2014 Electrical Engineering Safety Seminar 5 & 6 November at Sydney's Waterview Park

1. OPTIONS FOR MANAGING SAFETY WITH ELDERLY SWITCHGEAR

Richard Blakeley, R.P.S. Switchgear,

2. SWITCHGEAR – WHAT DOES IT DO?

MAKE AND BREAK NORMAL LOAD CURRENTS

OPERATE CONTINUOUSLY UP TO NORMAL RATINGS

WITHSTAND THE PASSAGE OF THROUGH-FAULT CURRENT FOR SUFFICIENT TIME TO ALLOW THE DOWNSTREAM PROTECTION TO OPERATE

SAFELY SWITCH ON TO FAULT, HANDLING THE ENERGIES INVOLVED

SAFELY INTERRUPT FAULT CURRENT AND THEREBY REMOVING THE FAULTED EQUIPMENT FROM THE SOURCE OF ELECTRICAL SUPPLY

ACT AS A POINT OF ISOLATION AND EARTHING TO ENABLE WORK TO BE DONE SAFELY

3. Reyrolle, Type ‘AR’ 33kv, 800A Switchgear,

PRIMARY CONTACTS -- FIXED AND MOVING.

ARCING CONTACTS -- FIXED AND MOVING.

CLOSING MECHANISM -- (Stored Energy, MO or Manual),

OPENING MECHANISM -- STORED ENERGY

PRIMARY INSULATION SYSTEM,

ENCLOSURE,

MEANS OF ISOLATION FROM THE SYSTEM.
CIRCUIT BREAKER DESIGN -- TRADITIONAL COMPONENTS

4. Risk Factors with Elderly Switchgear

5. AGING SWITCHGEAR – RISKS & ISSUES

Lack of knowledge/training

Network changes resulting in the switchgear being overstressed

Not being modified as per manufacturer’s advice/updates

Not being maintained or operated properly

Dependent-manual switchgear

Spares & Technical Support not being available

Age related failure,

Switchgear is normally ‘quiescent’

Continuous assessment not justifiable

True condition difficult to determine

6. ELDERLY SWITCHGEAR – TRUE CONDITION??
“In on-site evaluation tests carried out by Reyrolle on aging oil switchgear worldwide, it was found that on more than 50% of oil switchgear thought to be in good condition, the circuit breakers had faults or were operating outside of their design envelope and in some cases would have failed to operate correctly under system fault conditions”

7. SWITCHGEAR FAULT CLEARANCE – KEY FUNCTION FOR SAFETY

8. ISSUES WITH ELDERLY SWITCHGEAR

ELDERLY OIL SWITCHGEAR PRESENTS INCREASING RISK , (Consequences of a flashover can be severe)

CONDITION ASSESSMENT OF DISTRIBUTION SWITCHGEAR IS DIFFICULT

SPARES ARE NOT AVAILABLE FOR MOST ELDERLY SWITCHGEAR,

NOT UPGRADED TO LATEST REVISION,

NOT COMPLIANT WITH MODERN SAFETY STANDARDS,

SWITCHING PERFORMANCE OF OIL CB’s NOT GOOD AT LOWER FAULT LEVELS,

9. Internal Arc/Arc Flash Faults

10. ARC FLASH FAULTS
HOW OFTEN DO THEY HAPPEN?
“EVERY DAY, 1 TO 2 ARC FLASH RELATED FATALITIES OCCUR ACROSS NORTH AMERICA”

11. INTERNAL ARC FAULTS – CAUSES

Badly Designed Switchgear

Incorrect Installation

Insulation Failure
▫
Contamination
▫
Age Deterioration
▫
Overstressing
▫
Human Intervention
▫
Vermin Ingress

Lack of/Inadequate Maintenance

Human Error or Misuse

Over-stressing

12. ENERGY RELEASED BY ARC FAULT
PRESSURE RISE
VISUAL & ACCOUSTIC PHENOMENA
TEMPERATURE RISE
EFFECTS OF FAULT ARC
CONSEQUENCES FOR PLANT
MECHANICAL STRESSING OF ENCLOSURES
THERMAL STRESSING, MELTING, VAPOURISATION
CONSEQUENCES FOR PERSONNEL
SHOCK WAVE, FLYING DEBRIS, OPENING PANELS
EJECTION OF FLAMES & HOT GASES, METAL VAPOUR
EFFECTS AND CONSEQUENCES OF AN ARC FAULT IN HIGH VOLTAGE SWITCHGEAR

13. THE CONSEQUENCES OF AN INTERNAL ARC FAULT IN HV SWITCHGEAR

14. THE CONSEQUENCES OF AN INTERNAL ARC FAULT IN HV OIL SWITCHGEAR

15. ARC-FAULT IN NON-VENTED SWITCHGEAR
SOME INTERESTING DATA FROM RPS TESTING OF ELDERLY SWITCHGEAR

Current starts: 0

Pressure starts: 0.4 ms

Pressure peak: 4.7 ms

Pressure duration: 6.6 ms

Current peak: <10 ms
Data & Test evidence supports that the covers will be flying off in 5 – 10 ms
Maximum pressure on switchgear panels/doors can be 1-2 bar

16. Safety Solutions & Improvements for Existing Switchboards

17. 
TO IMPROVE SAFETY FOR OPERATORS AND STAFF,

TO REDUCE MAINTENANCE AND LIFETIME OWNERSHIP COSTS,

TO IMPROVE THE RELIABILITY AND THE SERVICE-ABILITY OF THE CIRCUIT BREAKERS.

TO INCREASE THE RATING OF THE SWITCHBOARD, (X/R, Normal & Short cct)

TO FURTHER EXTEND THE REMAINING LIFE OF THE ASSET BY REPLACING KEY COMPONENTS AS REQUIRED, (BUSHINGS, CT’S, VT’S ETC)

TO MODERNISE THE CONTROL & PROTECTION EQUIPMENT.

TO ACHIEVE THE ABOVE WITH MINIMUM SYSTEM DISRUPTION.
KEY STRATEGIC OBJECTIVES FOR LIFETIME SUPPORT OF AGING SWITCHGEAR ASSETS.

18. SUMMARY OF SWITCHGEAR SOLUTIONS,

SAFETY RETROFITS,

CIRCUIT BREAKER RETROFIT,

ARC DOOR + END SHIELD RETROFIT,

3-SIDED ‘CONTAINMENT’

‘REMOTE OPERATION’

UPGRADES & LIFE EXTENSION,

CURRENT TRANSFORMER REPLACEMENT,

CABLE BOX RETROFIT,

REPLACEMENT OF ORIFICE BUSHINGS,

REPLACEMENT OF VT’s

PROTECTION & CONTROL UPGRADE,

19. Circuit Breaker Retrofit

20. CIRCUIT BREAKER RETROFIT
Existing LMT panel
Oil Circuit Breaker out
Vacuum Circuit Breaker in
(Brand new unit)
OCB TO VCB REPLACEMENT

ABOUT A DAY PER CIRCUIT

MINIMAL DISRUPTION

SIGNIFICANT SAFETY IMPROVEMENT
>6,000 units in service world-wide

21. RETROFIT CIRCUIT BREAKER FOR REYROLLE ‘LM’ SWITCHGEAR

SIMPLE MODULAR DESIGN

PROVEN CAST EPOXY RESIN INSULATION SYSTEM

CAPABLE OF MORE THAN 10,000 LOAD CURRENT OPERATIONS

PROVEN LONG LIFE, LOW MAINTENANCE MECHANISM

LESS THAN 30% OF THE PARTS OF LMT

CAPABLE OF OVER 50 SHORT-CIRCUIT OPERATIONS AT 25KA AT 12KV

EXCELLENT SWITCHING PERFORMANCE, (25ms opening, >45% dc component)

22. 
DIRECT REPLACEMENT FOR LM RANGE,

SIGNIFICANTLY IMPROVES SAFETY IN THE SUBSTATION,

LESS THAN 1 DAY PER CIRCUIT, (Fast Implementation, minimum disruption)

SHORT CIRCUIT WITHSTAND RATING OF THE SWITCHBOARD CAN BE INCREASED UP TO 31.5kA ,

REMOVES OIL HANDLING,

REPLACES CB WITH LONG LIFE, LOW MAINTENANCE UNIT,

LOW COST W.R.T. COMPLETE SWITCHBOARD REPLACEMENT, (<30%)

ALLOWS SUBSTATION ASSETS TO BE RENEWED & REVALUED COST EFFECTIVELY,
RPS LMT SWITCHGEAR RETROFIT -- SUMMARY

23. FURTHER SAFETY FOR EXISTING SUBSTATIONS
“REPLACEMENT OF THE O.C.B. WITH OUR VACUUM UNIT IS A SIGNIFICANT IMPROVEMENT IN OPERATOR SAFETY”
BUT THERE ARE OTHER IMPORTANT SAFETY FEATURES THAT ARE AVAILABLE TO SIGNIFICANTLY IMPROVE SAFETY AND BRING THE EXISTING SWITCHBOARD TOWARDS 62271-200 FOR INTERNAL ARC SAFETY”

24. FURTHER SAFETY FOR EXISTING SUBSTATIONS
SWITCHGEAR SAFETY UPGRADES:

Arc-proof doors + end shields

3 sided containment

Electrical operation ‘not-in-front’

25. EXISTING SWITCHGEAR & INTERNAL ARC SAFETY

EXISTING SWITCHBOARDS HAVE NO INTERNAL ARC WITHSTAND OR PRESSURE RELIEF DESIGN,

HUMAN PRESENCE IN FRONT OF THE LIVE SWITCHBOARD IS UNAVOIDABLE

SAFETY FOR OPERATORS, STAFF AND VISITORS IN FRONT OF THE EXISTING SWITCHBOARD IS ACHIEVABLE,

RACKING THROUGH A CLOSED ARC-PROOF DOOR IS ESSENTIAL.
TYPICAL EXISTING LMT SWITCHBOARDS

26. 
WHY HAVE AN ARC-PROOF DOOR?

WHY HAVE RACKING THROUGH AN ARC-PROOF DOOR?
TWO IMPORTANT QUESTIONS:-
EXISTING SWITCHGEAR & INTERNAL ARC SAFETY

27. WHY HAVE AN ARC-PROOF DOOR?
LMT TEST ARRANGEMENT

STANDARD LMT PANEL

FAULT IN BREAKER COMPARTMENT

25KA, 1S DURATION

OCB WOULD BE MUCH WORSE

28. WHY HAVE AN ARC-PROOF DOOR?
...from a different angle

29. WHY HAVE RACKING THROUGH AN ARC-PROOF DOOR?

30. BEHIND CLOSED DOOR RACKING
RETROFIT ARC-PROOF DOOR – OPERATOR SAFETY
Behind Closed Door Racking

31. RETROFIT END SHIELDS – OPERATOR SAFETY

PREVENTS BURN-THROUGH,

PROVIDES LATERAL SAFETY

SIMPLE INSTALLATION

NO BUS OUTAGE REQUIRED

END PANEL CCT OUTAGE ONLY

32. RETROFIT OF , 25kA, 1s ARC WITHSTAND FRONT DOOR & END SHIELDS FOR OPERATOR SAFETY`

LMT SWITCHBOARDS RETROFITTED WITH ARC DOORS & END SHIELDS.
END SHIELD.

33. RETROFIT OF ARC-WITHSTAND FRONT DOOR
Brunei
Australia
South Africa
United Kingdom

34. ARC DOORS REDUCE THE HRC – NFPA 70E
Activity
Existing switchgear
With arc-doors & end shields
Circuit breaker operation
4
0/1
Circuit breaker racking
4
0/1
Instrument cubicle work/inspection
4
0/1
Maintenance work in front of switchboard
4
0/1
Relay inspection/testing
4
0/1
General presence in the switch-room in front of the switchboard
4
0/1

35. 3-SIDED CONTAINMENT SYSTEM

36. 3-SIDED CONTAINMENT SYSTEM

37. TEST ARRANGEMENT

LMT PANELS FITTED WITH ARC WITHSTAND KIT

FAULT IN BREAKER COMPARTMENT

25KA, 1S DURATION

CERTIFIED TO IEC 62271-200

3-SIDED SAFETY, 2.8M ROOF
ARC DOOR TEST TO LATEST STANDARD

38. ‘REMOTE’ OPERATION
Option 1 – Remote Control Panel
•
Dedicated control for each panel
•
One set of trip & close operators with key to determine panel
Option 2 – Remote Control Pendant
•
Lead length: 10m, 15m or request
•
Plugs into panel to be operated

39. Other Retrofit & Upgrade Solutions

40. RETROFIT OF CT CHAMBER & CABLE BOX
PITCH-FILLED CABLE BOX REPLACED WITH AIR CABLE BOX.
ENCAPSULATED CAST RESIN CT’s REPLACED WITH SLIP-OVER TYPE

41. RETROFIT OF CT CHAMBER

SLIP-OVER CT RETROFIT KIT FOR LMT

ASSEMBLED, JIGGED AND POURED IN THE FACTORY

COMPLETE INSTALLATION

42. 
REPLACES THE CABLE BOX & CABLE BOX BUSHINGS ONLY, -- OR

ALSO REPLACES THE EXISTING CAST RESIN CT’S WITH SLIP-OVER TYPE,

INCLUDES NEW CT ORIFICE BUSHINGS AND CT BUSHINGS,

IMPROVED FUTURE PROTECTION FLEXIBILITY,

LIVE LINE INDICATION & PHASING AVAILABLE,

CONVERTS EXISTING CAST PITCH-FILLED BOX TO AIR TERMINATION,

EASY TO IMPLEMENT, -- PER CCT OUTAGE ONLY,
CABLE BOX REPLACEMENT
400A/800A FEEDER PANEL CONVERTED TO AIR BOX.
400A/800A FEEDER PANEL BEING CONVERTED TO AIR BOX.

43. VT REPLACEMENT – MOVING PORTION

RPS manufacture & supply a direct replacement truck for the existing Reyrolle LMT VT’s

Fast replacement – no bus-bar outage required

Isolating and Engaging the VT through the Instrument cubicle is available for the new VT arrangement
Replacement VT trucks for LMT

44. PROTECTION & CONTROL UPGRADE

Replaces the existing RMI “top-box”

Complete new RMI modernisation

Equipped, wired & tested in the factory

Customised to specific customer requirements

Simplifies site work

45. LMT SWITCHBOARD FITTED WITH SAFETY, PROTECTION & CONTROL IMPROVEMENTS

46. LMT SWITCHBOARD FITTED WITH RPS IMPROVEMENTS

RETROFIT VCB’S,

RETROFIT ARC DOORS

PROTECTION & CONTROL UPGRADE,

RETROFIT RMI CUBICLES,

CT & VT UPGRADES,

SWITCHBOARD FAULT RATING INCREASED FROM 13.1kA UP TO 31.5kA.
“Upgraded to modern standards for 40% of the cost of switchboard replacement”

47. SUMMARY – ELDERLY SWITCHGEAR RETROFIT OPTIONS
SAFETY UPGRADES:

OCB to VCB upgrade

Arc-proof doors + end shields

3 sided containment

Electrical operation ‘not-in-front’
ADDITIONAL RETROFITS:

RMI cubicles

Busbars

VT’s – bus and circuit

CT’s

Cable boxes
Existing aged switchgear can be made safer & upgraded