1.18. PAVING MACHINE ELECTRICAL SYSTEM

TM 5-3895-373-20 1.18. PAVING MACHINE ELECTRICAL SYSTEM. The paving machine electrical system is a 12 VDC system with the exception of a 24 VDC alternator and 24 VDC engine starter. Two 12 VDC wet storage batteries are used in series as the power source. An electronic voltage transformer allows for both the 12 VDC and the 24 VDC to be used without interference. Details of the individual circuits are explained in the following paragraphs. 1.18.1. Electrical System Power Distribution. The paving machine battery supplies 12 VDC to the voltage transformer. From the voltage transformer, this 12 VDC is routed to the 80 amp circuit breaker. Through the 80 amp circuit breaker, 12 VDC is applied to the contacts of the power relay, the horn switch, and to circuit breakers (CB) 8 through 11. The voltage through CB8 is sent to the emergency stop switch on the operator switch panel. From the operator emergency stop switch, the voltage is sent to the emergency stop switches on the screed control panels. With all three emergency stop switches in the normal, pulled out position, the voltage is applied to the ignition switch. In all positions of the ignition switch other than STOP, the voltage is applied to the coil of the power relay (R5). When any of the three emergency stop switches is pushed in, all power to the paving machine is turned off, except to the horn and the work lights. With power relay (R5) energized, 12 VDC is passed through the contacts of the power relay to supply voltage to CBI through CB6 on the operator gauge panel. Power is also supplied to CB11 through CB4 on the left screed control panel and CB 1 through CB3 on the right screed control panel. CB9 through CB11 supply power to the work light switches on the operator gauge panel. 1-22