Condition Monitoring of Oil Condition Monitoring of Oil Filled Ring - - PowerPoint PPT Presentation

Condition Monitoring of Oil Condition Monitoring of Oil Filled Ring Main Units Filled Ring Main Units

FACTS FACTS FACTS FACTS

• Oil Filled Ring Main Units are a critical part

Oil Filled Ring Main Units are a critical part

• Oil Filled Ring Main Units are a critical part

Oil Filled Ring Main Units are a critical part

• f networks
• f networks
• Maintenance is infrequent (every 5

Maintenance is infrequent (every 5 10 10

• Maintenance is infrequent (every 5

Maintenance is infrequent (every 5-10 10 years) years) D t il f ti d ti it i D t il f ti d ti it i

• Details of operations and wear activity is

Details of operations and wear activity is unknown unknown

BACKGROUND (UK) BACKGROUND (UK) BACKGROUND (UK) BACKGROUND (UK)

• 1998: EA Technology in co

1998: EA Technology in co-operation with

• peration with
• 1998: EA Technology, in co

1998: EA Technology, in co operation with

• peration with

several Utilities, undertook extensive several Utilities, undertook extensive investigation to: investigation to: investigation to: investigation to:

 Determine how long oil can be left in equipment

Determine how long oil can be left in equipment Detect unacceptable electrical /mechanical wear Detect unacceptable electrical /mechanical wear

 Detect unacceptable electrical /mechanical wear

Detect unacceptable electrical /mechanical wear

• Oil samples were analysed and physical

Oil samples were analysed and physical i ti f h d d f 30 i ti f h d d f 30 40 ld 40 ld examination of hundreds of 30 examination of hundreds of 30-40 year old 40 year old units from thirty different makes and models units from thirty different makes and models ere performed ere performed were performed were performed

KEY FINDINGS KEY FINDINGS KEY FINDINGS KEY FINDINGS

• The most important factor in

The most important factor in

• The most important factor in

The most important factor in preventing material degradation and preventing material degradation and i l i i th diti i l i i th diti ensuring long service is the condition ensuring long service is the condition

• f the insulating oil
• f the insulating oil
• Invasive maintenance is only required

Invasive maintenance is only required when significant degradation of the oil when significant degradation of the oil when significant degradation of the oil when significant degradation of the oil has occurred has occurred

Deterioration of Insulation Properties of Oil In Tank

Physical Properties (Condition) Contaminants Increasing Chemical Changes Decreasing A B C

Maintain Maintain

Time

Deterioration of Insulation Properties of Oil In Tank

Physical Properties (Condition) Contaminants Increasing Chemical Changes Decreasing A B C

Maintain

Weeks

Maintain

Time

Deterioration of Insulation Properties of Oil In Tank- Stage Two

Physical Properties (Condition) Contaminants Increasing Chemical Changes Decreasing A B C

Maintain

Years

Maintain

Time

Deterioration of Insulation Properties of Oil In Tank – Stage Three

Physical Properties (Condition) Contaminants Increasing Chemical Changes Decreasing A B C

4-5 years

Maintain

Time

STAGE C STAGE C - MAINTAIN MAINTAIN STAGE C STAGE C MAINTAIN MAINTAIN

• Relatively rapid aging process

Relatively rapid aging process

• Relatively rapid aging process

Relatively rapid aging process

 Moisture and acidity increase rapidly

Moisture and acidity increase rapidly Breakdown strength decreases significantly Breakdown strength decreases significantly

 Breakdown strength decreases significantly

Breakdown strength decreases significantly

• Maintenance

Maintenance

S f S f

 Should be completed before rapid

Should be completed before rapid degradation occurs degradation occurs UK i t ithi 8 UK i t ithi 8 10 10

 UK experience suggests within an 8

UK experience suggests within an 8-10 year 10 year period (typical maintenance cycle), failure can period (typical maintenance cycle), failure can

• ccur
• ccur
• ccur
• ccur

RESULTS CLASSIFICATION RESULTS CLASSIFICATION RESULTS CLASSIFICATION RESULTS CLASSIFICATION

• Pass = Satisfactory Condition

Pass = Satisfactory Condition

• Pass Satisfactory Condition

Pass Satisfactory Condition

 Retest at the next maintenance interval or 5 years

Retest at the next maintenance interval or 5 years (whichever is the shorter) (whichever is the shorter)

• Retest = Indication of Some Degradation

Retest = Indication of Some Degradation

 Unit should be maintained at 50% of maintenance interval or

Unit should be maintained at 50% of maintenance interval or 3 ( hi h i th h t ) 3 ( hi h i th h t ) 3 years (whichever is the shorter) 3 years (whichever is the shorter)

• Maintain = Advanced Degradation

Maintain = Advanced Degradation

Plan for Maintenance Within 6 Plan for Maintenance Within 6 Months Months

 Plan for Maintenance Within 6

Plan for Maintenance Within 6 Months Months

Immediate Action Immediate Action

Plan for Urgent Attention recommended no live switching Plan for Urgent Attention recommended no live switching

 Plan for Urgent Attention, recommended no live switching

Plan for Urgent Attention, recommended no live switching

SAMPLING SAMPLING SAMPLING SAMPLING

• Access is through the top of the tank using

Access is through the top of the tank using

• Access is through the top of the tank using

Access is through the top of the tank using a specially designed cover plate for test a specially designed cover plate for test probe access probe access probe access probe access

• Sampling can be performed live

Sampling can be performed live S li t b f d t i tl i S li t b f d t i tl i

• Sampling must be performed strictly in

Sampling must be performed strictly in accordance to established procedures and accordance to established procedures and id li i th t t i l id li i th t t i l guidelines using the correct materials guidelines using the correct materials

• The procedure is safe

The procedure is safe

LIVE TANK OIL SAMPLING LIVE TANK OIL SAMPLING (LTOS) (LTOS) (LTOS) (LTOS)

STATISTICS (NEDL STATISTICS (NEDL - UK) UK) STATISTICS (NEDL STATISTICS (NEDL UK) UK)

BASED ON 437 UNITS BASED ON 437 UNITS

Pass Pass Retest Retest Maintain Maintain

No Units No Units 382 382 37 37 8 8 % % 89.5 89.5 8.7 8.7 1.9 1.9

LTOS RESULTS LTOS RESULTS LTOS RESULTS LTOS RESULTS

NEDL (UK) : 437 units

9% 2% 89%

Pass R etest Maintain

New Zealand Experience New Zealand Experience New Zealand Experience New Zealand Experience

• Used by more then 6 Utilities ( Vector

Used by more then 6 Utilities ( Vector

• Used by more then 6 Utilities ( Vector

Used by more then 6 Utilities ( Vector Powerco Powerco etc) etc)

• Close to 700 Units Tested

Close to 700 Units Tested

• Close to 700 Units Tested

Close to 700 Units Tested

• Training and Retesting of plates by MHL

Training and Retesting of plates by MHL

• Approved Safety Procedures

Approved Safety Procedures

• Approved Safety Procedures

Approved Safety Procedures

• Results available in soft copy

Results available in soft copy

• L&C

L&C R ll R ll St tt St tt A d l t A d l t ABB SD ABB SD

• L&C ,

L&C , Reyrolle Reyrolle, , Statter Statter, , Andelect Andelect, , ABB SD ABB SD

LTOS RESULTS LTOS RESULTS LTOS RESULTS LTOS RESULTS

New Zealand :686 units

6% 5%

Pass 582 Retest 29 M i t i 43

4% 6%

Maintain 43 Immediate 32

85% 85%

$$ SAVINGS $$ SAVINGS $$ SAVINGS $$ SAVINGS

• Time based maintenance vs LTOS (less

Time based maintenance vs LTOS (less

• Time based maintenance vs LTOS (less

Time based maintenance vs LTOS (less units, less time) units, less time)

• Repair versus replacement

Repair versus replacement

• Repair versus replacement

Repair versus replacement

• Downtime

Downtime

• Collateral Damage and Repair

Collateral Damage and Repair

• Collateral Damage and Repair

Collateral Damage and Repair

• Environmental Costs

Environmental Costs

• R

l t Fi R l t Fi

• Regulator Fines

Regulator Fines

• Lost Revenue

Lost Revenue

THANK THANK-YOU YOU THANK THANK YOU YOU

• EA Technology

EA Technology gy gy