TM5-6625-2694-13&P
Table
5-1.
Direct
Support
Troubleshooting
(cont'd.)
MALFUNCTION
TEST
OR
INSPECTION
CORRECTIVE
ACTION
ONE
OR
TWO
FAN
MOTORS
DO
NOT
RUN.
Step
1.
does
not
run
and
associated
Check
Fan
Motor(s)
that
components.
Fan M o t o r
at
voltage
a.
Check
leads
to
across
Terminal
15
(+)
to
terminal
terminal
strip.
16
(-)
should
be
24
VDC.
b.
Refer
to
5-7
and replace Fan Motor(s)
if
24
VDC
is
present and
Fan
Motor(s) does not run.
with
Rectifier
Bridge(s)
associated
Fan
Step
2.
Check
Motor(s)
that does not run.
-
terminal
Measure
voltage
a.
across + terminal
and
be
24
VDC.
Rectifier
Bridge;
should
Measure
on
voltage
across
AC
terminals;
should
be
24
VAC.
Refer
to
b.
and
replace
Rectifier(s)
if 24 VAC is present across AC
terminals and
0
VDC
is
present across + terminal and -
terminal.
with
Fan
Step
3.
24
V.
Transformer(s)
Check
associated
Motor(s).
terminal
a.
Measure
voltage
output
5
and
terminal
6
of
associated
Transformer(s); should
be
24
VAC.
Measure
terminal
b.
input
1
and
voltage
across
terminal
4
of
Transformer(s).
With
associated
input
Selector
Voltage
Plug
in
LO
position
With
Voltage
Selector
measurement should be 120 VAC
.
position, m
easurement should be
Plug in HI input
240
VAC.
to p a r a g r a p h 5 - 1 5 a n d
c.
Refer
replace
Transformer(s)
if
input
voltage
is
correct
and
output
is
NOT
24
VAC.
5-4 C h a n g e
1