PREVOST LE MIRAGE XLII BUS SHELLS User Manual

Section 6: ELECTRICAL
PA1553
38
This oil-cooled alternator is self rectifying. All
current carrying members, windings, built-in
diodes, and field coils are stationary. The only
moving component is the rotor. The alternator is
a totally-enclosed unit, cooled and lubricated by
engine oil. The oil inlet is on the diode end
cover. The oil drains back into the engine
crankcase through the drive end frame and drive
adapter housing.
This alternator should never be operated with
the oil supply line disconnected. A continuous
flow of engine oil through the alternator
lubricates the bearings and cools the assembly.
Four terminals are used on this alternator: the
DC output terminal, two field terminals, and a 12
volt relay terminal. The alternator output voltage
is regulated by a separate 24 volt regulator that
controls the alternator field current (Fig. 22 and
23).
CAUTION
The electrical system is NEGATIVE
GROUNDED. Connecting the batteries or a
battery charger with the positive terminal
grounded will endanger the alternator diodes
and vehicle wiring by a high current flow.
Burned wiring harnesses and burned “open”
diodes will result. Always ensure that the
alternator and battery polarities are matched
prior to installation. THE ALTENATOR WILL
NOT REVERSE TO ACCEPT INVERSE
POLARITY. Also, do not ground or short
across any of the alternator or regulator
terminals.
CAUTION
Since there are no brushes, slip rings, or
rubbing seals, the alternator requires no
periodic maintenance other than the following:
1. Check alternator-to-engine mounting bolts
for looseness and tighten to the proper
torque.
2. Check all electrical connections for
tightness and corrosion. Clean and tighten
connections as necessary. Be sure wiring
insulation is in good condition and that all
wiring is securely clipped to prevent
chafing of the insulation.
3. With the engine running, listen for noise
and check the alternator for vibration. If
the alternator is noisy or vibrates
excessively, it should be removed for
inspection and repair.
4. Ensure that battery terminals are clean
and tight
NOTE
The relay coils connected to the alternator
“relay terminal” SHOULD NEVER BE
PROVIDED WITH A SUPPRESSOR DIODE
as the output current at this terminal is not
rectified, thus rendering relay inoperative.
FIGURE 24: CONNECTIONS FOR CHECKING ALTERNATOR OUTPUT 06068
BAD PRACTICE. NEVER JUMP F1 FIELD
TERMINAL TO DC(+) TERMINAL

PREVOST LE MIRAGE XLII BUS SHELLS Specifications

General

Brand	PREVOST
Model	LE MIRAGE XLII BUS SHELLS
Category	Buses
Language	English