terminating the conduit for hazardous locations should be reviewed
by your local plant safety engineer based on State and Federal
requirements.
2.3.2 Power Wiring
For power wiring, the LXT-280 transmitter requires a nominal 24-
VDC voltage source. With zero loop impedance, the minimum voltage
requirement is 14 VDC. The maximum voltage limit is 50 VDC.
Maximum loop impedance at 24 VDC is 450 ohms for the 4-20 mA
compliance. Impedance levels higher than 450 ohms will require
additional DC voltage.
Figure 2-3 illustrates the proper 24 VDC power wiring for the LXT-
280 transmitter. When connecting the power wires, it is important to