Campbell Scientific CR10X Measurement and Control System - Manual (Page 222)

SECTION 14. INSTALLATION AND MAINTENANCE
14-6
14.5 DIRECT BATTERY CONNECTION
TO THE CR10X WIRING PANEL
For some applications, size restrictions or other
operational considerations may preclude the use
of Campbell Scientific power supply options. In
these cases the power supply may be connected
directly to the wiring panel. Any 9.6 to 18 VDC
supply may be connected to the 12 V and G
terminals on the wiring panel. The metal
surfaces of the wiring panel and mounting
bracket are at power ground. Make connections
to the wiring panel first and then to the power
supply. If the power supply must be connected
first, connect the positive to the wiring panel
before the ground to avoid shorting to the wiring
panel or mounting bracket.
14.6 VEHICLE POWER SUPPLY
CONNECTIONS
If a CR10X is to be powered from the 12 Volts
of a motor vehicle, a second 12 V supply is also
required at the time of vehicle start-up. When
the starting motor of a vehicle with a 12 V
electrical system is engaged, the voltage drops
considerably below the nominal 12 V, which
would cause the CR10X to malfunction every
time the vehicle is started. The second 12 V
supply prevents this malfunction. Figure 14.6-1
shows the general case for connecting the two
supplies to the Wiring Panel. The diode allows
the vehicle to power the CR10X without the
second supply attempting to power the vehicle.
To reduce the potential for ground reference
errors in measurements, the ground lead should
be 16 AWG or larger.
FIGURE 14.6-1. Connecting to Vehicle Power Supply