AW 375 - Dynamometer Troubleshooting Guide; Common Dynamometer Troubleshooting Issues

SECTION
8
1.
Vibration
2.
Will
not
load
3.
Will
not
unload
4.
Low power
reading
5.
High power
readiqg
6.
Erraticloading
7.
Overheating
8.
Shearing
pins
9.
Damage
to
water
seals,
bellows
or
lid
sasket
10.
Smoke
or
vapor
11.
Unstable
torque
and
power
reading
TROUBLESHOOTII{G
DYI\AMOMETER
Possible
Cduse:
1.
Vibration
A.
Misalignment
B.
Adapter
hookup
C, Lose
shear pins
D.
Damaged
U-Joint
E.
Damaged
Driveline
F.
Dynamic
bearing
problerm
G.
Power
absorption
module
problem
H.
Resonant
vibration
Possible
Renaedy:
A.
Realign
drive
shaft
B.
Check
assembly
for
corroct
fit
and
run
out
C.
Properly
tighten
shear pins
and
use
a
lock
nut
D.
Replace
U-Joint
E.
Replace
drive-line
F.
Determine
cause
and
correct
G.
Change
the
rotation
mass
of
the
prime
mover
or
dynamometer
or
install
a resilient
coupling
Possible
Cause:
2.
Will
Not
Load
A.
Low
on hydraulic
oil
B.
Thermal
fuse
release
C.
Hydraulic
pressure
shut
off
valve
closed
D.
Damaged
hydraulic
line
E.
Defective
chain
or
sprocket
F.
Hydraulic
directional
valve
in
wrons
position
G. Defective
hydraulic
pump
Possible
Remedv:
A.
Fill
to proper
level
with
10
weieht
hydraulic
oil
Replace
thermal
fuse
Section
13.
Refer
to
Section
4
Open
hydraulic
valve
Replace
hydraulic
line
with
original
equipment.
If
unable
to
determine
cause,
consult
factory
for
seryice
Replace
with
new
eomponents
Position
bi-directional
valve
to
proper
direction
G.
Replace
hydraulic
pump
Possible
Cuuse:
3.
Dynamometer
will
not
unload
A.
Defective
control
valve
B.
Defective
dynamic
bearing
C.
Restricted
hydraulic
return
line
D.
Defective
power
absorption
module
Possible
Remedy;
A.
Remove
valve
stem
and
clean
as
required
B.
Determine
cause
and
correct
C.
Find
restriction
and
correct
as
required
D,
Reference
to
SectionIl,12
in
operator
manual.
If
unable
to
B.
D.
E.
F.
I/