JL Audio HD900/5 - Manual (Page 6)

6 | JL Audio - HD900/5 Owner’s Manual
Power and turn-on connections
Before installing the amplifier, disconnect the
negative (ground) wire from the vehicle’s battery.
This will prevent accidental damage to the system,
the vehicle and your body during installation.
+12V battery connection
You will need to connect a power wire to
the vehicle’s positive battery terminal, using an
appropriate power ring or specialized battery
terminal connector, such as the JL Audio
XB-BTU. This connection must be tight and
corrosion-free to ensure proper connectivity. This
wire MUST be fused appropriately for safety. Any
positive power wires run through metal barriers
(such as firewalls), must be protected with a high
quality insulating grommet to prevent damage to
the insulation of the wire. Failure to do so may
result in a dangerous short circuit.
Power wire requirements
The HD900/5’s “+12 VDC” and “Ground”
connections are designed to accept 4 AWG
power wire. 4 AWG pure copper wire is
the minimum recommended wire size for
this amplifier. Use of smaller gauge wire
(including cheap wire that is fraudulently sold
as 4 AWG wire) can create a fire hazard.
If you are installing the HD900/5 with other
amplifiers and wish to use a single main power
wire, use 2 AWG or 1/0 AWG pure copper wire
as a main power wire. This 2 AWG or 1/0 AWG
power wire should terminate into a distribution
block mounted as close to the amplifiers as
possible and should connect to the HD900/5
with 4 AWG pure copper power wire, with
each smaller wire fused appropriately for each
amplifier or other electronics in the system.
Please note that lower AWG numbers mean
bigger wire and vice-versa (1/0 AWG is the largest,
2 AWG is smaller, then 4 AWG, then 8 AWG, etc.).
We do not recommend the use of “copper-clad
aluminum wire” or “CCA” wire because this
wire is significantly less conductive than pure
copper wire. Only use pure copper power wire,
such as JL Audio’s MetaWire™. Tinned copper
wire (silver color) is acceptable as the tin-plating
is only a very minor component of the wire.
Fuse requirements
The installation of a fuse on the main power
wire, within 18 wire inches (45 cm) of the positive
battery terminal is vital to protect the wire and
the vehicle from fire in the event of a collision
or short-circuit. The fuse value at each power
wire should be just high enough for all of the
equipment being run from that power wire. Do
not use a fuse with a value that far exceeds the
total fuse rating of the electronics connected to
the wire.
If only the HD900/5 is being run from
a single power wire, install a 60A fuse to
protect the wire: AGU (big glass fuse). AFS
(small blade fuse) or MaxiFuse™ (big plastic-
body fuse) types are recommended.
If other amplifiers are also being powered from
a main power wire and exceed 80 amps in total
fuse rating, we recommend the use of an ANL
(large-blade) fuse and holder. Each amplifier can
then be fused independently at the outputs of
the power distribution block. Use JL Audio part
XC-FOA-2PAK and appropriate MaxiFuse™ type
fuses with JL Audio distribution blocks.
Please consult with your JL Audio
dealer to make sure that the wire, fuse
holder and fuse ratings are appropriate
for your system’s needs. The safety of
your installation depends on appropriate
power connections and fuse protection.
ground connection
The chassis ground connection must be made
using 4 AWG pure copper wire and should be
kept as short as possible, while accessing a solid
piece of sheet metal in the vehicle. The surface of
the sheet metal should be sanded at the contact
point to create a clean, metal-to-metal connection
between the chassis and the termination of the
ground wire with a brass or copper power ring.