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J2108A circuit common fault

Feb 09, 2019 Leave a message

J2108A circuit common fault

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There are three main reasons for common faults in the J2108A circuit. One is the electrical fault caused by mechanical failure; the second is the fault of the electrical itself; the third is the electrical fault caused by the change of the ambient temperature and humidity. The main electrical faults of the J2108A offset press are now analyzed as follows:


Fault 1: The motor does not start.

Failure analysis:

1.The power supply is not connected;

2. The winding is open; 

3. The stator winding is short-circuited; 

4. The stator winding is grounded; 

5. The phase is missing.


Troubleshooting:

1.Check the switch, fuse, each contact and motor lead-out line;

2. Check the open circuit to eliminate the fault; 

3. Check the short-circuit and eliminate the fault; 

4. Measure the resistance of the motor to ground with a megohmmeter, not less than 0.5MΩ. Check incoming power and fuses.


Fault 2: The motor is overheated.

Failure analysis:

1.The power supply voltage is too high or too low;

2. The stator phase-to-phase short circuit; 

3. The three-phase power supply or the stator winding one of the phases is open; 

4. The overload; 

5. The ambient temperature is too high or the ventilation is not smooth.

Troubleshooting:

1.Check the three-phase power supply;

2. Check the three-phase power supply and current stator phase and ground insulation resistance; 

3. Check the supply voltage and fuse and phase current; 

4. Check the load current; 

5. Check the ambient temperature and ventilation holes .


Fault three: slip clutch insulation breakdown

Failure analysis:

1.Insulation is damp;

2. Heating, generating eddy current; 

3. Input voltage exceeds rated value.

Troubleshooting:

1.Check the ambient temperature;

2. Check the load current; 

3. Check the output voltage of the electromagnetic speed controller (0-90V) and replace it after troubleshooting.


Fault 4: The speed of the car is unstable.

Failure analysis:

1.The speed of the speed measuring generator is unstable;

2. The three-phase winding of the speed measuring generator has a phase disconnection, the brush has poor contact, and the bearing wears large; 

3. The speed measuring generator bearing is stuck and damp;

4. The electromagnetic speed controller has malfunction.


Troubleshooting:

1.Check that the three-phase output voltage of the tachogenerator should be balanced and there should be no fluctuations;

2. Check that the three-phase winding value should be symmetrical, whether the bearing is normal, whether the brush is in good contact;

3. Check the bearing and check the ambient temperature; 

4. Check Electromagnetic speed controller components.


Fault 5: The control circuit is turned on and the fuse is broken.

Failure analysis:

  1. Load short circuit.

  2. Wire phase short circuit.


Troubleshooting:

  1. Discharge the fault and replace it;

  2. Check the short-circuit point of the wire for repair.


Fault 6: AC contactor contact burns.

Failure analysis:

  1. The pressure of the contact spring is too small;

  2. The contact has grease;

  3. The capacity of the contact is not enough.

Troubleshooting:

  1. Adjust the spring pressure;

  2. Remove the dirt;

  3. Replace the larger appliance.


Fault seven: the contacts are welded together

Failure analysis:

  1. The contact is overheated;

  2. The disconnection capacity of the contact is not enough;

  3. The number of times the contact is disconnected is too much.

Troubleshooting:

  1. Eliminate the cause of overheating;

  2. Replace the components with larger capacity;

  3. Replace the contacts.


Fault eight: the coil burned out

Failure analysis:

  1. The spring reaction force is too large to make the coil heat;

  2. The coil voltage does not match the actual circuit voltage.

Troubleshooting:

1. Adjust the spring pressure; 2. Replace the coil.


Fault nine: the armature can not suck

Failure analysis:

  1. The coil is broken or burned out;

  2. The armature or the movable part of the mechanism is stuck.

Troubleshooting:

  1. Repair, replace;

  2. Remove obstacles.


Fault ten: loud noise

Failure analysis:

  1. The power supply voltage is too low;

  2. The contact spring pressure is too large;

  3. The magnetic system is skewed or mechanically stuck, so that the iron core cannot be absorbed;

  4. The core magnetic surface is rusted or greased, dust;

  5. Short circuit ring Breaking; 6. The magnetic core surface wear is excessive and uneven.


Troubleshooting:

  1. Increase the operating loop voltage;

  2. Adjust the contact spring pressure;

  3. Eliminate the mechanical jamming fault;

  4. Clean the core magnetic surface;

  5. Replace the iron core or weld short-circuit ring; 6. Replace the iron core.


Fault 11: The contact is not conducting

Failure analysis:

  1. The contact opening distance is too large, no overtravel

  2. The contact is off;

  3. The contact is not clean;

  4. The moving part is stuck.


Troubleshooting:

  1. Adjust the contact parameters;

  2. Replace the contacts;

  3. Clean the contacts;

  4. Eliminate the stuck fault.


Fault 12: The bell does not ring

Failure analysis:

  1. The fuse FU6 or FU8 is blown;

  2. The fuse is in poor contact;

  3. The bell is in poor contact;

  4. The bell is bad;

  5. The bell button SB7-9 is in poor contact.


Failure analysis:

  1. Check for troubleshooting, replace;

  2. Check if the fuse is in good contact;

  3.  Check if the bell is in good contact;

  4.  Replace;

  5. Repair and replace.


Fault 13: Low speed motor does not run

Failure analysis:

1.Phase loss;

2. Whether the intermediate relay KA2 is closed; 

3. The SB11 button contact is good; 

4. The low speed motor is faulty; 

5. The low speed clutch brake is not released; 6. The low speed clutch coil is burnt out or the contact is poor; Thermal relay FR2 is not turned on or has poor contact.

Troubleshooting:

1.Check the power supply voltage;

2. KA2 pull-in, check KM2; KA2 does not pull in, check whether the KA2 coil is normal; 

3. Check if SB11 is normal; 

4. Check if the low-speed motor is normal; 

5. Check if the low-speed clutch brake is loose ; 

6. Check if the low speed clutch coil is normal; 

7. Check FR2, reset, repair.


Fault 14: Jog does not work.

Failure analysis:

Punctuality: 

1.Whether the punctual button SB13-15 is in good contact;

2. Whether KM2 is normal; 

3. Whether FR2 is normal;

Anti-point: 

1.Is the reverse button switch SB17-19 normal;

2. Is KM3 normal; 

3. Is FR2 normal?

Troubleshooting:

Punctuality: 1. Check SB13-15, repair 2. Same as before 3. Same as before.

Counter point: 

1.Check SB17-19, repair and replace;

2. Check if KM3 works. If it is working, check whether the normally open contact of KM3 is in good contact; if it is not working, check whether the KM3 coil is normal and FR2 is normal.


Fault 15: The operation does not work

Failure analysis:

1.AC contactor KM1 does not pull in;

2. SB21 contact is good or spring is stuck; 

3. SB21 is bad; 

4. FR1 is poorly contacted or tripped.


Troubleshooting:

1.Check if the KM1 coil is normal, such as KM1 pull-in, check whether the normally open contact 3-9 of KM1 is in good contact;

2. repair, replace; 

3. replace;

 4. repair, reset.


Fault 16: Fixed speed does not work

Failure analysis:

  1. The intermediate relay KA3 does not work, it may be the coil burnt out, or it may be poor contact;

2. The button switch SB23 is in poor contact; 

3. SB23 is bad; 

4. SB21 is normal; 

5. KA5 normally closed contact 2-18 Whether the contact is good; 

6. Whether the normally open contact 3-14 of KA3 is connected to the electromagnetic speed controller loop.

Troubleshooting:

  1. Replacement, repair;

2. Maintenance;

3. Replacement; 

4. Check if SB21 is normal; 

5. Check whether the normally closed contact 2-18 of KA5 is normal; 

6. Check whether the normally open contact 3-14 of KA3 is good. .


Fault 17: Can not speed

Failure analysis:

  1. Electromagnetic speed controller fuse burned out

2. Whether the speed controller WT2 is good; 

3. The electromagnetic speed controller is faulty.

Troubleshooting:

1. Replace; 2. Check if WT2 is normal; 3. Check each component of EA2.


Fault 18: No pressure

Failure analysis:

  1. The pressure relay KA9 is bad;

2. The KA9 coil coil is burnt out; 

3. The piezoelectric magnet YA4 is in poor contact or the coil is burnt out; 

4. The empty head is over the head to control the contact of the electric tooth with the ground; 

5. The metal detector is off the magnetic switch SQ9;

 6.KA6 coil bad contact or burnout; 

7. The components of the combined pressure circuit are faulty.

Troubleshooting:

  1. Maintenance;

2. Replacement;

3. Repair or replacement; 

4. Maintenance, inspection of electric teeth; 

5. Maintenance; 

6. Maintenance, replacement; 

7. Inspection of the components of the pressure circuit.


Fault 19: no pressure

Failure analysis:

  1. The paper feed button SB03 is not reset;

2. The electromagnetic switch SQ8 is out of control; 

3. The empty sheet is over-headed to control the electric teeth without electric shock; 

4. The KA5 armature is stuck or unable to be sucked.

Troubleshooting:

  1. Repair to reset the SB03;

2. Repair or replace; 

3. Repair to touch the ground; 

4. Repair or replace.


Fault 20: paper feeding does not work

Failure analysis:

  1. The paper feed clutch YA02 is in poor contact or burnt out;

2. The paper feed relay KA01 is in poor contact or the coil is burnt out; 

3. The empty open head controls the electric tooth to touch the ground to make KA5 pull in; 

4.SQ06, SB04, SB05, SB06 Whether the contact is good; 

5. The double control relay KA04 has been sucked.

Troubleshooting:

  1. Repair or replace;

2. Repair or replace; 

3. Check empty head over the control contact (electric teeth) should not be grounded; 

4. Check whether SQ06, SB04, SB05, SB06 is normal; 

5. Eliminate double control failure.


Fault 21: Paper feed automatically rises and does not work

Failure analysis:

  1. The limit switch SQ07 is in poor contact or broken;

2. The intermediate relay KA02 is in poor contact or the coil is burnt out; 

3. The paper feed clutch YA02 is in poor contact or burnt out; 

4. The paper feed automatic ascending loop is faulty.

Troubleshooting:

  1. Repair or replacement;

2. Repair or replacement; 

3. Repair or replacement; 

4. Check the components of the automatic rise loop of the paper feed.


Fault22: the main delivery table automatically drops not working

Failure analysis:

  1. The limit switch SQ12, SQ17 is in poor contact or broken;

2. The micro switch SQ13 is in poor contact or broken; 

3. The AC contactor KM5 has poor contact or burnout; 

4. Phase loss; 

5. Overload.

Troubleshooting:

1. Repair or replace; 2. Repair or replace; 3. Check if KM5 is good; 4. Check fuse FU4; 5. Check the cause of overload and reset FR4.


Fault 23: the vice-carrying cardboard does not move.

Failure analysis:

  1. Transistor time relay KT1 bad contact or coil burnout;

2. Magnetic switch SQ15 bad contact or broken; 

3. Metal detector displacement; 

4. Limit switch SQ12 bad contact or broken; 

5. AC contactor KM8 Poor contact or burned out of the coil; 6. overload; 7. lack of phase.

Troubleshooting:

  1. repair or replacement;

2. repair or replacement; 

3. reset; 

4. repair or replacement; 

5. repair or replacement; 

6. check the cause of overload, reset FR7; 

7. change the fuse to fuse.


Fault24: clutch speed can not be adjusted, only high speed can not run at low speed (out of control)

Failure analysis:

1. Slip no-load operation; 2. No feedback

Troubleshooting:

1. Add a certain load; 2. Increase the feedback amount, rotate the WT4 counterclockwise, and adjust to a certain required speed.


Fault 25: turn on the power switch fuse blown

Failure analysis:

  1. Load short circuit;

2. Lead wire short circuit; 

3. Transformer primary short circuit; 

4. SCR breakdown.

Troubleshooting:

  1. Check if the clutch coil is normal;

2. Check if the output voltage wire is short-circuited; 

3. Check if the transformer is normal; 

4. Check if the thyristor is normal, or replace it.


Fault 26: Turn on the power switch indicator light, the rotary speed controller clutch does not work

Failure analysis:

  1. T1, T2 open circuit;

2. Speed control knob open circuit; 

3.G2 damage; 

4.G1 damage; 

5.SCR open circuit; 

6.Printed circuit socket contact bad; 

7.Transformer B3,4,5,6,11, 12, 13, 14 with or without voltage.

Troubleshooting:

  1. Check whether T1 and T2 are in good contact with or without DC voltage;

2. Check WT1, adjust WT2, and measure the terminal voltage of R5 at 4-6V; 

3. Check and replace G2; 

4. Check and replace G1; 

5.Check the SCR; 

6. Check if the printed circuit board socket is normal; 

7. Check if the secondary voltage of the transformer is normal.


Fault 27: Excitation voltage output when WT2 has been adjusted to zero

Failure analysis:

  1. The ambient temperature is too high;

2. The initial zero adjustment is improper;

Troubleshooting:

  1. Reduce the indoor temperature to below 45 degrees;

2. Adjust WT5 so that the SCR has no output when the WT2 is at zero position.


Fault 28: The speedometer does not match the actual speed, or cannot be adjusted (low)

Failure analysis:

  1. The speed measuring generator demagnetizes;

2. The speed measuring generator has a phase short circuit or broken line.

Troubleshooting:

  1. Adjust WT3;

2. Check if the three-phase voltage of the tachogenerator is symmetrical.


Fault 29: the clutch can only run at low speed and cannot increase speed

Failure analysis:

  1. The feedback amount is too large;

2. Diode D26 breaks down or opens.

Troubleshooting:

  1. Adjust WT2 to reduce the feedback amount, adjust WT2, increase the given amount;

2. Replace D2.


Above we have some analysis of the common faults of the printed circuit of J2108A.

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