Table of Contents
Advertisement
INSTRUCTION
MANUAL
Digital Mullimeter
Models
172A.
173A
MAINTENANCE
6-8.
FUSE REPLACEMENT.
With
the
exception
of
the
current
fuse,
all
fuses
are
located
internally
in
the
Model
172A/l73A.
To replace
the
current
fuse,
proceed
to
step
g.
To replace
an internal
fuse,
proceed
as follows:
\,
WARN I NG
Disconnect
the
line
cord
before
removing
the
case
cover
2
Turn
off
power
and disconnect
the
line
cord.
b.
Turn
the
DMM bottom
side
up and
loosen
the
four
screws
in
the
bottom
cover.
These
screws
are
held
captive
by rubber
O-rings..
c.
Hold
the
top
and bottom
covers
together
to prevent
their
separation
and turn
thrDMM
over
to
normal
position.
&
Lift
off
the
top
cover.
e.
Replacement
of
Battery
Pack fuses.
F401,
F402 and F403.
I)
Leave
the
Battery
pack
in place
and connected.
2)
Remove either
F401,
F402 or
F403
(shown
in Figure
2-2)
and replace
it
with
a IA,
25OV,
3AG SLO-BLO fuse
(Keithley
part
number
FU-IO).
3)
Reinstall
top
cover.
f.
Replacement
of
Line
Fuse
FOOI.
I)
Once the
top
cover
is
removed,
FOOI is accessible
without
removing
any
other
components.
2)
Remove FOOI , shown
Figure
6-2,
and
replace
it
with
a 1/4A,
25OV.
3AG
SLO-BLO fuse
(Keithley
part
number
FU-17)
for
117V line
operation,
or
a 1/8A,
25OV,
3AG SLO-BLO fuse
(Keithley
part
number
FU-20)
for
230V
line
operation.
3)
Reinstall
top
cover.
9.
Curr="t
Fuse
F501.
I)
The current
fuses in accessible
from
the
rear
panel
as shown
in
Figure
2-I.
2)
Replace
F501 as follows:
Model
l73A:
3A, 25ov,
3AG (Keithley
#FU-2).
Model
172A:
2A,
25oV,
3AG (Keithley
#FU-13).
n !
CAUTION
Do not
install
fuses
with
higher
ratings
than
specified.
Instrument
damage may cxcur.
6-21/2:
Advertisement
Table of Contents
