This article introduces how the circuit loop of the Doosan DX55-9C excavator works
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The electrical system provides working current to each electrical component through the loop. The
electrical system includes key switches, fuses, fuse boxes, etc. The negative pole of the battery and the
negative pole of the electrical circuit are both connected to the main frame. Even when the key switch is
in the OFF position, the battery still powers the following circuits:
1. Use fuse No. 7/13/14 to supply power to terminal 5 of the CD player, terminal 6 of the wiper motor,
terminal 13 of the wiper controller, terminal CN9-6 of the air conditioning unit, cab lights, and fuel
pump;
2. Supply power to terminal B of the key switch through fuse No. 8;
3. Terminal 1 of the hour meter is powered. When the key switch is turned to the power-on and
starting position, the current passes through the battery, battery switch, U-shaped fuse, fuse box, and the BR
terminal of the starting switch, the battery relay, and activates the coil of the battery relay to connect
the power circuit of the excavator. When the contacts of the battery relay are closed, the current
supplies power to other electronic devices through the battery switch, circuit breaker, and fuse box.
When the engine is not started, the battery supplies power to all electrical equipment, and when the
engine is started, the generator supplies power to the electronic equipment.
