Altec Lansing 9444B - Manual (Page 3)

Operating and Service Instructions for the Altec Lancing 9444B Power Amplifier
1 ELECTRICAL
Two amplifier models are
available. One model has a 50/60
Hz power transformer with two
120 V ac primary windings. These
windings may be wired in parallel
or series for operation at either
120 V ac or 220/240 V ac. The ot­
her amplifier model is for export
into countries where the ac line
voltage is 100 volts, 50/60 Hz. The
next two sections refer to the first
model with the dual 120 V ac pri­
mary windings.
1.1 120 V ac, 50/60 Hz
Power Connections
The amplifier is provided
with the primary of the power tra­
nsformer strapped for 120 V ac
operation from the factory. Refer
to Figure 2a for the wiring details.
WARNING: Verify that the power
transformer’s
primary circuit
configuration is correct for the
intended ac line voltage BEFORE
applying power to the amplifier.
1.2 220/240 V ac, 50/60 Hz
Power Connections
The power transformer
has two 120 volt primary windings
which can be connected in paraDel
for 120 V ac line voltages, or in
series to meet 220/240 V ac requi­
rements. Use the following pro­
cedures to re-strap the primary of
the power transformer for 220/240
V ac applications.
1. Make sure the amplifier is
not connected to any po­
wer source.
2. Remove and save the ele­
ven screws securing the
top cover. There are three
screws on each side and
three along the top-rear
edge of the chassis. In
addition, you must remove
the two iimermost screws
inset into the top bumper
strip. Refer to Figure 1 for
the exact screw locations.
Figure 1 Top Cover Removal
3. Locate terminal blocks
TBl and TB2 on the side
of the chassis near the
rear input PC board. Re­
connect the leads as
shown in Figure 2b.
4. Install the top cover with
the eleven screws previ­
ously removed. Two scr­
ews г!ге longer than the
others removed from the
sides and rear. These
longer screws install into
the reeirmost position on
each side of the chassis.
5. Install an 5A fuse, Littel-
fuse Type ЗАВ 5A/250V
slo-blo 326-series ceramic
body or equiv.
2 INSTALLATION
2.1 Rack Mounting
The amplifier ’nay be in­
stalled in a standard 19 inch
equipment rack. It :■ .niires 5V4
inches of vertical rack fipace and
secures to the rack -iibinet with
the four rack mount screws emd
cup washers provided ui the hard­
ware kit.
2.2 Ventilation
The amplifier must be ad­
equately ventilateo ' e, avoid ex­
cessive temperatur- r- ^. It should
not be used in area.' where the
ambient temperature '.xceeds 60
°C (140 °F). To determine the am­
bient air tempera: i. : r, operate the
system in the rack until the temp­
erature stabilizes. Measure the
ambient air with a bull.-type ther­
mometer held at tlie Dottom of the
uppermost amplifier Do not let
the thermometer torich the metal
chassis because the chassis will be
hotter than the ambjent air. If the
ALTEC LANSING* CORPORATION • a Mark IV Company