1. Preheat the suction pipe
There is an air heater in the intake pipe of the Daewoo excavator engine. When the start switch is placed in the preheating position, the current flows through the battery → fuse → B terminal of the start switch → R1 terminal of the start switch → C terminal of the preheat relay → The battery circuit closes the contacts of the preheat relay. When the preheat relay contact is closed, a large current flows through the battery → battery
Relay→Circuit breaker→Preheat relay→Air heater battery, make the heater's heating wire heat for about 19s. After preheating for 19s, the indicator light which indicates that the preheating is completed will light up. When the start switch is placed in the start position, the current flows through the R1 terminal of the start switch to the coil of the preheating relay 6 to continue heating.
2, pre-combustion chamber preheating
Each cylinder block pre-combustion chamber of the engine is equipped with a pre-heating plug. When the start switch is placed in the pre-heating position, the current passes through the battery → fuse → B terminal of the start switch → R terminal of the start switch → C terminal of the preheat relay →Battery, make the contact of the preheating relay connected. When the contacts of the preheating relay are connected, the current flows as battery→battery relay→fuse→preheating relay→preheating plug→battery, and flowing through the preheating plug set on each cylinder block, the preheating time is about 3.5s, There is a timer in the dashboard. After the preheating starts, after 3.5s, the preheating completion indicator light will be on.
When the start switch is placed in the start position, current flows through the R2 terminal of the start switch and the coil of the preheating relay to continue preheating.
