PS Magazine - TB 43-PS-710

PS, The Preventative Maintenance Monthly

ISSUE 710

JANUARY 2012
PS Magazine - TB 43-PS-710 - Page 4 of 33
4
PS 710
JAN 12
The EMU collects engine operational data that
plays a vital role in condition-based maintenance
(CBM), the Army’s new maintenance system for
depots. When the engine is returned to the depot,
having this historical EMU data makes the over-
haul and rebuild process easier and more cost
effective. If the EMU data is missing or incomplete,
your
engine
doesn’t
get
all
the
maintenance
attention it needs.
The key to the whole process is the power
interface box (PIB). The PIB is located in the engine
compartment
just
forward
of
the
powerpack’s
quick-disconnect panel. It comes equipped with
two circuit breaker toggle switches numbered 1
and 2. Circuit breaker #1 is used to provide power
for the EMU. Circuit breaker #2 is a spare for
future use.
Far too often, these circuit breakers are found in the OFF position. Why? It’s a bit
of a mystery, but there are a few possibilities:
•± Vehicle±electrical±system±faults±could±be±causing±the±circuit±breaker±to±trip.
•± Sidecar±failure±has±been±known±to±trip±other±circuit±breakers±in±the±tank’s±electrical±
system.±So±it’s±possible±that±this±circuit±breaker±is±being±tripped±by±the±sidecar.
•± Intentionally±flipping±the±circuit±breaker±to±OFF.±Some±mechanics±and±tankers±believe±
the±EMU±is±a±spy±device.±That’s±simply±not±true!±Turning±the±circuit±breaker±off±
just±means±the±operational±wear±and±tear±on±your±engine±isn’t±properly±recorded,±
hindering±the±CBM±process.
•± Ignoring±the±position±of±the±switches.±Some±tankers±and±mechanics±think±the±
protective±covers±force±the±switch±to±the±ON±position.±Unfortunately,±that’s±not±the±
case.±So±make±sure±the±switch±is±in±the±ON±position±before±closing±the±cover.
A redesign of the red protective circuit breaker covers is under development. If
implemented, the new covers would force the switch to the ON position when closed.
But until that redesign is applied, it’s your responsibility to make sure the circuit
breakers are on.
T
he±M1-series±tank’s±transmission±filler±neck±doesn’t±
have± a± very± big± opening,± mechanics.± In± fact,± it’s± so±
small,±you’ll±end±up±with±a±lot±of±spillage±if±you±try±to±
pour±transmission±fluid±directly±from±a±can.
± The±spilled±fluid±blows±onto±the±oil±cooler±fins±where±
it±attracts±dirt±and±dust±like±a±magnet.±That±gooey±mess±
won’t±let±the±heat±radiate±away±from±the±oil±inside±the±
coolers,±putting±your±transmission±at±risk.
± Stop±the±spillage±by±inserting±a±1-qt±flexible±funnel,±
NSN± 7240-00-559-7364,± in± the± filler± neck.± Just± slowly±
pour±the±fluid±into±the±funnel±to±prevent±overflow.
Flexible±funnel±
prevents±oil±
spills
EMU loses power with circuit breaker 1 in OFF position
PIB
Circuit
Breaker
On?
M1-Series Tanks…
PIB
Circuit
Breaker
On?
Oil Spill
Damages
Transmission
The engine memory unit
(EMU) on your M1-series tank
plays an
important
role,
tankers and mechanics.
We gotta get
a move on!
We’re running
late
for
that training
exercise!
Don’t worry.
I’ll get us
there
fast!
we’d better
turn oFf the pIB
circuit Breaker
FirSt!
the depot
will NeEd
that data
for my next
Rebuild!
c’mOn,
guys!
You don’t
wanna do
that!
710 04-05.indd
1-2
12/6/11
1:59 PM
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