Voltage Drop on Load

1. RRA diodes faulty.

Check the diode with multimeter replace it if faulty.

2. Voltage droop adjusted to maximum.Set the droop pot as per the requirement. If the set is running in single operation remove or short QDCT from alternator.

3. Large speed drop on engine or engine speed goes to low with the load. Check that engine speed droop from no load to full load is no greater than 4%.

4. Unbalance load.Check voltages on all phases and current. If unbalanced request customer to redistribute the load more evenly across the phases.

5. Excitation windings (Main field wdg., Excitor Stator wdg., Excitor rotor wdg.) Faulty. Check IR value and resistance of excitation windings. If faulty call the machine at works for repairs.

6. Load surges exceed 2.4 times the full load current.Check load surges with clip-on ammeter . Voltage dip may exceed if it overload exceeds 2.4 times the full load current. Request customer to not to start such type of load.

7. AVR faulty

Replace the AVR.