OSHA Accident Investigation · Summary #14543243

BURN,CLOTHING,OIL CIRCUIT BREAKER,MAINTENANCE,ELECTRICAL,E PTD,ELEC UTILITY WORK,ELECTRICAL FAULT

1984-08-02T00:00:00

Event: BURN,CLOTHING,OIL CIRCUIT BREAKER,MAINTENANCE,ELECTRICAL,E PTD,ELEC UTILITY WORK,ELECTRICAL FAULT
Linked inspection: No inspection record linked to this accident's victims.
Summary number: 14543243
Report ID: 317740

Event description

BURN - ELECTRICAL - FAULT IN OIL CIRCUIT BREAKER

Investigation abstract

SEVEN POWER GROUP DEPARTMENT EMPLOYEES WERE ASSIGNED TO PERFORM MAINTENANCE ON A MMETER. THE CHECK SHOWED NO LOAD. HE THEN ATTEMPTED TO OPEN THE 6.9-KILOVOLT OIL CIRCUIT BREAKER. AS HE OPENED THE BREAKER, A LARGE FLASH OCCURRED, AND THE BUIL DING CAUGHT ON FIRE. (THE OIL CIRCUIT BREAKER WAS A GENERAL ELECTRIC FK BREAKER #S DKL 140569 59406, WSF 23308; RATED 300 AMPERES, 15 KILOVOLT, 3-PHASE; A SINGL E-TANK UNIT OF 1920 VINTAGE.) EMPLOYEES # 1, 2, AND 3 WERE INSIDE THE OIL CIRCUI T BREAKER BUILDING, AND EMPLOYEES #4, 5, 6, AND 7 WERE OUTSIDE THE BUILDING WHEN THE FLASH OCCURRED. SIX EMPLOYEES SUFFERED BURNS. ONE HAD LACERATIONS AND CONTU SIONS. THE BUILDING HOUSING THE BREAKER WAS KNOWN TO HAVE A LEAKING ROOF. THIS C OULD HAVE ALLOWED WATER TO CONTAMINATE THE OIL IN THE TANK, RESULTING IN A DIMIN ISHED ARC-QUENCHING CAPABILITY OR RESULTING IN A FAULT TO GROUND. ADDITIONALLY, 6.9-KILOVOLT, 25-CYCLE TRANSFORMER BANK. THE MAINTENANCE WAS TO INCLUDE INSPECT THE OIL CIRCUIT BREAKER HAD NOT RECEIVED SCHEDULED SERVICE OR REPAIR SINCE 1971 (13 YEARS EARLIER). ING THE EQUIPMENT, CHANGING THE CIRCUIT BREAKER OIL, AND CLEANING THE TRANSFORME R BUSHINGS. THE WORK WAS TO BE COORDINATED SO THAT THE BUILDING HOUSING THE OIL CIRCUIT BREAKER COULD BE REPAIRED BY CARPENTERS AT THE SAME TIME. BEFORE THE MAI NTENANCE WAS STARTED, IT WAS NECESSARY TO ISOLATE THE EQUIPMENT FROM THE POWER S OURCE. EMPLOYEE #1 CLOSED THE 230-VOLT TIE DISCONNECTS AND OPENED 6 DELTA DISCON NECTS TO TAKE THE LOAD OFF THE SECONDARY POWER SIDE. HE PLACED RED TAGS ON EACH DELTA DISCONNECT. EMPLOYEE #1 THEN CHECKED CURRENT TO THE TRANSFORMERS WITH AN A

Victims (7)

#1 Fatality Age 54 M

Nature of injury
5

Part of body
19

Event type
14

Source
15

Occupation code
999

Human factor
1

Environmental factor
18

Task assigned
1
#2 Hospitalized Age 37 M

Nature of injury
5

Part of body
19

Event type
14

Source
15

Occupation code
999

Human factor
1

Environmental factor
18

Task assigned
1
#3 Hospitalized Age 56 M

Nature of injury
5

Part of body
19

Event type
14

Source
15

Occupation code
999

Human factor
1

Environmental factor
18

Task assigned
1
#4 Hospitalized Age 50 M

Nature of injury
5

Part of body
19

Event type
14

Source
15

Occupation code
999

Human factor
1

Environmental factor
18

Task assigned
1
#5 Hospitalized Age 59 M

Nature of injury
5

Part of body
19

Event type
14

Source
15

Occupation code
999

Human factor
1

Environmental factor
18

Task assigned
1
#6 Hospitalized Age 35 M

Nature of injury
5

Part of body
19

Event type
14

Source
15

Occupation code
999

Human factor
1

Environmental factor
18

Task assigned
1
#7 Hospitalized Age 37 M

Nature of injury
3

Part of body
13

Event type
14

Source
15

Occupation code
999

Human factor
1

Environmental factor
18

Task assigned
1

Codes shown verbatim from OSHA's accident-investigation database. A human-readable decoder is coming in a future release once the accident_lookup2 dictionary is loaded.