--%>
Assignment Help - homework help

  Troubleshooting Chart of DC Machines

Troubleshooting Chart - D.C. Machines:

A) Symptom:  Failure to build up of voltage (dc generator)

Possible Cause of Trouble:

  • Faulty Voltmeter, test output voltage with separate voltmeter. Open field resistor.
  • Open field circuit. Test coils for open circuit or loose connections.
  • Nonexistence of residual magnetism in self excited generator.
  • Dirty commutator, high mica, brushes not comprising good contact with commutator.
  • New brushes seated but not contacting enough area.
  • Armature shorted internally to ground.

Remedy:

  • Change voltmeter. Replace or repair resistor
  • Change defective coils, tighten or solder loose connections.
  • Flash the field. Connect battery to field with correct polarity permit current momentarily and cut off. Field will resume residual magnetism.
  • Within cut mica, clean or dress commutator.
  • Change or reseat brushes, free if binding in holders.
  • Brush bedding and reseat brushes. Eliminate, test and repair or replace.

B) Symptom: Output voltage too low (dc generator)

Possible Cause of Trouble:

  • Grounded or shorted field coil. Shorted filtering capacitor; open filter choke, open ammeter shunt, broken brush shunts.
  • Prime mover speed low (test speed)
  • Brushes not seated properly. Commutator dirty, or film very heavy

Remedy:

  • Test, repair or replace. Adjust governor on prime Mover. Reseat brushes.
  • Clean commutator with fine sand paper. Change brushes with appropriate grade set or Use complete new set of brushes
  • Adjust correctly. Connect properly

C) Symptom: Output voltage too high (dc generator)

Possible causes of trouble:

  • Field resistor not appropriately adjusted
  • Reversed  field  coil  or armature coil connections
  • Prime mover speed too high.
  • Faulty voltage regulator
  • Overloaded.

Remedy:

  • Adjust governing device.
  • Adjust or change faulty voltage regulator.
  • Test speed.

D) Symptom: Armature too hot

Possible causes of trouble:

  • Test meter readings against name plate rating.
  • Excessive brush pressure.
  • Belt very tight or coupling not aligned.
  • End plate out of position. Bent shaft.
  • Armature coil shorted Armature striking poles. Test bearing for play and air gap for correct spacing, shaft for bent condition.
  • Poor ventilation. Clogged air passages.
  • Repeated changes in load In bulk. Examine meter readings.

Remedy:

  • Decrease load.
  • Adjust pressure or replace tension springs.
  • Adjust belt. Align units properly.
  • Assemble accurately.
  • Straighten on lathe or replace.
  • Repair or replace armature. Replace bearings.
  • Straighten shaft or replace Armature.
  • Clean clogged air passages. Give clearance. For circulation of air around equipment. Clean equipment.
  • Faulty design. Generator should be employed in steady load application.

Latest technology based Electrical Engineering Online Tutoring Assistance

Tutors, at the www.tutorsglobe.com, take pledge to provide full satisfaction and assurance in Troubleshooting Chart of DC Machines homework help via online tutoring. Students are getting 100% satisfaction by online tutors across the globe. Here you can get homework help for Troubleshooting Chart of DC Machines, project ideas and tutorials. We provide email based Troubleshooting Chart of DC Machines homework help. You can join us to ask queries 24x7 with live, experienced and qualified online tutors specialized in Troubleshooting Chart of DC Machines. Through Online Tutoring, you would be able to complete your homework or assignments at your home. Tutors at the TutorsGlobe are committed to provide the best quality online tutoring assistance for Electrical Engineering homework help and assignment help services. They use their experience, as they have solved thousands of the Electrical Engineering assignments, which may help you to solve your complex issues of Troubleshooting Chart of DC Machines. TutorsGlobe assure for the best quality compliance to your homework. Compromise with quality is not in our dictionary. If we feel that we are not able to provide the homework help as per the deadline or given instruction by the student, we refund the money of the student without any delay.