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remember that instrumentation and other loads grounded directly to the engine block will
not be measured unless their negatives are relocated to the load side of the Battery Shunt.
Special high current shunts are also a solution and may be ordered from us. A separate
engine starting battery whose negative is connected directly to the engine also solves the
problem.
6) We have shown several wires connected to the load side of the battery shunt in the wiring
diagram. If more than a few wires must be connected here, it is best to use a 2/0 jumper
from the shunt to a good negative bus. We recommend that no more than two, or at a
maximum three, connections per large bolt be made on the negative bus side of the shunt.
The negative bus should be a solid copper or brass bar with many threaded screws under
which the negatives for all of the loads may be secured. It should be fed with a conductor
of sufficient size so that there is no appreciable voltage drop even under full load.
WIRE BY WIRE INSTALLATION
Be sure the shunt is installed before proceeding.
The BLACK WIRE (AGND) is the Analog Ground. It is the reference for all measure-
ments. It must be connected on the BSHG (Grounded) side of the shunt. The BSHG side
of the shunt is the side opposite of the negative battery terminals. It must have a good
connection to one of the two #10 screws on the top of the battery shunt.
The RED WIRE (+12 V) is the +12 V supply. (In a 24 V system supply with +24 V.) The
wiring diagram shows two options. The preferred option is to jumper together the RED and
BLUE wires as shown. Wired this way, the meter cannot accidentally be de-powered. It
has the disadvantage of always consuming a little bit of power from the #1 Battery. The meter
consumes about 28 mA (.028 A). If left on all the time it would use about 0.7 Ah per day.
If the system is left on for long periods (long enough to significantly discharge the
battery) with no charging sources then you should consider the option shown with the
dotted line. In this case the RED wire is
not jumped to the BLUE but supplied from the
common of the battery switch. (Be sure to install the 2 A fuse as near the battery switch
as possible.) Whichever battery is selected is the battery that supplies the power. If the
switch is turned off the meter is de-powered. To re-synchronize your meter you must fully
charge the battery when it is put back into service.
The WHITE WIRE (LITE) supplies the display backlighting. It should be supplied from
a switch that controls other instrument lighting. It may be connected to +12 V along with
the RED wire if you wish the lighting to be on all the time. The backlighting consumes about
8 mA (.008 A). If left on all the time it would use less than 0.2 Ah per day.
The BLUE WIRE (B1V) supplies Battery #1 voltage for sensing. It should be supplied
directly from Battery #1. Be sure to install the 2-amp fuse shown in the drawing as near the
battery as possible.