Trane GRCA - Page 27

PROBLEM PROBABLE CAUSE
SOLUTION
6. Belts mismatched
Belts
improperly tensioned, causing Replace belts and tension drive with slack of
each
a er service more Stretch
ot
some
belts than
others.
belt
on
the
same
Side
ot
the
drive.
7. D rive f ails t
o a d j u s
t
Ol d b elts
a
nd new
b
el t
s use
d
on same drive.
Dif fe
r e
nt
b
ra n
d n ame b
el t
s u se d
o
n same drive.
D river and
d ri
ve
n s
h af t
s s
h if t
ed
f
r o m p a
r
a
l lel.
B elt cor d section damage d duri n g
installation.
Fr et t ing cor r osion ( d rive al l owed t
o
operate
at one speed over a period
o
f t ime).
Replace with new
b
elts.
R eplace with
a se
t
of
M achi n
e
M
a
t
c
h
e
d Belt s.
Realign drive.
R e p
lace
b
elts
and i
nstal l pr
o p
er l y.
Dr ive r p ulley m ust be d isasse m ble d ,
cleaned
and
lubricated, then
r eassembled.
TROUBLESHOOTING GUIDE
DX COOLING
COIL
PROBLEM
PROBABLE CAUSE
SOLUTION
1 . No o r In s uff ic i e nt C oi l
icing.
a.
L ow l i q uid l ine pr essure.*
C
ooli
ng
b . T
her m
a
l expans i
o n
valve.**
c.
Low air flow across
coil.
Air binding.
T her m al ex p ansio n va l ve.**
I ns
u
fficient air flow.
Purge and charge sys
t
e
m.
a.
B ul
b
m ounted
a
t incorrec t l oca t ion.
b. B ul b n o t secure
d p
r oper l y.
a.
See ai r blower
troubles
h oo
tin
g.
b.
Clogged coil
Ai
r bypassing co
il.
Cau
lk
s
afe off.
Undersized system, demand Replace
system.*
exceeding cooling system capacity.
T oo m uch outside
ai r .
R e f rige r an t l
eak.
Check outsid e
a
ir
d
ampers.
Determine leak location and
correct.
Lo w
l iquid
pr
essure. D e t er m i n e cause and co r rec t . *
2. W a
t
e r i n C o n di t io ned
Air E x ceedin g coil f
ace
velocity - 600 fpm . R e d uce uni t a
i r
f
l
o
w.
Dr
a
in pan p - t rap clogge d .
Cl
ea
n p an
a
n
d p -
t rap.
*
Refer to condensing unit installation and service manual.
* `R e f e r to
th
e rm
al
e
x p ansio n va l ve in
s
t al l a t io n i ns tru ction.
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