Sensaphone SCADA 3000 Users manual - Manual (Page 56)

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SCADA 3000 User’s Manual
Power Supply
The modules require 10–15VDC to operate. A 14V power supply (labeled AUX PWR) is
provided on the main unit for powering the modules. The AUX PWR terminals are battery-
backed from the main battery connected to the SCADA 3000. Be sure you don’t exceed the
maximum current available from your main power supply. The main board is fused at 4 Amps.
Alternately, you may power the modules from any 10–15VDC power source, but to prevent
data transmission errors be sure to connect the earth ground terminal to a good electrical earth
ground or cold water pipe. (See Figure 1)
Figure 1: Main Unit Power to Modules
Communications Bus Wiring
The modules communicate with the main unit via a 4-wire cable connected to the Bus terminal
block located on the bottom right side of the unit. (See Figure 2)
Figure 2: Bus terminal block
The cable used to connect the modules must be 4-conductor twisted pair with a nominal
impedance of 120Ω (for example, Phonetics part number FGD-0051, Belden 8132 or 9842
cable) and should be routed away from AC cables and power supplies. Use one pair for A &