Main Screed Crown Control
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| Illustration 1 | g01390121 |
(1) "B+" from screed circuit breaker (2) Crown switch (3) Right screed control box (4) Crown motor | |
Note: The electrical system on this machine is wired according to the Caterpillar corporate wiring system. In Caterpillar corporate wiring, each wire has a color and a number. Each color and each number has a specific meaning:red wires are positive, black wires are negative and orange wires are in starting circuits. In the numbering system: 100 wires are power circuits, 200 wires are ground, 300 wires are machine basic circuits, 400 wires are monitoring circuits, 500 wires are accessory circuits, 600 wires are lighting circuits and 700 to 999 wires are control circuits
The asphalt paver electrical system provides power to contact "5" of the crown switch through the 119-PK wire.
When the crown switch is in the INCREASE position, the following contacts of the crown switch are closed: contact "1", contact "2", contact "4" and contact "5". Power transfers from contact "4" of the switch to terminal "1" of the crown motor through the H878-OR wire. The ground path from terminal "2" of the crown motor is provided through the H877-BR wire, across contacts "1" and "2" of the crown switch, and through the 200-BK wire.
Extender Height Control
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| Illustration 2 | g01390124 |
(5) Left height switch (6) Left screed control box (7) Left height motor (8) Right height switch (9) Right height motor (10) "B+" from screed circuit breaker (11) Right screed control box | |
The asphalt paver electrical system provides power to contact "5" of the left height switch and the right height switch, through the 119-PK wire.
The left and right extender height switches operate in the same way as the crown switch. An extender is raised when the following contacts of an extender height switch are closed: contact "1", contact "2", contact "4" and contact "5". Also, an extender is lowered when the following contacts of an extender height switch are closed: contact "2", contact "3", contact "5" and contact "6".
Extender Slope Control
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| Illustration 3 | g01390139 |
(12) Left slope switch (13) Left screed control box (14) Left slope motor (15) Right slope switch (16) Right slope motor (17) "B+" from screed circuit breaker (18) Right screed control box | |
The asphalt paver electrical system provides power to contact "5" of the left slope switch and right slope switch through the 119-PK wire.
The left and right extender slope switches operate in the same way as the extender height switches. When the following contacts of an extender slope switch are closed, the corresponding slope motor energizes, and the outboard edge of the extender rises: contact "1", contact "2", contact "4" and contact "5". The outboard edge of the corresponding extender is lowered when the following contacts of an extender slope switch are closed: contact "2", contact "3", contact "5" and contact "6".
Screed Extend Circuit
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| Illustration 4 | g01390157 |
Right screed extend valve (19) is mounted to the right side of the main screed. The left screed extend valve (not shown) is located in the same relative position, only on the left side of the main screed. Each valve contains two solenoids.
The function of each solenoid can be determined by the designation, the number, and color of the power supply wire. The wire designations and solenoid functions are listed as follows:
- K841-BR wire (left extender extend)
- K845-OR wire (left extender retract)
- K842-BU wire (right extender extend)
- K846-PK wire (right extender retract)
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| Illustration 5 | g01390161 |
(20) Extend solenoid (right extender) (21) Arc suppressor (22) Asphalt paver (23) Screed circuit breaker (24) Screed ECM circuit breaker (25) "B+" from main power relay (26) Retract solenoid (right extender) (27) Arc suppressor (28) Wire to asphalt paver ECMs (29) Screed ECM (30) Extend solenoid (left extender) (31) Arc suppressor (32) Retract solenoid (left extender) (33) Arc suppressor (34) Right screed extension switch (right screed box) (35) Right screed extension switch (located on right extender) (36) Left screed extension switch (located on left extender) (37) Left screed extension switch (left screed box) | |
In the screed extend circuit, the screed ECM is completely responsible for monitoring and executing the operator's commands.
In the screed extend circuit, power for the ECM is received from the asphalt paver electrical system at terminal "J1-1" and terminal "J2-1" of the screed ECM. Power for controlling the solenoids is received from the tractor electrical system at terminal "J1-31" and terminal "J1-39" of the screed ECM. System software in the screed ECM reads the input signals coming from the extension switches that are on the screed and on the asphalt paver. As a result, the screed ECM considers all of the information in order to control the extender solenoids.
The left screed extension switches on the screed are monitored by the screed ECM for the EXTEND position at terminal "J2-36" and terminal "J2-47". When any of the left screed extension switches are in the EXTEND position, control power coming from terminal "J2-2" will transfer to contact "1" of the left extend solenoid.
The left screed extension switches on the screed are monitored by the screed ECM for the RETRACT position at terminal "J2-31" and terminal "J2-46". When any of the left screed extension switches are in the RETRACT position, control power coming from terminal "J2-6" will transfer to contact "1" of the left retract solenoid.
The right screed extension switches on the screed are monitored by the screed ECM for the EXTEND position at terminals "J2-38" and "J2-54". When any of the right screed extension switches are in the EXTEND position, control power coming from terminal "J2-5" will transfer to contact "1" of the right extend solenoid.
The right screed extension switches on the screed are monitored by the screed ECM for the RETRACT position at terminals "J2-37" and terminal "J2-55". When any of the right screed extension switches are in the RETRACT position, control power coming from terminal "J2-7" will transfer to contact "1" of the right retract solenoid.
Vibratory Control
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| Illustration 6 | g01390212 |
The extend-a-mat screeds are equipped with four vibratory motors. One motor (39) is located at the inboard side of each extender. Motor (39) is shown on the right extender in Illustration 6. There is an additional motor on the left extender. Also, there is one motor on both of the main screed frames. Each motor turns eccentric weight shaft (38) in order to create the vibration. The vibration makes the screed more effective in compacting the mat.
Electrical Schematic
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| Illustration 7 | g01390216 |
(40) Vibratory speed dial (right screed operator station) (41) Connector "J1" (screed ECM) (42) Screed/paver harness connector (43) Connector "J2" (screed ECM) | |
The vibrator control system is equipped with a vibratory motor speed dial that is located on the right screed operator panel.
Note: The main power switch for the vibrator is mounted on the asphalt paver.
The vibratory motor speed dial is monitored by the screed ECM. The screed ECM is responsible for communicating the position of the vibratory motor speed dial to the machine ECM through the CDL terminal "J1-10" and terminal "J1-20". The machine ECM will control the hydraulic vibratory motors that are located on the screed.
In this circuit, power for the ECM is received from the tractor electrical system at terminal "J1-1" and terminal "J2-1" of the screed ECM. The ECM generates a 5 volt power output signal from terminal "J1-30". Power transfers from this terminal to contact "C" of the vibratory motor speed dial.
The ECM monitors the voltage of the circuit across terminal "J1-30" and terminal "J2-22" in order to determine the position of the vibratory motor speed dial. When the voltage is approximately 1.75, the ECM determines that the vibratory motor speed dial is in the MINIMUM position. When the voltage is approximately 3.25, the ECM determines that the vibratory motor speed dial is in the MAXIMUM position. The dial factor will be linear between these two positions. The dial's minimum and maximum calibration points will be automatically updated whenever the dial value goes beyond the saved minimum and maximum calibration values.
Hydraulic Schematic
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| Illustration 8 | g01390239 |
(44) From vibratory manifold (45) Right vibratory motors (46) To right extender control (tank return) (47) To tamper and vibratory case drains (48) Left vibratory motors (49) To left extender control (tank return) | |
The vibratory manifold is located on the asphalt paver. When the vibratory system is operating, the vibratory manifold directs oil to the vibratory motors on the main screed.
Oil flows through the vibratory motors on the main screed first. The vibrator shaft connects the motors on the main screed together. This mechanical connection causes the motors to rotate at the same speed. When the motors on the main screed are operating at the same speed, an equal amount of oil flows through each motor. Therefore, an equal amount of oil is delivered to the motor on each screed extender, and the motors on the screed extenders turn at the same rate as the motors on the main screed.