Description; Line Voltage And Fuse Selection - HP 7475A Service Manual

Section I
each plotter. This manual applies directly to plotters
with the serial prefix shown on the title page.
1-12. If the serial number prefix of your plotter is higher
than the one shown, one or more update packages of
revised pages are supplied with the manual. Use these
new pages to replace the original pages. If two or more
update packages are supplied, insert them in order by
revision letter; that is, Revision A first, then Revision B,
etc. The title page will then show the latest serial prefix
and the manual will apply directly to plotters with that
prefix.
1-13. In addition to plotter changes, revised pages may
correct errors in the manual or include improved proce-
dures.
1-14. If the plotter at hand has a lower serial prefix
than the one shown on the title page, information in the
Product History section will adapt this manual to that
plotter.
1-15. DESCRIPTION
1-16. The Model 7475A accepts digital information to
produce graphic plots on ISO A3, 297
X
420 mm
(11 X
17
in.) paper or ISO A4, 210
X
297 mm (8-1/2
X 11
in.) paper
or special transparency plastic. Disposable pens are avail-
able in various ink colors.
1-17. The six-pen capability permits several colors to
be used in a plot without stopping the plotter to change
pens manually. Pens are automatically capped while
they are stored in the pen carousel.
1-18. Seven different line types are provided. Labeling
can be done in nineteen character sets plus user-defined
characters. Text (labeling) can be written in any direction,
upright, or slanted. Character size is also variable. In
addition, arc and circle generation as well as area fill
with various fill types are provided.
1-19. LINE VOLTAGE AND FUSE SELECTION
To prevent damage to the plotter, make
sure the line voltage and fuse selection
is correct before connecting line power.
I
WARN••
I
The line power cord and power outlet
must have a protective earth (ground)
terminal.
1-20. The 7475A primary power circuit can be configured
to operate from any one of the following power sources
at a line frequency of 48 to 66 Hz, single phase. Maxi-
mum power used is 35 W.
1-2
100 Vac-10%, +5%
120 Vac -10%, +5%
220 Vac -10%, +5%
240 Vac -10%, +5%
Model 7475A
1-21. Line voltage selection, and the required fuse
ratings for each line voltage setting, are specified on the
line voltage label which is visible through the small
recessed window in the rear panel. See Figure 1-2.
Applying a line voltage of 220 V or 240 V
to the plotter while the line voltage selec-
tion is set for 100 V or 120 V operation
may damage the plotter circuits.
1-22. The line voltage selection may be changed to con-
form to the line voltage in a particular area. Use the fol-
lowing procedure.
I
WARNING
I
The following procedure should be per-
formed only by service-trained person-
nel who are aware of the electrical shock
hazards involved.
a. Set the plotter LINE switch to OFF
(O)
and dis-
connect the line cord.
b. Remove the plotter top case by removing the
screws indicated in Figure 1-2. Lift the rear of the
top case and the front will then release. When
replacing the top case, make sure the PAPER
HOLD lever extends through the case, and that
the tabs inside the front of the top case align
properly above and below the base plate.
c. Line voltage selection is determined by the power
input connections to the transformer primary wind-
ings. Table 1-2 lists the wire colors and trans-
former contact connections for each line voltage.
The transformer pin numbers are identified on
the power module molding. Figure 1-3 illustrates
the connections for each voltage. Change the wire
connections as required to conform to the desired
line voltage selection.
d.
Make sure the line fuse is correct according to
Table 1-3. The fuseholder cap is the bayonet type.
Press and
turn
counterclockwise to remove, clock-
wise to lock.
e. Change the position of the line voltage label
block so that the voltage selected is right side up.
This block snaps in and out of the power module
molding.
f. Replace the top case, making sure it fits properly
on the front edge of the base and the PAPER
HOLD lever extends through the case.
g. Install the proper power cord for the power range
selected and type of mains outlet to which the
cord is to be connected. See Figure 1-4.