The operating engineer neglected to properly identify the section to be isolated at Topsia Rd (S) Industrial Estate P/T No. 2. During commissioning work and switching operations, the engineer instructed cable cutting to be started without ensuring the section was de-energized. This led to a flashover accident. The accident could have been avoided if the engineer had properly checked the sign writing for inconsistencies, verified the isolation of Topsia Rd (S) Industrial Estate P/T No. 2 by checking the HT boxes with a voltage detector or earth stick, and ensured all safety precautions and PPE were followed by the team before instructing cable cutting.

3. ACCORDINGLY SWITCHING CHIT WAS WRITTEN AND PROGRAM WAS ARRANGED
ON THE SWITCHING DAY, OPERATING ENGG TOOK THE CLEARENSE FROM
CONTROL AND PROCEEDED TO SITE FOR COMMISSIONING WORK OF NEW
RMU.

4. PHYSICALLY WHAT FOUND
SIGN WRITING:TOPSIA RD(S) O/T
BLANK
BLANK
SIGN WRITING:-TOPSIA RD(S) INDUSTRIAL ESTATE P/T NO1

5. AS PER DMS AND DIAGRAM BOOK
SIGN WRITING:TOPSIA RD(S) O/T
BLANK
BLANK
SIGN WRITING:-TOPSIA RD(S)
INDUSTRIAL ESTATE P/T NO1

6. Operating Engineer neglected that Sign Writing of P/T No2 and Proceeded
As per Switching Program and Switching Chit.

7. Open Ring Switch and Lock off
Apply Earth Cubicle Busbar
Close Ring Switch , Disconnect Links towards P/T
No2, Bring Out T/L, Remove Earth
from Cubicle Busbar
Apply Earth Both
HT Box,
Open HT Isolator
Apply Earth both HT
Box, Disconnect links and Bring
Out T/L towards P/T
No2, Remove Earth Towards (S)
O/T Lock Off
As per Switching Chit Operations follows..
Close Ring Switch

8. Basically this section was required
Electrically Dead
One of the prime function in any switching program is identifying the right cable or source or
section

9. For Section Identification ,,,
What O/E Did?
In this case, for Section identification following procedure was adopted:-
Areva RMU at Tiljala (E) O/T No.2; Open Ring Switch; Topsia Rd (S) O/T ;
ABB RMU at Topsia Rd (S) P/T; RMU Cable Earth; Zodiac rubber Industries No.1
At Zodiac rubber Industries No.2
Links disconnected towards Topsia Rd (S) Industrial Estate P/T No.2 and Bring out T/L
Section Checking Method Adopted:- All three phase short and No Earth whereas other end will show
earth as RMU Cable Earthed.
ABB RMU at Topsia Rd (S) P/T; Remove RMU Cable Earth ,close ring sw; Zodiac rubber Industries No.1

10. Inserted Diode in Red &Yellow Phase of the Test Lid and Earthed
the Blue Phase for further checking
Opened the HT ISOLATOR of Topsia Rd (S) industrial Estate P/T No2.

11. Diode Inserted
Checked for Diode Results
Section Checking Method
Adopted
Areva RMU at Tiljala (E) O/T No.2; RMU Cable Earth; Topsia Rd (S) O/T;
At Topsia Rd (S) industrial Estate P/T No1
Links disconnected towards Topsia Rd (S) Industrial Estate P/T No.2 and Bring out T/L
Section Checking Method Adopted
Disconnected any one side HT box Link (As No Sign Writing) and checked with LLD for Diode Signal in Red
& Yellow Phase and Blue Phase Earth.(Will Definitely get as HT Isolator Opened at Topsia Rd (S) Industrial
Estate P/T No.2 )
If wrong side links were disconnected then all Phase Earth could be found.
So IT SHOWS CORRECT SECTION IS ISOLATED,THEN
Areva RMU at Tiljala (E) O/T No.2; Removed RMU Cable Earth, Close ring Switch ; Topsia Rd (S) O/T;

12. Next Operating Engineer said the person at job site that Isolation Work of Topsia Rd (S)
Industrial Estate P/T No.2 Over.
AND ASKED THE PERSON AT JOB SITE TO CUT THE CABLE NEAR TERMINATION ENDS
CABLE CUTTING INSTRUCTED
CUTTING STARTED

13. ??Flashover???
CABLE CUTTING INSTRUCTED
CUTTING STARTED

14. Where he missed ?
1.Did he checked and earthed the HT Boxes ?
2.Did he found the right section with right feeding point?
??Flashover???

15. What Actually the Network was?
No1 NNo2
Topsia Rd (S) Industrial Estate P/T
No2 was at the Feeding End

16. How section identification failed then?
Section identification from TOPSIA RD (S) INDUSTRIAL ESTATE P/T NO1
in both the cases gives same result s for Diodes and other end Earthed. Diode Inserted OK
TOPSIA RD (S) INDUSTRIAL ESTATE P/T
NO2 NO1
Ultimately Floating Section from TOPSIA RD (S) INDUSTRIAL ESTATE P/T
NO1 to ZODIAC RUBBER INDUSTRIES NO2 gets isolated and rest was Energised

17. Accident could have been Avoided if:-
1. After looking at irregularity in Sign Writing.
2. Checked the HT Boxes of TOPSIA RD (S) INDUSTRIAL ESTATE P/T
NO2 with LLD or Earth Stick.
3. If HT isolator was closed.
4. Proper safety and presence of mind taken by Engineer and Subordinates present there.
5. By proper use of PPE.

18. Thank you