Vaisala WMT700 - Manual (Page 86)

User's Guide ______________________________________________________________________
Powering
WMT700 has separate power supply inputs for operating and
heating power. The inputs are usually connected to the same 24
VDC power supply unit, but special applications such as battery
operation or battery back-up may require separate supplies.
The operating power has one supply terminal and one ground
terminal, while the heating power has two supply terminals and
two ground terminals allowing a higher supply current. All supply
ground terminals are internally connected to each other.
NOTE In a system setup with two separate power supplies, avoid ground
potential differences between the supplies. Connect the negative
terminals together if necessary.
Operating Power
WMT700 can use any 9 ... 36 V (nominal voltage 24 V) minimum
2 W DC power supply that meets applicable safety regulations.
Connect heating supply wires to the ground in case heating is not
used. The typical current and power consumptions vs. operating
voltage are shown in Figure 38 and Figure 39 on page 86. Note
that the selected heating option affects the needed operation
voltage when separate powering for operation and heating is used.
Table 26 Operating Power Supply Voltage Requirements
Used Heating Option Operating Power Supply
None 9 … 36 VDC 2 W
Transducers 12 … 36 VDC 2 W
Transducers and arms 14 … 36 VDC 2 W
Transducers, arms and body 16 … 36 VDC 2 W
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