User Manual
ADCP-75-114 • Issue 2C • January 2002
Page 20
©
2002,
ADC
Telecommunications,
Inc.
4 MAINTENANCE
This
section
explains
the
alarm
reporting
system,
provides
a
method
for
isolating
and
troubleshooting
faults,
and
provides
procedures
for
replacing
the
cooling
fan.
The
RIU
requires
no
regular
maintenance
to
insure
continuous
and
satisfactory
operation.
Maintenance,
as
it
applies
to
the
RIU,
primarily
involves
diagnosing
and
correcting
service
problems
as
they
occur.
When
an
alarm
is
reported,
it
will
be
necessary
to
follow
a
systematic
troubleshooting
procedure
to
locate
the
problem.
Once
the
source
of
the
problem
is
isolated,
the
appropriate
corrective
action
can
be
taken
to
resolve
the
problem.
The
only
component
that
can
be
replaced
is
the
cooling
fan.
The
failure
of
any
other
component
within
the
RIU
requires
replacement
of
the
RIU.
4.1 Tools and Materials
The
following
tools
and
materials
are
required
in
order
to
complete
the
procedures
in
this
section:
•
ESD
wrist
strap
•
Small
size
flat-bladed
screwdriver
•
TORX
screwdriver
(T10)
4.2 Fault Detection and Alarm Reporting
Detection
of
a
fault
by
the
RIU
generates
an
external
alarm
response.
An
ALARM
LED
indicator
is
provided
on
the
RIU
front
panel
to
visually
indicate
when
a
fault
is
detected.
In
addition,
normally
open
(NO)
and
normally
closed
(NC)
dry
alarm
contacts
are
provided
to
report
minor
and
major
alarms
to
an
external
alarm
system.
A
minor
alarm
is
defined
as
a
high
temperature
condition.
A
major
alarm
is
defined
as
a
power
amplifier
over/undercurrent
condition.
When
the
RIU
alarm
contacts
are
connected
to
an
external
alarm
system,
detection
of
a
fault
will
generate
an
alarm
at
the
Network
Operations
Center
(NOC).
Whenever
a
problem
is
reported,
refer
to
Table
5
to
isolate
and
correct
the
fault.