CHRONOLOGY OF EVENTS:

- March 21, 0530 HRS: G-202 Output voltage dropped to zero. Unit was shut-down manually by the Operator because the Under-Voltage

Security is not available on the unit. Stand-by Gas Generator could not be commissioned due to unavailability of Fuel Gas at Paniro

Facility after Paniro-7 JP relocation

- March 21, 0700 HRS: Maintenance Team arrived and removed the end-cover of G-202 to determine the problem and subsequently

assess the extent of damage. Exciter armature and coil windings were found damaged due to friction. NDE Bearing of the unit was found

broken with its metallic shield broken off.

- March 21, 0930 HRS: G-4505 relocated from Rind Remote was tested at the Work-Shop. It’s AVR was found to be faulty and was

replaced.

- March 21, 1030 HRS: G-4505 was loaded onto truck for shifting to Paniro after successful testing.

- March 21, 1500 HRS: G-4505 was successfully commissioned and Paniro Facility was brought back online.

5-WHY ANALYSIS

Paniro Generator G-202: 5 Why Analysis

Problem Statement

G-202 output dropped to zero. Burning smell observed and unit was manually shut down by the Operator

Why Exciter armature winding was damaged. This caused the output to drop down

Why Exciter Armature chafed against the Excitation Coil, damaging both the winding and the laminar plates

Why Exciter Rotor's NDE bearing (Type 6313ZZ) failed

Why Run-to-failure philosophy for sealed bearings

Why -

G-202 Failure at Paniro Facility

G-202 Failure at Paniro Facility

Figure 1 Exciter Stator Lamina - Friction Damage

Figure 2 Exciter Rotor - Winding Burnt Out, Lamina Damaged due to Friction

Figure 3 Damaged NDE Bearing