4
LeeBoy Model 8616 Conveyor Paver 4-3
The screed is the last part of the paver that contacts
the paved material. Operation of the screed is usually
done by the screed operator. Paving material is fed
from the hopper and conveyor to the augers to the front
of the screed. The screed has hydraulically controlled
extensions that move in and out to allow a wider paving
base from 8.0 ft up to 15 ft.
Screed heating is accomplished by electric heating
elements mounted directly to the wear plates.
The hydraulically driven vibrators mounted on the main
screed frame can be used to increase paving material
compaction.
The electrical system is powered by one 12-volt battery
mounted in the engine compartment located next to the
generator.
Each battery produces 12 volts DC and maintains 1,260
cold cranking amperes (CCA). An engine-mounted
alternator capable of at least 60 amperes charging
capacity keeps the battery charged during normal
operation. The battery charge rate can be monitored
using the voltmeter on the center operator dash panel.
Electrically heated pavers come equipped with a
generator. The generator is mounted on left side of
paver inside door under hydraulic manifolds.
The generator is hydraulically driven by the load
sense pump on the engine pump stack. When the
paver is at preset engine speed 1400 rpm, and the
hydraulic system is at normal operating temperature,
the generator should operate at a sufcient speed to
produce between 220VAC and 240VAC.
All LeeBoy generators are equipped with an integrated
generator speed control manifold. This manifold should
not require adjustment, but if there is a need to ne tune
the generator speed, there is an adjustment on the
manifold (see Generator Speed Tuning in Section 7).
The paver has heating controls to provide the necessary
connection and control of the output power from the
generator to the heating elements. It is necessary to
maintain all components of the heating controls system
in good working order to maintain safe and efcient
screed heating.
The heating control or distribution/control box is
mounted near the middle of the screed and is easily
accessible to the screed operator when a heating cycle
is required.
There is a ve second delay after the heat cycle is
initiated before the actual electric load is sent to the
heating elements from the generator. This delay is to
allow the generator to reach optimal operating speed
before the electrical load is required.
Once the heat cycle is started, a pre-programmed timer
controls the amount of time for output power from the
generator to go through the element connection supply
plugs coming out of the bottom of the Heating Control
Box to the heating elements.
Any element lead can be plugged into any supply plug
under the heating control/distribution box. All plugs are
equally rated.
Each element is sized to t properly in your screed, and
provide sufcient power to heat your screed plate to a
temperature that mix will not drag or stick to the lower
surface of the screed plate.
To know that the element is correct, you should read
a resistance between 25 ohms and 35 ohms (see
Element Resistance Testing in Section 7).
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