Teledyne LXT-280 - Manual (Page 18)

Installation LXT-280
Teledyne Analytical Instruments 8
observe the polarity. Although no damage to the LXT-280 will result
from polarity reversal, the instrument will not function.
For intrinsically safe wiring see Figure 2-2.
CAUTION: DO NOT APPLY 110 VAC TO THE 24 VDC WIRING
TERMINALS. DAMAGE TO THE INSTRUMENT WILL
RESULT!
2.3.3 Sensor Wiring
A conditioned input is required from the sensor or electrode to the
LXT-280 transmitter for proper operation. Teledyne models SP-1 and SP-
2 sensors will provide the required conditioning. Figure 2-3 illustrates the
proper wiring of the sensor to the LXT-280 transmitter.
Figure 2-3: LXT-280 Wiring
2.3.4 DC Power
The LXT-280 requires an external 24 VDC power source to
operate. With zero loop impedance, the minimum voltage requirement is
13.5 VDC. The maximum voltage limit is 50 VDC. Maximum loop
impedance at 24 VDC is 525 ohms for the 4-20 mA compliance.
Impedance levels higher than 525 ohms will require additional DC
voltage.