Vaisala hmt120 - Figure 12 Isolated Current Loop Wiring; Table 4 Wiring Table; Wiring

3.8.1 Wiring
1 SHLD
2 CH1-
3 CH1+
4 CH2-
5 CH2+
mA
mA
-
+
-
+
10 ... 30 VDC
10 ... 30 VDC
Figure 12 Isolated Current Loop Wiring
Table 4 Wiring Table
Terminal
1)
Current Output (2-Wire, CH2 Isolated)
1 Cable shield (optional)
2 CH1- (signal and power supply -)
3 CH1+ (signal and power supply +)
4 CH2- (signal and power supply -)
5 CH2+ (signal and power supply +)
1) Terminal numbers 1 ... 5 in the first column of the wiring table refer to Figure 12 (page 22)
To connect the wiring:
1. Remove the transmitter cover as instructed in Opening the Transmitter Cover (page 13).
2. Insert the signal wires through the selected cable gland/conduit
fitting in the bottom of
the transmitter or alternatively through the rubber grommet at the back side of the
transmitter.
3. Connect the wires as instructed in Figure 12 (page 22) and Table 4 (page 22). Suitable
wire size is 0.5 ... 1.5 mm
2
.
If an isolated output is required with current outputs, both channels require
their own power supply. CH1 must always be powered because CH1 is the
main output, and the transmitter will not operate if only CH2 is connected.
4. Close the cover by keeping it slightly tilted and first attaching it to the fixing snaps at the
top of the enclosure base and then pushing the lower part of the cover firmly forward
until it locks. The transmitter is ready for use.
HMT120 User Guide M211244EN-C
22