Rear View Of Screed And Burner Assembly
Figure 33
12VDC SCREED HEATER OPERATION AT
ENGINE IDLE SPEED
12 VDC screed heater system can be put into operation as soon as the paver engine is running at Idle
speed for warm-up. This permits the simultaneous warm-up of both engine and screed in preparation for
paving.
At the end of the paving run when the paver is to be spray cleaned and lubricated with fuel oil, the engine
speed can be reduced to Idle while the screed heater motor is being used to operate the fuel oil pump.
PULSATOR AND COIL
The 12 V.D.C. ignition system for the oil fired screed heater includes a pulsator unit which interrupts the
flow of D.C. current to the ignition coil in order to create a sparking at ignition electrodes. The pulsator is
mounted inside the box which houses the auto. transformer for the right hand vibrators. (See Figure 33)
The ignition coil is mounted on the inner side of the fuel oil pump and fan housing, under the heater
cover. (See Figure 35)
CIRCUIT BREAKER FOR 12 V.D.C. SCREED
HEATER SYSTEM
A burner system power switch on the instrument panel is also the circuit breaker for the system. If the switch
trips to OFF automatically during operation, look for the cause of the overload before re-setting.
A second burner system power switch for ground level accessibility is located on the R.H. junction box for
the screed. (See Figure 33)
A third switch in the screed heater system is described in the following paragraph.
SOLENOID VALVES
Two solenoid operated shut-off valves and a selector switch are used to direct fuel oil flow to burner or to
spray nozzle. A manual shut-off valve is provided in each feed line. They are intended as positive shut- in
case of eventual solenoid valve leakage. Normally they should remain fully open. The toggle type selector
switch has three positions - OFF, BURNER & SPRAYDOWN. (See Figure34)
Right Side View Of Burner
Figure 34
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