6 MG310-en-GB_V1.0 12/15
INSULATION
RESISTANCE
MEASUREMENTS
1.
Select
the
desired
test
voltage
using
the
rotary
function
switch.
Select
the
250V,
500V,
or
1000V
switch
position
for
the
corresponding
output
test
voltage.
2.
Connect
the
red
test
lead
to
the
meter’s
LINE
(4)
jack
and
the
black
test
lead
to
the
EARTH
(1)
jack.
Connect
the
probe
end
of
the
test
leads
to
the
circuit
under
test.
3.
Press
the
TEST
button
to
test.
The
button
will
self
‐
lock
and
the
button
lamp
will
light.
Note:
If
the
circuit
under
test
is
live
and
has
a
voltage
potential
(AC/DC)
over
30V,
the
meter
will
not
test
(the
display
will
show
the
“>”
icon
and
the
symbol
will
flash;
the
buzzer
will
also
sound).
If
the
circuit
under
test
is
not
live
or
if
its
voltage
is
less
than
30V,
the
meter
will
begin
applying
high
‐
voltage
to
the
circuit
under
test.
4.
The
primary
display
will
show
the
insulation
resistance
in
M
Ω
(megaohms)
or
G
Ω
(gigaohms).
5.
The
test
voltage
(VDC)
value
will
be
indicated
in
the
right
‐
most
auxiliary
display,
the
symbol
will
flash
and
the
caution
buzzer
will
sound.
6.
Press
to
release
the
TEST
button
to
stop
the
test.
The
high
voltage
will
switch
off
and
the
resistance
value
indicated
in
the
primary
display
will
hold.
7.
Subsequently,
the
meter
will
internally
discharge
the
balance
of
the
insulation
test
voltage.
Note:
Turning
the
function
switch
to
another
test
position
will
abort
the
test.
8.
A
reading
of
>5.50
G
Ω
indicates
that
the
meter
reading
is
above
the
resistance
threshold
of
that
measurement
range.
CAUTION
Before
taking
measurements
disconnect
the
unit
under
test
from
all
power
sources
and
isolate
it
from
any
stray
resistance.
Do
not
short
circuit
the
test
leads
when
voltage
is
output
from
the
meter.
Allow
sufficient
time
between
tests
for
devices
under
test
to
stabilize.
When
red
and
black
clips
are
connected
to
the
circuit
under
test,
high
voltage
is
output
from
the
LINE
jack
and
current
from
the
EARTH
jack.
At
the
completion
of
a
test,
do
not
touch
any
parts
of
the
circuit
under
test.
Components
may
have
become
charged
during
the
test
and
could
discharge
when
touched.