PS Magazine - TB 43-PS-577
PS, The Preventative Maintenance Monthly
ISSUE 577
DECEMBER 2000
PS 577
49
PS 577
48
DEC 00
id you hear about the AN/PSN-11
precision lightweight global position-
ing receiver that blew up? If you did,
you’re better off than the vehicle op-
erator! When the PLGR blew, he tem-
porarily lost his hearing. The PLGR
was destroyed, of course.
What blew was the PLGR’s 3.6-volt
memory battery. Why it blew was be-
cause the external power source was
hooked up wrong.
PLGR . . .
But this time around the discussion
is about preventing an electrical charge
from finding its way to the memory
battery as a result of the wrong power
or grounding connections.
Step one in the hookup process is to
make sure you don’t reverse polarity
when attaching the PLGR cable to ve-
hicle power. A good way to make sure
advised PLGR users to always remove
the main power battery when connect-
ing the PLGR to external power to
avoid exploding the main power bat-
tery due to a reverse charging situa-
tion. That advice still holds.
You can power The PLGR from an
external power source using cable,
NSN 6150-01-375-8661. But you must
hook up the cable right or you could
lose more than your hearing.
You may remember a Ground Pre-
cautionary Message (GPM 97-005) that
is to remember that the cable wire with
the in-line fuse is always the positive,
or hot wire. It is always connected to a
positive terminal!
Step two is to make sure the PLGR
ground is the same as the vehicle
ground. This can be confusing since
most vehicles have batteries connected
in series.
The PLGR grounding wire should
be attached to the same battery post as
the ground wire that runs from the ve-
hicle to the vehicle’s battery. This
avoids the risk of an inadequate ground
that might occur due to paint or other
insulating affects if you attach the
grounding wire directly to the vehicle’s
body.
In-line
fuse
In-line fuse? Hot wire!
This will work.
..
...but this is better
Hook up power cable right
Remove main power battery
stop!
did you hook
up that cable to
the
external
power right
?
...and
that's
not
all
!
Don’t blow memory battery
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