example of substation maintenance & assessment audits for training - niels inderbiethen
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Technical Report SAFE™ Audit of 3.3 & 11kV Switchoards
Substation name Customer Location
2014/01/09
Infrastructure & Cities Sector
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Table of contents 1. General information ...................................................................................................... 3
2. Chart of Medium voltage condition ............................................................................. 6
3. Summary ....................................................................................................................... 7
4. Safety ............................................................................................................................. 8
5. Visual inspection when asset in operation ............................................................... 15
6. Environmental sustainability ..................................................................................... 28
7. Maintenance recommendations ................................................................................ 29
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1. General information
Audit
Customer
Country South Africa
Location
Substation name
Asset type Audit of Siemens 11kV & 3.3kV 8BD
Type Siemens 8BD Panels 3AC / 3TL5
Serial number B4E213765
Date 2014/01/09
Remarks Audit for assessing life-time status
Auditor
Name Niels Inderbiethen
Department AFR RC-ZA IC-SG SE MCS
Telephone +27 (10) 222-7315
Fax
E-mail [email protected]
Customer data
Contact person (technical) card below
Telephone number of the contact person See below
Fax number of contact person As below
E-mail of contact person As below
Postal Code
Town
Street, No.
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Technical Information
Manufacturer Siemens
Type designation of switchgear Siemens RSA Type: 8BD 11kV 25kA with 3AC Circuit breaker & 3TL5 Contactor Trucks
Standard IEC 60298 / VDE 0670-6 (metall closed)
Year of manufacture of switchgear 1976
Substation arrangement Double busbar
Installation Indoor
Number of bays 15 (a mix of (4) ABB & rest Siemens
Number of spare bays A few may become available once plant redundancy is established
Serial numbers TBA
Air insulated metall closed switchgear Yes
Gasinsulated metall closed switchgear No
Remark The Panel is joggled onto an ABB panel of 4 tiers & shares the busbar system
General remarks by auditor It should be noted that some of these panel tiers seem to have come from different locations and are rather "fitted" (diferent colours of panel parts fitted together)
General remarks by customer There have been previous explosions on the board and there seems to have been a robbery of the copper on this panel the week before conducting the audit - all open & exposed copper was removed from panel leaving a very unsafe running condition
Rated voltage 12 kV
Rated lightning impulse withstand voltage 95 kV
Control voltage (DC/AC) DC
Control voltage 110 V
Rated short circuit breaking current 25 kA
Maximum busbar current 2000 A
Rated current supply 2000 A
Rated current feeder 1600 A
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Historical Information
Years of operation since first commissioning 36-40 years
Are maintenance reports available? No
Have circuit breakers been modified? Yes
When? Various occasions
Remarks Some circuit breakers are from other simillar panels from elswhere in Sasol
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2. Chart of Medium voltage condition (Weighted average of evaluated attributes. 0: very good --> 100: bad)
0
20
40
60
80
100Battery system
Busbars
Bushings
Circuit breaker
Condition of building
Current transformer
Grounding
Load-break switchLow voltage switchgearMeasurement
Metering
Natural
Ageing
Post insulators
Protection and
secondary system
Safety
Switchgear accessories
Voltage transformer
Maintenance requirements
Natural Ageing ████ Very critical attributes were found. Immediate action required.
Safety ████ Very critical attributes were found. Immediate action required.
Condition of building ████ Critical attributes were found. Repair or replace as soon as possible.
Switchgear accessories ████ Very critical attributes were found. Immediate action required.
Circuit breaker ████ Very critical attributes were found. Immediate action required.
Load-break switch ████ Very critical attributes were found. Immediate action required.
Grounding ████ Very critical attributes were found. Immediate action required.
Post insulators ████ Very critical attributes were found. Immediate action required.
Bushings ████ Very critical attributes were found. Immediate action required.
Busbars ████ Very critical attributes were found. Immediate action required.
Current transformer ████ Harmful attributes were found. Repair during next planned maintenance (monitoring).
Voltage transformer ████ Very critical attributes were found. Immediate action required.
Metering ████ Harmful attributes were found. Repair during next planned maintenance (monitoring).
Measurement ████ Harmful attributes were found. Repair during next planned maintenance (monitoring).
Prot & Secondary system ████ Very critical attributes were found. Immediate action required.
Low voltage switchgear ████ Harmful attributes were found. Repair during next planned maintenance (monitoring).
Battery system ████ Harmful attributes were found. Repair during next planned maintenance (monitoring).
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3. Summary
The condition of the panels can be seen in the pictures provided, the board would require to be cleaned and refurbished if wanted to be permanently left installed and still utilized. We would recommend a few procedures followed to ensure the safety of the existing equipment, a fully detailed compilation may be submitted with quotation upon request. These are more cost effective repair suggestions such as retro-fitting to vacuum, cleaning, facilitating remote operation & repair of any water leaks.
3.3kV & 11kV Panel general overview photo’s
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It would be recommended to possibly remove, clean and coat the busbars with ray-chem or resin for future protection. Breaker trucks can be retro fitted completly to vacum, wiring is still in good condition including termination points. Bus-chamber to be cleaned on surface and re-painted. Areas that show burning can be repaired by applying hay-site barriers over the effected & damaged areas. This would ensure the most cost effective manner of dealing with immediate problems and uplifting the safety and reliability factor of the whole board. It is also recommended that any redundant equipment should be considdered for removal to free up some spare space to fit new breakers & panels in the future. This could be done by possibly looking at the bus-section breaker as the split-point to one way or the other, by using cable to re-instate the connection in the trench to connect the panels again from the bus-section rear panel by cable termination to the continuation point in the existing board up to where panels are to be removed.
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11 kV (ABB – Sach‘e) - Panel photo’s – (note numbers differ
ABB Panel Joggle to Siem ABB 11 kV Panel -02 ABB 11 kV Panel -03 ABB 11 kV Panel -04 ABB 11 kV Panel -01
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SIEMENS - 11 kV Panel photo’s
11 kV Panel 01 11 kV Panel 02 11 kV Panel 03 11 kV Panel 04 11 kV Panel 05
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11 kV Panel photo’s (continued)
11 kV Panel 06 11 kV Panel 07 11 kV Panel 08 11 kV Panel 09 11 kV Panel 10
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11 kV Panel photo’s (continued)
11 kV Panel 11 11 kV Panel 12 11 kV Panel 13 11 kV Panel 14 11 kV Panel 15
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4. Safety
Staff protection
(NNB – It is important to state that these problems will no longer exist after retro-fitting)
Personnel protection insulation DIN VDE 0106 (IEC 60990)
Personnel protection insulation DIN VDE 0106 (IEC 60990) Bad, big impact deficiencies
Remark Equipment is in a very bad mechanical and functional condition - trips can no longer be fully relied upon
Operational safety DIN VDE 0101 (IEC 61936)
Load-break switch instead of disconnector Not applicable
Remark n/a
Switchgear interlocking unit Bad, big impact deficiencies
Remark Some Circuit Breaker Operating mechanism safety interlocks for the door to prevent opening under operating conditions seem to have a lot of play and replacement is advised
Operation from a safe distance Bad, big impact deficiencies
Remark Under the present condition operation is ONLY advised from a safe distance unless FULL Fire Protection is worn by operator and assistant - all others to leave the station
Installation of suitable electro-sensitive protective equipment Bad, big impact deficiencies
Remark There is literally a bird nest of wire and tangled cables under the full length of the panel inside the Cable Trench –some neatening of the cables & strapping of loose wiring is advised
Country-specific standards
Country-specific standards considered? Yes
Which kind of? The compliance to regulations for safe operations of Electrical plant and equipment need to be re-assessed in this substation due to the recent copper theft, which is also what has caused the untidy trenches etc.
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5. Visual inspection when asset in operation
Environment
Altitude of site 1000 m up to 2000 m
Ambient temperature range - 5 °C up to + 40 °C
Current temperature on substation site 28
Quality of the ambient atmosphere Dirty
Installation in seismic zone No
Remark the coal dust is visible on insulators in busbar chamber & any moisture from the cable-way may now pose serious electrical flashover threats
Building
outside
Ventilation, air exhaust louver, pick safety Bad, big impact deficiencies
Remark High humidity - no heaters are present in board
Pressure relief building Bad, big impact deficiencies
Remark The building is also not pressurized
inside
Aisle widths sufficient / escape route available good, no defects
Remark none
Floor, floor plates Bad, big impact deficiencies
Remark Some of the floor plates were removed during the cable theft incident as per photos
Cable basement, cable vault Bad, big impact deficiencies
Remark Wiring & cabling has been bundled up
Electro-installation, lighting Medium, insignificant deficiencies
Remark Seems ok - however a water leak was noted from the ceiling all the way down the wall by run-off tracks on the paintwork
Pollution, Humidity Bad, big impact deficiencies
Remark Coal dust - constant 90%+ permanent humidity – due to no heaters
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Switchgear accessories
Isolating protective plates VDE 0682-552 Bad, big impact deficiencies
Remark some have been stuck together with insulation tape
Guide strips for protective plates Bad, big impact deficiencies
Remark many guide plates have been damaged during the copper theft incident and some insulation plates have been broken
Grounding accessories VDE 683T100 Bad, big impact deficiencies
Remark All the copper external, on, or mounted to any switchgear or any bridged holding points was removed during theft - however this was immediately rectified by Client
Voltage tester VDE 682T411 Bad, big impact deficiencies
Remark The Voltage tester brought to test for isolation was not functional and could not be used
Fuse tongs VDE 681T3 Not applicable
Remark none
SF6-Maintenance unit available No
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Switching devices
First type of circuit breaker
Are circuit breakers installed? Yes
Principle of interruption Minimum oil
Number of circuit breakers 5 3AC type Circuit breakers and 3 type 3TL5 Vacuum contactors mixed in 8BD 11/3.3 kV Panel
Type designation of circuit breaker Various - but mostly feeders to plant transformers
Year of manufacture of circuit breaker 1976
Years of operation since first commissioning 36-40 years
Manufacturer Siemens
Serial numbers 31175637
Type of operating mechanism Manual operating mechanism
Type of bodywork Trolley
Control voltage (DC/AC) DC
Control voltage 110 V
Number of operations in accordance with the operation counter high
Diagnosis Bad, big impact deficiencies
Remark mechanisms of all circuit breakers are at the end of their lifecycle - trip failure experienced during inspection - loose adjustment & serious wear determined as cause / corrosion & rusted sliding surface issues found
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Second type of circuit breaker
Are circuit breakers installed? Yes
Principle of interruption Vacuum
Number of circuit breakers 3
Type designation of circuit breaker Siemens 3AC & 3TL5
Year of manufacture of circuit breaker 1976
Years of operation since first commissioning 36-40 years
Manufacturer Siemens
Serial numbers as per individual breakers
Type of operating mechanism Magnet drive
Type of bodywork Trolley
Control voltage (DC/AC) DC
Control voltage 110 V
Number of operations in accordance with the operation counter high
Diagnosis Bad, big impact deficiencies
Remark Corrosion & rust (all seem quite affected by this) however we must make mention that Sasol Nitro has 6 spare Contactors recently all refurbished - (as an emergencycontingent for spares)
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Third type of circuit breaker
Are circuit breakers installed? Yes
Principle of interruption Vacuum
Number of circuit breakers 4
Type designation of circuit breaker ABB / SACHE HA1/2c-17-12-20
Year of manufacture of circuit breaker Not Shown
Years of operation since first commissioning <20 years
Manufacturer ABB
Serial numbers ME063100
Type of operating mechanism Motor operated mechanism
Type of bodywork Plug - in board
Control voltage (DC/AC) DC
Control voltage 48 V
Motor voltage (DC/AC) DC
Motor voltage 125 V
Number of operations in accordance with the operation counter low
Diagnosis Medium, insignificant deficiencies
Remark The Sache breakers still look relatively in a good state, but the life expectancy may be crippled by dust, dirt & moisture if heaters are not present
Forth type of circuit breaker
Are circuit breakers installed? No
Remark none
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First type of load break switch
Are load break switches or fuses installed? Yes
Design Fuse mounting
Type of operating mechanism Manual operating mechanism
Number of load-break switches none (fitted are only fuses with striker pin mounting brackets on all contactor feeders)
Type designation of load break switch none
Year of manufacture of load-break switch none
Years of operation since first commissioning 36-40 years
Manufacturer Siemens
Serial numbers not visible on all
Control voltage (DC/AC) DC
Control voltage Other...
Which kind of control voltage? 30V DC
Number of operations in accordance with the operation counter N.A.
Diagnosis Medium, insignificant deficiencies
Remark Mainly affected by corrosion
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Second type of load break switch
Are load break switches or fuses installed? No
Remark None
First type of disconnector
Are disconnectors installed? No
Remark None
First type of earthing switch
Are earthing switches installed? Yes
Make proof earthing switch Yes
Type of operating mechanism Manual operating mechanism
Number of earthing switches not determinable
Type designation of earthing switch cable earth switches if fitted
Year of manufacture of earthing switch same as panel
Years of operation since first commissioning 36-40 years
Manufacturer Other...
Manufacturer Siemens Italy
Serial numbers not determinable
Diagnosis Cannot be determined – (these will be internally fitted if present)
Second type of earthing switch
Are earthing switches installed? No
Earthable fixpoints
Are earthable points installed? No
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Components
Post insulators
Are post insulators installed? Yes
Type Cast resin
Diagnosis Bad, big impact deficiencies
Condition Dirty
Remark Showing signs of hollow bubbling on surface - meaning they will start absorbing more moisture as time goes by - carbon & moisture is a dangerous combination & can become semi-conductive & flash-over
Bushings
Are bushings installed? Yes
Type Cast resin
Diagnosis Bad, big impact deficiencies
Condition Damaged
Remark some through-bushings from the C/B compartment into the live busbar chamber are broken or damaged
Busbars
Are busbars installed? Yes
Insulation Air insulated
Material Copper
Cross section 2 by 10
Diagnosis Bad, big impact deficiencies
Remark Bad corrosion / or carbon burning from prior explosions has discoloured & turned the copper black - insulators are covered in soot
Current rails
Are current rails installed? No
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Current transformer incoming feeder
Are current transformers installed? Yes
Design Post insulator instrument transformer
Insulation Cast resin
Type Current Electric
Year of manufacture assumed same as panel
Manufacturer Current Electric
Quantity several spread out among feeders, incomers, etc.
Serial numbers Name plates are taped to the LT compartment walls
Core data of 1st core (Example: 200/1 A, 15 VA, 5 P 20) as plates
Core data of 2nd core (Example: 200/1 A, 15 VA, 5 P 20) as plates
Core data of 3rd core (Example: 200/1 A, 30 VA, 1 Fs 5) as plates
Core data of 4th core (Example: 200/1 A, 15 VA, 5 P 20) as plates
Diagnosis Medium, insignificant deficiencies
Condition of current transformers Very dirty
Remark The CT's are old, however they may still remain operational for a long time, life-expectancy is cut by moisture problem without heaters
Current transformer outgoing feeder
Are current transformers installed? No
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Voltage transformer
Are voltage transformers installed? Yes
Design Conventional
Type 8BD - VT Ruksak
Year of manufacture same as panel
Manufacturer Siemens
Quantity 2 on the 11kV Board
Serial numbers not visible during operation
Primary voltage (Example: 110 000/√³ V) 11000
Secondary voltage of the measurement winding (Example: 110/√³ V) 110
Earth fault winding Yes
Class standard 11kV VT
Voltage factor (Example: 1.9 * Un, 4 h) standard
Diagnosis Bad, big impact deficiencies
Condition of voltage transformer Very dirty
Remark VT's are also advised to be checked and serviced regularly, especially from the coal / carbon residue
Surge Arresters
Are surge arresters installed? No
Over voltage limiter
Are overvoltage limiters installed? No
Secondary Systems
Metering
Is a counting facility available? Yes
Manufacturer various as per each panel LT relays mounted in relay compartment
Type also various
Diagnosis Medium, insignificant deficiencies
Remark The relays need to be checked & maintained annually, or it must be determined when last relay testing was conducted & the time for next testsshould be noted – testing of old protection is very important.
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Measurement
Is a measuring facility available? Yes
Manufacturer Various
Type KWH Relays
Diagnosis Medium, insignificant deficiencies
Remark The attention claim above refers to the need to check & maintain relays annually, or determining when last relay testing was conducted & the time for next tests
Protection
Are protection devices installed? Yes
Protection electromechanical
Distance Protection
Distance Protection No
Differential Protection
Differential Protection No
Over current protection
Over current protection Yes
Manufacturer Other
Manufacturer various
Type Over-current & Earth-fault
Diagnosis Bad, big impact deficiencies
Remark The earth-fault protection was non functional at the time of conducting the audit, due to all the earth bars having been loosened and removed by theft -this was all re-instated again in the same day by the client.
Busbar protection
Busbar protection No
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Low voltage switchgear
Are low voltage switchgear installed? Yes
Manufacturer various
Type LV 400V Isolators & feeder circuit MCB's
Year of manufacture unknown
Personnel protection insulation in accordance with DIN VDE 0106 (IEC 60990)
Yes
Diagnosis Medium, insignificant deficiencies
Remark The equipment is operational although old
Battery system
Do DC auxiliary supply equipment exist? Yes
Manufacturer various
Type various
Year of manufacture various
Diagnosis Medium, insignificant deficiencies
Remark equipment operational, it should also be tested once annually & any faulty units should be replaced
Compressed air generation
Is a compressed air generation available? No
Other
Other none
Documentation
Documentation
Documentation Not available/not installed
Remark Only the single line drawing was found in the substation, a full set of drawings should usually be available and checked that they are up to date
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Files
Attach file 1 All ABB Panel Pics.ZIP
Attach file 2 All Zips here combined for Report.rar
Attach file 3 Siemens 8BD Panel 01.zip
Attach file 4 Siemens 8BD Panel 02.zip
Attach file 5 Siemens 8BD Panel 03.zip
Attach file 6 Siemens 8BD Panel 04.zip
Attach file 7 Siemens 8BD Panel 05.zip
Attach file 8 Siemens 8BD Panel 06.zip
Attach file 9 Siemens 8BD Panel 07.zip
Attach file 10 Siemens 8BD Panel 08.zip
Attach file 11 Siemens 8BD Panel 09.zip
Attach file 12 Siemens 8BD Panel 10.zip
Attach file 13 Siemens 8BD Panel 11.zip
Attach file 14 Siemens 8BD Panel 12.zip
Attach file 15 13_14&15.zip
Audit Configuration
The first level of the audit is complete. How do you want to proceed? -The customer requests FUTURE consulting or thorough investigations / recommendations for retro-fits
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6. Environmental sustainability Conclusion
Important status parameters of the tested system indicate high risk of environmental hazard. Please observe the maintenance recommendations.
The board has suffered many explosions and requires a good cleanout and repainting or re-spraying. The busbar chamber needs urgent attention as carbon & coal dust have collected on all bars. There also seem to be a few connections where tape is coming loose and these are starting to find their way close to other phases or earth potential points. Many smaller problems exist as can be seen via the wiring in cable trenches and melted truncking that should be cleaned, neatened and replaced. This work could easily be undertaken in a very quick manner to tick off all problem areas. Circuit breaker mechs must be sprayed with lubrication every month from now going forward.
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7. Maintenance recommendations Safety Personnel protection insulation DIN VDE 0106 (IEC 60990) - The located weakpoints regarding personnel protection insulation have to be removed immediately Operational safety DIN VDE 0101 (IEC 61936) - The located weakpoints have to be removed immediately Natural Ageing - The actual ambient conditions may require additional maintenance works Condition of building outside - The located weakpoints on the building have to be removed immediately inside - The located weakpoints on the building have to be removed immediately - The located weakpoints on the building have to be removed on the next occasion Switchgear accessories - Exchanging equipment (start planing for older equipment exchanges) - Exchanging equipment (Check enough critical spares are still on hand to have sufficient time to implement) - Exchanging equipment (after anual testing, if found faulty, exchange with new as necessary or advised) - Exchanging equipment (circuit breakers can easily be exchanged (oil fire hazzard) rather for new vacuum) Circuit breaker First type of circuit breaker Maintenance of all the existing 3AC minimum-oil breaker operating mechanism, regular checks will be required (at least once a month) to ensure safer operation capability of the tripping coils as their operation has become hindered, leading to the posibility of an extensive delay in the effected breaker trip time. Should this scenario occur at the time of an electrical system fault, it may not trip in time &flash to the weakest point. Second type of circuit breaker - Maintenance of operating mechanism.
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Post insulators - Maintenance of insulators. Bushings - Maintenance of insulators. Busbars - Maintenance of insulators. Current transformer Current transformer incoming feeder - Maintenance of the equipment Voltage transformer - Maintenance respectively repair of the instrument transformer 1
Please note: This audit report summarizes only the existing condition of the customer’s electrical equipment and system at the time when the audit was performed. Please note that any subsequent changes of the equipment, system or equipment’s operation may cause inconsistency between the report’s summary and the subsequently changed conditions. Siemens cannot be held liable for such inconsistency. Charts, diagrams and graphics in this report are merely illustrations to summarize and to provide an overview of the condition of the customer’s electrical equipment and system at the time the audit was performed. No conclusions should be made and no further measures should be taken based exclusively on the graphic presentations included in this report. Siemens shall not be liable if the information included in this report is not handled or otherwise used with the necessary expert knowledge and thereby damage of any kind is caused. Siemens shall not be held liable for technical developments which supersede or invalidate the information in the report, if these could not have been reasonably known or identified prior to the time when the audit was performed.