beautypg.com

Power supply, Communications bus wiring, Power supply -2 communications bus wiring -2 – Sensaphone SCADA 3000 Users manual User Manual

Page 56

background image

7-2

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 &