JLG 600S starter failure case case

Case developer

Case developer: Li Xiaolei;
Business store: GM Xuzhou Store
Case fixed manuscript time: March 15, 2022
 

2. Vehicle information registration

1. Manufacturer: JLG;
2. Equipment type: arm -type high -altitude operating vehicle;
3. Equipment model: 600S
4. Production date: January 2015
5. Working time: 5951H
6. Failure code: No (circuit failure)
7. Weather conditions: good
8. Failure system: Starting the system;
9. Failure phenomenon: no response of the motor after power -on

 

3. fault phenomenon confirmation

Customer reporting equipment cannot be started. After communication, it is confirmed that the use of the machine in the morning is normal. The machine that starts to work in the afternoon can still be launched many times. No pressure drop.

 

4. analysis of the cause

There is no response at the start of the motor when starting, and there may be the following points:
1. [Perhaps fault point 1] Battery losing electricity:
If the battery is not maintained in time, no distilled water is added, the battery plate plate is exposed for a long time, or the battery has been used for too long, the polar plate sulfide, and the performance decreases, etc., will cause the battery failure.
2. [Possible failure point 2] Control circuit failure:
The control circuit is the basic guarantee for starting the motor operation. If the control circuit is not good, the wiring column is rusty, the resistance value is too large, the voltage loss is more, the control relay fails, etc., it will cause the launching motor to move slowly during the start and stop process. Or there is no action.
3. [Perhaps fault point 3] The starter itself fails:
The boot is not maintained during the use of the starter. During the long -term use, the dust of carbon brushing and wear causes the starter's bearings and poorly decelerate gear lubrication. Essence

 

5. Check the disassembly steps

1. [Check and measurement of batteries]: Start the motor no action when starting, and measure the starting motor voltage 12.65V. Because there is no significant voltage drop at startup, it cannot be clearly determined whether the battery is normal. Use emergency function test on site. After testing, the battery voltage drops normal.

2. [Control circuit inspection]: For fault phenomena, check the control circuit according to the circuit diagram, and do not miss any doubts about the doubt circuit joint, wiring box, relay, etc.
In the actual measurement process, no suspicious places were found, and the lines and voltage drops were kept within the scope of standards and acceptable.

2. [Inspection of the starter]: After being inspected and excluded the doubts of the control circuit, the focus is on suspect that there are major problems in the starter itself.

   Disassembled and start the motor shell bolt to start the motor carbon brush damage


3. [Internal inspection of the motor] Due to the damage of the carbon brushing of the motor, it is necessary to open the motivation to make a comprehensive inspection, check the use status of other components, measure the degree of stator and rotor insulation. Brushing damage, causing the starter to lose the startup function.

   
    The carbon gray carbon brush accumulated on the boot reducer is severely worn

 

6. Repair and installation step details

1. [Cleaning the internal pollutants of the starter]: remove and clean the damaged carbon brush particulate matter and wear carbon ash, clean the internal components of the gear to prepare for the assembly;

        
Clean all pollution components to prepare for assembly


   2. [assembly of sponsor parts]: After the detection of the motor, all other components are normal. Only the carbon frame and the carbon brush are damaged. The carbon brush rack has zero loose parts, and it took 38 yuan to buy the required parts for easy installation.

   
The carbon brushing rack and carbon brush for outsourcing are prepared in installation

When assembling, add lubricating fat to the bearings and deceleration gears. After some detection and maintenance, a complete functional boot is reborn. The assembly program can be traveled according to the backpedal of disassembly.

   
   Detection after assembly assembly

After the starting machine failure is eliminated, it is installed on the machine, connects the battery, checks the various oils of the machine, the power -on test machine is normal, and a starter fault is successfully excluded.

7. experience summary refinement

1. [Reminder reminder]:
(1) For electrical appliances and circuits failure, they must not be dismantled at will blindly. You need to measure it with the help of the detection instrument to determine the fault.
(2) Some electrical appliances can be disassembled and interacting accessories after being damaged. There are no scattered parts that can be paired, which can temporarily go to the accessories market to buy emergency;
(3) When checking the electrical appliances and circuit failures, you must use the drawings to view the direction of the line. Do not check the direction of the wrong line, so as not to waste time;

2. 【Experience Summary】:
(1) During the maintenance of the circuit, you must pay attention to safety. First of all, the iron wire should be removed to avoid short circuit damage to other parts and components, causing secondary failure;
(2) When the detection instrument is used, the functional gear must be set correctly to avoid burning the bad instrument;
(3) During the trial check, the absolute safety insurance of electrical appliances and circuits can be started before ignition.

3. [Theoretical basis]: The working principle of starting the motor.