User's Manual

Trailblazer Installation and User Manual version 1.03
10
Figure 2: Base Unit Power Connections
If you are not using the CWT power supply, size your power supply adequately using
Ohm’s law. For example, if you provide 12VDC you consume 2/12 A or about 167mA. If
you provide 24VDC you use about half of that or 85mA. CWT recommends providing at
least 4 times the power consumption. The Trailblazer consumes 2 Watts. CWT’s power
supply with battery backup supplies 13.8VDC @ 1 A or 14 Watts.
You can also power your Trailblazer by using several of the unused voice/data pairs in a
standard 6 pair telephone cable. Don’t forget to allow for additional current if add-on
card options are selected.
The standard 6 pair telephone cable is made of 22 AWG size copper. This means that
both legs will have 3.2 ohms of resistance per 100 feet. The table below shows the
distance at which you have a 5% maximum recommended voltage drop using 2 pairs of
wires paralleled together.
Positive
12 to 24 VDC
Negative
(Normally earth ground)
Terminal Block