ON·BOARD
DIAGNOSTICS
1
PC
INTERFACE
SOFTWARE
Start
off
by
collecting date from the time that
the
engine
is
started.
If
you
have a genset that
has
the idle
mode,
start
the
PC
interface
communicating and data logging before
you
start
the
engine.
If
you
have
an
engine that does
not
have
an
idle
mode,
start
the
PC
Interface
as
soon
as
possible after the
engine
is
running.
Let
the
engine warm
up
for about
10
to
15
minutes
before
trying
to apply an
AC
load. Monitor
and
record
AC
volts
and
amps
if possible.
After
the
engine
is
warmed
up,
start applying
an
AC
load
by
turning
on
various
devices.
Let the unit
run
at each load
change
for
a couple of minutes so that
the
unit
is
stable.
Monitor
and
record
AC
volts
and
amps
if
possible at each
load
site.
Continue
to
as
AC
load until the unit
is
at or near
full
power
rating.
Power
is
determined
by
multiplytng
the
AC
voltage
times
the
AC
amperage. This
will
determine
if
the
unit
is
overloaded or
not.
After
loading
up
the genset, begin
to
reduce
the
1-c
load. Let
the
unit
run
at
each
load
site for a couple of
minli.tes
to
stabilize.
Continue
to
reduce
the
AC
load and monitor
voltage
and
amperage
until there
is
no
AC
load
on
genset.
This
will
give a technician a baseline of what
is
going
on
when
the
engine
is
running under a controlled load condition.
Finally,
after running
the
controlled baseline test,
this
might
sound
strange,
but sometimes the customer might know a
particular
scenario
that
will
cause a problem
for
the
unir.
Sometimes
we
hear customers say that the unit runs
fine
for
awhile
and
when
my
air
conditioner shuts off something
happens.
Try repeating
the
scenario that
the
customer
men-
tions.
Always
start
by
recording date from
the
start
up
for a
least
a
couple
of
minutes
with
no
load on
the
generator
to
get
a starting point. Then continue
to
record data until
the
problem
shows
up.
If
you
have
a
unit
with
no idle mode,
and
the
unit shut
down
under
some
kind of
fault,
the
date
log
will automatically stop
and
save
the
file.
If
you
have a unit
with
an
idle mode,
and
the
unit
was
to
shut
down
under some kind of fault,
you
will
have
to
manually
stop
the
data log
to
save
it.
Or
in
the case of
shutting of
the
DC
circuit breaker, this will
also
cause
the
data
file
to
stop
and
save itself.
WHAT
TO
DO
WITH
THE
DATA
All
of
the
data
that
is
being recorded
is
also
being displayed
on
the
PC
Interface
in
the various boxes. The following
information
applies
whether
you
are looking at
the
data
file
after
it
has
been
recorded
or watching it live
in
the
PC
Interface.
The data
file
can be opened
in
most spreadsheet
software
such
as
Microsoft Excel.
Some
of
the
data
that
is
being collected is pretty
much
self
explanatory
and
simple
to
follow.
For example, I think that
engine
temp,
air
temp,
oil
pressure,
and
battery
volts
would
be
easy
to
figure
out.
Some of the other items may be
less
familiar.
64
Sp,eed
Simple enough,
this
is
the
speed that
the
engine
is
running.
the
genset
is
set
up
to
operate at
60
Hz,
then
the engine
needs
to
run at
1800
rpm
(belt driven units
may
be
different). If
the
unit
is
set
up
for 50
Hz
operation then
the
engine speed
will
be
1500rpm.
When a genset
is
gov~rning
properly,
you
should see
read-
ings
slightly above
and
below
the
desired
speed.
Even
a
well
tuned engine will
vary
a little. The point
is
you
should
see
readings above and below
the
desired speed. If
you
see
speed
readings remain more than
20
rom above or
below
the
desired speed for a prolonged period of
time,
there could
be
a
problem, especially if this
is
noticed with
no
AC
load
applied.
If
the
speed
is
too high
with
no
AC
load applied, check
the
data box labeled Stepper
Pos.
(steps). The throttle
is
con-
trolled
by
a stepper
motor.
Usually
the
step count for
the
engine running with
no
AC
load
is
typically
in
the
20-30
steps range. A couple of steps above or below
this
range
does
not indicate a problem. However, if
the
step
count
is
in
the
single digit numbers or even showing a
zero,
the
problem
maybe
that
the
thrrottle body assembly
may
be out of
calibration or not functioning
properly.
The stepper
motor
can only go
to
a positioin that it thinks
is
zero.
If the
calibration is off,
the
stepper cannot move
the
throttle
closed
enough to slow the engine down.
An
engine that
has
this
problem will run at the proper speed once some
AC
load
has
been
added.
However,
when
that load is dropped, the
speed
will
be
too high, and
in
some cases
may
cause
the
engine
to
over-speed
and
shut down.
If
the
engine speed
is
too
low
with
no
AC
load applied,
there
is
probably a totally different problem.
Again,
look
at
the
Stepper Position.
Is
the
speed low but steps
are
high?
This
would mean that the throttle
is
being opened
to
compensate
for
loss of speed but
the
speed
is
not coming
up.
Check to
make
sure that the fuel level
is
full
in
the
fuel
system
and
that
the
fuel
is
good
and
the
filters
are
clear.
Bleed
the
fuel
system
to
remove
any
air.
Check to make sure that
the
air intake
screens are clean. Check
to
make sure that
the
spark
plugs
have
not fouled.
If
the
engine speed is okay
when
running
with
no
AC
load,
but once underway with some
AC
load being aplied
the
speed drops and stays below the desired
speed,
first
check
the
AC
power
by
multiplying the total
AC
amperage
times
the
AC
volts to get the kilowatts.
If
this
number
is
higher
than
what
the
unit
is
rated
for,
then it
is
overloaded., Shut off
some
of the devices until
the
speed returns
to
normal
and
check the power
again.
If
there is only a small
AC
load
applied and the speed cannot maintain,
follow
the same
suggestions
from
the previous paragraph.
To Next Page
Loading...
