stops at a set of traffic lights or a rest area,
the alternator output is about 70 amps
at idle, which implies that the batteries
are discharging to assist the alternator in
providing power to the system.
Upon arriving at Mt Isa, the battery may be
further discharged, at times to less than 10.5
volts. A deeply discharged battery (below
11.9 volts) may not start a truck or potentially
may even damage the starter motor because
the starter motor does not get the required
voltage to engage or disengage correctly.
The costs to maintain an adequately rated
electrical system are minor when compared
to downtime, loss of contracts, penalties and
component replacement.
To ensure the correct alternator is fitted to
the application:
- Assess the electrical accessories on your
truck (see Table 1)
- Ensure the alternator output (amps) at
operating temperature is able to cover all
the electrical loads of the vehicle. The type
and the rating of the alternator you need
will depend on the nature of your transport
application and the amount of time your
engine idles- It is important to note that ensuring the
alternator will provide high output at low
rpm is critical to exceeding the electrical
load requirements found in modern
vehicles fitted with aftermarket accessories
and options.Prestolite IdlePro
PACCAR Parts recently added the new
Prestolite IdlePro range of alternators to its
distribution network.
“We are seeing a number of new and
older vehicles that have higher electrical
loads due to the nature of their application,
upgrading to these high-quality alternators,”
Mohan says.
“ The IdlePro alternators deliver industry
best output at low engine speeds (63 per cent
efficiency at idle) thus reducing loads placed
on the batteries and also reducing wear and
tear on starter motors. We want to educate
more customers on upgrading the electrical
systems, to ensure a balanced and reliable
charging system.”
Figures 1 and 2 compare the performance
curve of various alternators at 650 rpm and
1,450 rpm. This output is measured at normal
under bonnet operating temperature.
The IdlePro series alternators support
electrical systems and engine performance
through their various features that help
DEALS Showcase
extend battery life andincreasevehicle
uptime. They are availablein170,190, 210
and 240 amp rating withbothJ180hinge
mount and pad mount.Theycomewith
a warranty of two years/500,000km
(conditions apply).
IdlePro alternators canbepurchased
at 57 PACCAR Parts andTRPdealerships
across Australia and NZ.Supportedby
skilled technical productassistancestaff,
the PACCAR Parts dealershipnetworkwill
support customers promptlyandefficiently.Look out for a price promotiononthe
IdlePro alternators inthePACCARParts
July-August catalogue.Formoreinfoor
to enquire on stock availability,please
contact your local dealerorvisit
http://www.paccarparts.com.au/find-a-dealer.PACCARPartswouldlike
tothankPrestoliteElectric
andCenturyYuasafor
theirtechnicaladviceand
contributiontothisarticle.Figure 1:
Figure 2:
Thischartassumesa 3:1alternatorpulleytocrankratio.This chart assumes a 3:1 alternator pulley to crank ratio.183