Fluke 410B - Overload Protection; Polarity Switching; High Voltage

410B
2-14.
The
meter
in the 410B
has
a
basic
accuracy
of
±2%.
Since multiplying and
shunting
resistors are
used,
the overall accuracy is
approximately
±3%
of
end scale.
However, the accuracy of
the
supply
is ±0. 25%
of the
output
voltage.
For
example, if a
voltage
of 5000
volts
is selected, the output
voltage will be
5000 (±12.
5)
volts
(±0. 25%
of 5000
=
±12.
5).
However, the
panel meter
may
indicate
5000 (±300)
volts
(±3%
of
10,
000
=
±300)
and
still be within
specified accuracy.
Consequently,
the
front panel
controls should be
relied upon
to indi-
cate the
magnitude
of the output
voltage.
2-15. OVERLOAD
PROTECTION
2-16. The 410B
is protected from
damage
due to over-
load by an
overcurrent
trip
circuit. This
circuit will
return
the supply to
standby
operation if
the
output
current
exceeds the
pre-set level.
This
level is inter-
nally
adjustable, and
is usually
set for
12 milliamperes,
but may be adjusted
to lower levels,
down to approxi-
mately 5 milliamperes. If
tripped, the supply
may be
returned to operation by
setting the
HIGH
VOLTAGE
switch to STANDBY-RESET,
waiting 30
seconds for the
time-delay relay
to close, and then setting
the HIGH
VOLTAGE
switch to
ON.
2-17. POLARITY SWITCHING
2-18.
The
output polarity of the
410B
may
be changed
by pulling out
the POLARITY switch
until it reaches the
stop,
rotating the switch to the
desired polarity, and
pushing the
switch
all the way back
to the stop. An
interlock
(S9)
actuated by the
switch
shaft
disables the
instrument when the switch is pulled out. In
order to
return
the
supply to operation, the HIGH
VOLTAGE
switch must be
set
to
STANDBY-RESET. After
30
seconds, when the STANDBY-RESET lamp
illuminates,
set the
HIGH
VOLTAGE switch to
ON.