11
2 INSTALLATION
2.5
Wiring
The heavy gauge wires on the BCDC1212T unit carry peak currents of up to 25 Amps, and it is important
to make good, low resistance, electrical connections that will not degrade over time. Failure to make a
good, reliable contact may result in breakdown of the wire insulation and cause a short circuit, or worst
case a fire. We recommend that this activity be undertaken by an appropriately qualified or experienced
person.
The BCDC1212T brown and black wires are fitted with
3
/
16
"
(M5) and
5
⁄
16
"
(M8) lugs respectively for ease
of installation. It is recommended that the BCDC1212T be installed as close as possible to the auxiliary
battery it is charging to minimize cable length and associated voltage drop. Ideally the brown wire should
be connected to the fuse on the auxiliary battery (see Figures 2.7.1 and 2.7.2) without adding additional
length to the brown wire. The BCDC1212T black wire should be connected to a good quality ground. It is
important that all the ground connections of the start battery, auxiliary battery, between the tow vehicle
and trailer, and the BCDC1212T be high quality, have a low impedance between them and be corrosion
free. The red (input) wire can be connected directly to the trailer plug’s +12 V Auxiliary Power pin,
provided that towing harnesses and connectors are suitably rated (see CAUTION in section 2.6)
2.6
Fusing
Fuses must be connected close to the start battery
and the Auxiliary battery in order to protect the wiring
and connectors between the batteries and the BCDC.
REDARC recommends using MIDI style bolt down fuses
as they ensure a low resistance connection. The REDARC
FK23 and FK30 fuse kits are recommended.
Blade type fuses are not recommended as they can
result in a high resistance connection which causes
excess heat and may damage the fuse holder and/or the
wiring.
Self-resetting circuit breakers are not recommended as
they may trip prematurely due to the heat generated by
the current flowing through the wires.
A single fuse and holder setup from the
Fuse Kits are available from REDARC.
Part number FK23 (23 A) or FK30 (30 A).
CAUTION
In applications where the BCDC1212T draws power through the vehicle’s and trailer’s towing harnesses
and connectors, the harnesses wiring gauge, connectors and fuse current ratings and fuse type should be
checked by a suitably qualified person to ensure that it is adequately rated for safe and reliable operation
and that the vehicle’s fuse is appropriately rated and located to protect the wiring in the event of a fault,
including short circuits.
