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POWER REQUIREMENTS
The power circuit is electrically isolated providing excellent protection from ground loop faults. The PVmet-500 requires a 10-30VDC,
1.5W power supply. Large wattage supplies can be used.
Reverse input and overcurrent protection are provided on board. Figure 99 shows proper termination of the power connections with
a single point ground.
The supply is fully isolated. The 0V and Earth ground inputs are not connected internally. Earth ground must be connected to
the PVmet-500.
If the incoming power wiring is shielded, the shield connection should be connected at the power supply end only.
The earth connection is critical for protection and noise mitigation. The earth connection should be connected to the common
bonding point within the cabinet the power supply is in.
RS-485 COMMUNICATION S
The PVmet-500uses RS-485 communication because of its reliable nature and its widespread adoption by industry. The RS-485
communication circuit is electrically isolated from the rest of the PVmet-500main board to prevent damage from ground mismatches.
The RS-485 circuit is also hardened against ESD, EMI, DC overvoltage, and AC power line cross using gas discharge tubes and high
voltage current limiting devices. Rs-485 requires three connections for reliable communication shown in Figure 10.
Figure 9: Power connections with a single point ground
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