Trane GRCA - Controls and Electrical Connections

PROBLEM
PROBABLE
CAUSE
SOLUTION
1.
Noise
Blower Wheel
a. Loose on
shaft.
b.
Defective blower wheel.
Do not run
blower.
Contact
manufacturer.
c.
Unbalanced.
d.
Worn
as a
result of
contact with
abrasive or
corrosive
material.
Housing
a.
Foreign material in
housing.
b. Cutoff of
other part loose
(rattling
during
operation).
Electrical
a.
Lead-in cable
not secure.
b.
AC hum in
motor or relay
c.
Starting relay chatter.
d.
Noisy motor
bearings.
e.
Single phasing a 3 phase
motor.
Shaft
a.
Bent.
b.
Undersized. May cause
noise
at
blower
wheel, bearings or
pulley.
c.
If more than two
bearings are on a
shaft, they
m
us
t
b
e properly
aligned.
High
Air Velocity
a.
Duct work too small
for application.
b. Blower
selection too
small for
application.
c.
Registers or
grilles too small
for application.
d.
Cooling coil with
insufficient face area for
application.
Obstruction in High
Velocity
Air Stream
a.
Dampers.
may cause
Rattle or Pure
Tone Whistle
b.
Registers.
c.
Grilles.
d. Sharp
elbows.
e. Sudden
expansion in duct
work.
f.
Sudden
contraction in duct
work.
g. Turning vanes.
Pulsation or Surge
a.
Blower too large for
application.
b.
Ducts vibrate at same
frequency as
blower pulsations.
Rattles
and/or Rumbles a.
Vibrating duct work.
b. Vibrating
cabinet parts.
c.
Vibrating parts not
isolated from
building.
2. CFM Low -
Blower
a.
Forward curved blower
wheel
installed backwards.
Insufficient Air Flow
b. Blower
operating backwards.
c.
Cutoff
missing
or
improperly
installed.
d.
Blower wheel RPM too
low.
Duct System
a.
Actual system is
more
restrictive than expected.
b. Dampers
closed.
c.
Registers closed.
d.
Le
a
ks in
supply duct.
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