MANUAL
DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
Title:
Distribution Task Manual – Part 11
CIRCUIT BREAKER: DELLE /
ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM:BLR, BLRM & BLRME
COMPILED BY
APPROVED BY
Unique Identifier:
Document Type:
Revision:
Published date:
Total pages:
Review date:
FUNCTIONAL RESP
34-960
DMN
0
FEBRUARY 2009
26
FEBRUARY 2014
AUTHORISED BY
_ _ _ _ _ _ _
SJ FABER/
DM NTOMBELA
_ _ _ _ _ _ _
A PERSADH
_ _ _ _ _ _ _
CD SMITH
_ _ _ _ _ _ _
MN BAILEY
Compiler
Switchgear Care
Chairperson
for TESCOD
DTM for MD (D Div)
DATE: 09 Dec 2008
DATE: 09 Dec 2008
DATE: 27 Jan 2009
DATE: 28 Jan 2009
WG
Content
Page
Foreword...................................................................................................................................................... 2
Introduction .................................................................................................................................................. 3
1
Scope .................................................................................................................................................. 4
1.1 Purpose.................................................................................................................................... 4
1.2 Applicability .............................................................................................................................. 4
1.3 Roles and Responsibilities....................................................................................................... 4
2
Normative/Informative References...................................................................................................... 5
2.1 Normative................................................................................................................................. 5
2.2 Informative. .............................................................................................................................. 5
3
Definitions And Abbreviations ............................................................................................................. 5
3.1 Definitions ................................................................................................................................ 5
3.2 Abbreviations ........................................................................................................................... 5
4
Requirements ...................................................................................................................................... 5
4.1 First and Second Line Maintenance ........................................................................................ 5
4.2 Specialist Maintenance ............................................................................................................ 6
4.3 Modifications ............................................................................................................................ 20
5
Testing................................................................................................................................................. 20
6
Related/Supporting Documents .......................................................................................................... 20
6.1 Related Documents.................................................................................................................. 20
6.2 Forms and Records.................................................................................................................. 20
7
Spares ................................................................................................................................................. 20
Annex A-Circuit-breaker report.................................................................................................................... 21
Annex B - Impact assessment..................................................................................................................... 23
JF Scholtz / Feb 2009 Rev 0
DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
2 of 26
Foreword
This Task manual was compiled to document the tasks procedure of maintaining DELLE / ALSTOM’S
CIRCUIT BREAKERS of types HG 710 and HG 720, rated at 33KV and 1250A with BLR, BLRM or
BLRME MECHANISMS to ensure that maintenance tasks are carried out in a safe manner. This Task
manual supersedes all previous work instructions / maintenance procedures on HG 710 and HG 720 with
BLR series mechanisms.
DELLE / ALSTOM HG 710 AND HG 720 BREAKERS
Revision history
This document cancels document SCSINAAV0.
Date
SEPTEMBER
2005
JANUARY 2007
Rev.
no.
0
Clause
Remarks
-
Compiled By: DM Ntombela
Original issues as SCSINAAV0
0
-
Compiled By: SJ Faber /DM Ntombela
The template / format and ref. number changed
Revision date.
2
3
-
Normative references updated;
Definitions and abbreviation updated;
Re-numbered all the titles and added more information
Included Revision History information;
-
Included impact assessment form; and
When downloaded from the DT WEB, this document is uncontrolled and the responsibility rests with the user
to ensure it is in line with the authorised version on the WEB.
DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Date
FEBRUARY 2009
Rev.
no.
Clause
0
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
3 of 26
Remarks
-
Reference number changed to DMN_34-960
-
Work instruction naming changed to Task manual
-
Document approved as DMN_34-960
Authorisation
This document has been seen and accepted by:
Name
Designation
MN Bailey
Corporate Manager Divisional Technology
C Smith
TESCOD
A Persadh
Switchgear Care WG Chairperson
SJ Faber / DM Ntombela Compiler
Development team
This Task manual was previously prepared by:
J.H. Coetzer
A.M. Jacobs
E. Mutloane
D. Ntombela
J. Richter
C.D. Smith
T. Stoffberg
H.Z. Strzalkowski
C. Troskie
K. van Coller
H. van der Westhuizen
And was revised by:
DM Ntombela
J Wilson
S Bouwer
J Ramoroka
E Mandavha
SJ Faber
Introduction
The Task Manual has replaced the Work Instructions within the Distribution Division. This has been done
to assist the end users of these documents and the following is important to note:
•
The contents of a Task Manual are always linked to the requirements of one or more Job Plans. In
many instances only selected paragraphs / sections of the Task Manual will apply to a specific Job
Plan.
•
Task Manuals also form the main content of the training module for the task and therefore only people
who have attended the training and assessed as competent should be assigned the task as described
in the Task Manual.
This Task manual is the revision of the document that was initially compiled and titled CIRCUITBREAKERS: DELLE / ALSTOM, TYPE: HG 710 & HG 720, MECHANISM: BLR, BLRM & BLRME,
RATINGS: 33kV; 1250A to formalize the procedures of performing tasks when carrying maintenance tasks
out. The document includes the latest updates in information, format, diagrams to make the document
more user-friendly and safety precautions.
When downloaded from the DT WEB, this document is uncontrolled and the responsibility rests with the user
to ensure it is in line with the authorised version on the WEB.
DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
4 of 26
Key words
Specialist Maintenance, Tools, Equipment, Personal Protective, circuit-breaker, Fixed contact, HG 720,
HG 710, Arc control device, Moving contact, Transfer contact, Re-assembly, External mechanism, Testing
Bibliography
Manufacturer’s manual.
1
Scope
1.1
Purpose
The purpose of this Task manual is to standardise maintenance instructions on DELLE / ALSTOM
CIRCUIT-BREAKERS, TYPE HG 710 and HG 720 with BLR series MECHANISM and rated 33kV; 1250A.
1.2
Applicability
This document is applicable to Eskom Distribution Division and all contractors working for distribution
division.
1.3
Roles and Responsibilities
1.3.1
Plant Managers shall be responsible for:
a)
Ensuring that equipment job plans are available and issued for specific maintenance.
b)
Ensuring that the maintenance feedback information that is available in the maintenance
management system is analysed.
1.3.2
Each Field Services Manager shall be responsible for:
a)
Ensuring that staff carrying out maintenance tasks is trained, competent and authorized to
perform maintenance on the specific equipment;
b)
Ensuring that instructions are implemented and adhered to and equipment is maintained in
accordance to relevant Task manuals.
c)
Ensuring that the maintenance feedback information / data is captured and recorded into the
system for future maintenance planning.
1.3.3
Electricity Delivery Manager shall be responsible for:
a)
Ensuring that trained, competent and authorized staff is available to perform maintenance / tests
on equipment out on maintenance when scheduled;
b)
Ensure that the relevant EDM section is available on site to isolate the equipment AC / DC
supply.
When downloaded from the DT WEB, this document is uncontrolled and the responsibility rests with the user
to ensure it is in line with the authorised version on the WEB.
DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
2
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
5 of 26
Normative/Informative References
Parties using this document shall apply the most recent edition of the documents listed below:
2.1
Normative
Occupational Health and Safety Act and Regulations (OHSAct).
NRS079-1: Mineral Insulating Oils.
ESKASABT0 (EST_32-332): Rev. 0, Oil spill clean-up and rehabilitation.
ESKPVAEY6: Rev. 0, Operating Regulations for High Voltage Systems.
DISASAAT8 (DST_34-1710): Rev. 4, Provision and use of Personal protective equipment.
SCSPBAAY2 (DPL_34-1005): Rev. 0, Environmental management policy.
SCSASAAX4 (DST_34-1451): Rev. 2, Standard for the maintenance of circuit-breakers and oil immersed
isolators.
DPC_34-444: Rev. 0, Procedure for the application and maintenance of portable earth’s.
SCSPVABF4 (DPC_34-908): Rev. 0, Procedure for Barricading.
DPC_34-227: Rev. 0, Pre-Task Planning and feedback process.
Manufacturers manual.
2.2
Informative.
DST_34-04: TESCOD framework
3
Definitions And Abbreviations
3.1
Definitions
All definitions in ESKPVAEY6 and OHSAct 85 of 1993 are applicable.
3.2
Abbreviations
PCB: Polychlorinated Biphenyls.
CDP: Career Development Programme;
PTO: Principal Technical Officer;
STO: Senior Technical Officer;
TO: Technical Officer; and
CCC: Change Control Committee.
4
Requirements
4.1
First and Second Line Maintenance
a)
Insulators shall be inspected for cracks or burn marks.
b)
Pollution levels on fibre insulators shall be monitored.
When downloaded from the DT WEB, this document is uncontrolled and the responsibility rests with the user
to ensure it is in line with the authorised version on the WEB.
DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
6 of 26
c)
There shall be no oil leaks - if any leaks are found these shall only be repaired by authorised
personnel.
d)
All gauge glasses shall be clear and legible.
e)
All oil levels shall be at the level mark - there shall be maximum and minimum level marks on all
oil gauge glasses
f)
Mechanism boxes shall be clean and dust free - checks shall be made for any general or
obvious defects.
g)
Mechanism box door and cover seals shall be intact.
h)
Mechanism heaters shall be operational - if a thermostat is fitted the cut out shall be set at
approximately 250C.
i)
The operating label shall be securely mounted and shall be legible from the operating position.
j)
All metal work shall be checked for corrosion or rust.
k)
The earth straps shall be in a good condition and effectively connected.
l)
All feeder advances shall be recorded as fault trips or operations.
NOTE: All defects found are to be reported to the Work Management Centre with the work order feedback.
4.2
Specialist Maintenance
4.2.1
Pre-Planning
4.2.1.1
Spares and Materials
a)
Approved lubricant;
b)
Approved electrical cleaner;
c)
Lint free cloth;
d)
Upper insulating cylinder "O"ring gaskets;
e)
Oil filling plug gasket;
f)
Upper case gasket;
g)
Sheath for upper contact fingers;
h)
Oil level indicator gaskets;
i)
Contact fingers;
j)
Contact tip and contact rod;
k)
Arcing ring;
l)
Pole cover gasket;
m)
Lower insulating cylinder gaskets;
n)
Tripping damper gasket;
o)
Drain cock gasket;
p)
Bearing covers gaskets;
q)
Mechanism shaft gasket;
r)
Shaft gasket and.
When downloaded from the DT WEB, this document is uncontrolled and the responsibility rests with the user
to ensure it is in line with the authorised version on the WEB.
DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
s)
Split pins:
4.2.1.2
Tools and Equipment
a)
Micro ohmmeter;
b)
Standard set of tools;
c)
Mechanism operating lever/tool ;
d)
Scaffolding/Ladder;
e)
a 5 kV insulation tester;
f)
1 x empty drum;
g)
Cleaning tray;
h)
Portable oil pump and hose with fittings;
i)
Grease gun; and
j)
Speed tester.
4.2.1.3
Personal Protective Equipment
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
7 of 26
All personal protective equipment shall be in accordance with DISASAAT8 and shall include those identified during
risk assessment (DPC_34-227).
a)
Overall;
b)
Hard hat;
c)
Safety boots;
d)
Fall Arrest System (where necessary);
e)
Gloves.
4.2.2
Safety and Preparation
a)
Isolate and earth panel in accordance with ESKPVAEY6.
b)
Erect barricading in accordance with SCSPVABF4.
c)
Erect scaffolding/ladder (where required).
d)
Ensure all tools, equipment and materials are placed inside the barricaded area and where they
will not hinder or obstruct any worker or the entrance.
e)
Manually close and open the circuit-breaker from the mechanism box to discharge springs.
f)
Environmental hazards shall be removed in accordance with SCSPBAAY2 and ESKASABT0
g)
Isolate the D.C. supply to the panel to prevent accidental closing or tripping of the circuitbreaker.
h)
Ensure that circuit-breaker is isolated in terms of ESKPVAEY6 and any LV supply is switched
OFF before commencing with the next steps.
When downloaded from the DT WEB, this document is uncontrolled and the responsibility rests with the user
to ensure it is in line with the authorised version on the WEB.
DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
4.2.3
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
8 of 26
Maintenance
Risk assessment and critical task analysis shall be done in accordance to DPC_34-227 and approved
safe work procedures before the commencement of work.
4.2.3.1
Opening the circuit-breaker
a)
Ensure that the correct circuit-breaker has been OPENED, ISOLATED and EARTHED as per
ESKPVAEY6 and check the status indicator on the mechanism door to be indicating OFF.
b)
Where the moving contact is to be replaced, close the circuit-breaker and remove fuses or
switch the D.C. supply to the panel OFF.
c)
Ensure that under no circumstances will any person start to work on the mechanism while the
trip spring is still charged and proceed to step f).
d)
Where the moving contact is not going to be replaced, close the circuit-breaker, remove or
switch the D.C. supply to the panel OFF to prevent accidental closing or tripping of the circuitbreaker.
e)
Before draining the oil, manually perform an open – close - open operation to discharge the
closing springs in the operating mechanism (refer to step b) and see figure 1).
f)
Ensure that the circuit-breaker is in an open position before commencing with maintenance
(refer to step b) and see figure 1).
Figure 1
g)
Loosen and remove the drain plug, attach the draining hose onto the draining valve and the oil
pump.
h)
Loosen and remove the explosion chamber securing screws and remove it from the pole head.
i)
Open the oil drain valve (where applicable), start the oil pump and drain the dirty oil into the
empty drum (see figure 2).
When downloaded from the DT WEB, this document is uncontrolled and the responsibility rests with the user
to ensure it is in line with the authorised version on the WEB.
DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
9 of 26
Figure 2
j)
Inspect the gas exhaust opening grate and the vent to be clean and free from blockages.
k)
Also inspect the safety valve and oil return valve to be free from blockages, clean with electrical
cleaner and rinse with oil.
l)
Check the explosion chamber gasket for cracks and any physical damage, replace it with a new
one during re-assembly.
m)
Loosen and remove the jumper connection bolts for the upper terminal and lower terminal and
secure the jumper at a safe position (see figure 3).
n)
Loosen and remove the upper case securing bolts and remove the upper case (see figure 3).
Figure 3
o)
Loosen and remove the gauge glass securing bolts, remove the gauge glass and the gaskets
(see figure 4).
p)
If the gauge glass housing is dirty, it must be cleaned with approved electrical / hand cleaner
and painted with white paint where necessary.
q)
Inspect the gauge glass and the securing gauge glass holder for cracks and any physical
damages and replace them with new ones if necessary (see figure 4).
When downloaded from the DT WEB, this document is uncontrolled and the responsibility rests with the user
to ensure it is in line with the authorised version on the WEB.
DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
10 of 26
Figure 4
r)
Re-fit the gauge glass gaskets (new one), gauge glass and the gauge glass securing
holder/flange and tighten the securing screws.
s)
Check the upper case gasket for cracks and any physical damages.
4.2.3.2
Fixed contact
NOTE: In case of type HG 720 the fixed contacts-assembly and explosion pot are attached to expansion chamber and the
fixed contact will only be exposed after removing the explosion pot.
a)
b)
c)
For HG 720
•
Loosen and remove the expansion chamber securing screws, remove the expansion
assembly and place it on the cleaning tray.
•
Loosen and remove explosion chamber / arc control device securing screws and remove it
from the expansion chamber / fixed contact assembly.
•
Loosen and remove the fixed contacts-assembly holding screws and remove the assembly
from the expansion chamber for inspection and maintenance.
For HG 710
•
Loosen and remove the expansion chamber securing screws, remove the expansion
assembly and place it on the cleaning tray.
•
Loosen and remove the fixed contacts-assembly securing screws and remove the assembly
from the expansion chamber for inspection and maintenance.
Inspect the fixed contacts and the arcing rings for pitting, burn marks, carbon deposits and any
physical damages (see figure 5).
Figure 5
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to ensure it is in line with the authorised version on the WEB.
DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
d)
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
11 of 26
Should the fixed contact fingers and the arcing rings be damaged the following steps shall be
followed to dismantle the fixed contact assembly:
•
Remove the arcing ring by inserting a rod (20mm for HG 710 and 22mm for HG 720) in the
fixed contact.
•
Loosen and remove the arcing ring from the finger contacts protecting sheath.
•
Unscrew and remove the protecting sheath, remove the fixed contact fingers and extract the
rod.
e)
Clean the contact-fingers and the arcing ring with electrical cleaner and scourer, and examine
their condition.
f)
Measure the diameter of the arcing ring bore and it must not exceed 28mm for HG720 and
26mm for HG710 and replace the damaged ring with the new one (see figure 6).
Figure 6
g)
Measure the remaining contact surface of the finger contacts, the remaining contact surface
must not be less than 15mm for HG720 and HG710 and replace the damaged contacts with the
new one (see figure 7).
h)
In reverse order assemble the new finger contacts onto the contact holder.
Figure 7
When downloaded from the DT WEB, this document is uncontrolled and the responsibility rests with the user
to ensure it is in line with the authorised version on the WEB.
DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
12 of 26
i)
Re-fit the protective sheath over the finger contacts and screw it onto the contact holder, insert
the appropriate rod into the fixed contact and screw the arcing ring onto the sheath.
j)
Assemble the fixed contact assembly onto the upper case.
4.2.3.3
Arc control device (Turbulator/Explosion pot)
a)
When type HG 720 is being maintained:
b)
•
And the explosion pot / arc control device has been remove from the expansion chamber,
proceed with / to step c).
•
But if it has not been removed from the expansion chamber or the circuit-breaker head,
loosen and remove expansion chamber securing bolts and lift the assembly from the pole
and place on the cleaning tray.
•
Loosen and remove the explosion chamber securing screws and remove it from the
uppercase and proceed to step c).
When type HG 710 is being maintained:
•
Loosen and remove the upper insulating cylinder holding bolts and remove the cylinder
(refer to figure 6).
•
Loosen and remove the explosion pot holding screws and remove the explosion pot.
c)
Place the explosion pot in a cleaning tray and clean or wash it with insulating oil.
d)
Inspect the explosion pot for burn marks, cracks, carbon deposits and any physical damages
(see figure 8).
Figure 8
e)
If the explosion pot is badly damaged replace it with a new one.
4.2.3.4
Moving contact
a)
With the explosion pot removed the moving contact will be exposed (see figure 9 (6)).
When downloaded from the DT WEB, this document is uncontrolled and the responsibility rests with the user
to ensure it is in line with the authorised version on the WEB.
DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
13 of 26
Figure 9
List of Parts on the figure 9 above:
1.
Gasket for filling plug.
20. Arcing ring of upper fixed contact
2.
Gas expansion chamber.
21. Explosion pot.
3.
Upper case.
38. Gasket for lower insulating cylinder
(27) (2 gaskets).
39. Clamping bolts of lower insulating
cylinder (27) (2 SCREWS +6
BOLTS).
4.
Safety valve.
22. Moving contact rod (conducting
portion).
5.
Upper terminal: – pad for HG 710.
pad for HG 720
23. Lower sliding contact finger (8 finger
for HG 710 and 10 for HG 720).
6.
Arcing tip of moving contact rod (22).
7.
Un-used number.
24. Set screws of upper and lower
insulating cylinders (8 and 27) (8
screws).
8.
Upper insulating cylinder
(extinguishing chamber).
25. Centring elastic pin (HG 710) (2
pins).
9.
Explosion pot support (for HG 710).
26. Insulating extension of moving
contact rod (22).
44. Gasket for tripping damper (32).
27. Lower insulating cylinder.
46. Gasket for drain cock (33).
28. Tie rod (2 tie rods)
47. Gasket for bearing cover (50).
29. Mechanism case.
48. Mechanism shaft
30. Centring elastic pin (4 pins for HG
710).
49. Gasket for mechanism shaft (48).
31. Set screw of upper case (3) (8
screws).
51. Gasket for bearing cover (52).
10. Lower sliding contact – lower
terminal.
11. Guide for moving contact rod (22)
(2guides).
12. Filling plug.
13. Set screw of expansion chamber (2)
(6 screws).
14. Gasket between expansion chamber
(2) and upper case.
15. Oil return valve.
16. Gasket for oil level indicator.
17. Oil level indicator.
18. Finger protective sheath.
19. Upper contact finger (8 fingers for
HG 710 and 10 for HG 720).
32. Tripping damper.
33. Pole drain cock.
34. Gas exhaust and vent opening.
35. Gas exhaust jet.
36. Gasket for upper insulating cylinder
(8) (2 gasket).
37. Upper fixed contact holder.
40. Un-used number.
41. Stop screw to secure guide (11) (2
screws).
42. Damper guide of moving contact rod
(22).
43. Base plate of guides (11).
45. Mechanism arm
50. Bearing cover (shaft exit side).
52. Bearing cover (opposite to shaft exit
side).
53. Finger protective sheath (lower
sliding contact (23)) (HG 720).
54. Tie-rod connecting pin (with damper
guide portion of contact rod (42)).
NOTE: Gasket 36 and 38 are identical
in breakers HG 710.
When downloaded from the DT WEB, this document is uncontrolled and the responsibility rests with the user
to ensure it is in line with the authorised version on the WEB.
DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
14 of 26
b)
Clean the moving contacts arcing tip and the rod with electrical cleaner and scourer.
c)
Inspect the contact arcing tip for burn marks, carbon deposits and any physical damages (refer
to figure 9 (6)).
d)
Should the contact arcing tip be heavily damaged replace it with the new one.
e)
To remove the contact arcing tip, use the square wrench to unscrew it (excessive force should
not be applied without supporting or holding the contact rod with pliers).
f)
Ensure that the insulating extension part of the rod is free from cracks and any physical
damages (refer to figure 9 (26)).
g)
Replace the contact arcing tip with the new one and tighten it.
4.2.3.5
Transfer contact
a)
To inspect the transfer contact:
b)
•
Remove the lower insulating cylinder by loosening and removing holding screws; and
•
Remove the lower insulating cylinder (see figure10).
Inspect the transferring contact fingers for burn marks, carbon deposits and any physical
damages (in case of HG 720 a protective sheath has to be removed first and explosion port
support has to be removed on type HG 710) (see figure 10 & refer to figure 9 (23)).
Figure 10
c)
Should the transferring contact fingers be badly damaged, replace them with the new ones.
d)
To replace the contact fingers on HG 720 follow the next steps:
e)
•
Loosen and remove the transfer contact assembly securing screws and remove the
assembly from the flange.
•
Remove the protective sheath from the contact assembly.
•
Disassemble the finger contact cluster assembly and replace the finger contact with new
ones.
To replace the contact fingers on HG 710 follow the next steps:
•
Loosen and remove the explosion support securing bolts / screws and remove the explosion
pot / arc control device.
•
Loosen and remove the transfer contact securing screws / bolts and remove the transfer
contact assembly.
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DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
•
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
15 of 26
Disassemble the finger contact cluster assembly and replace the finger contact with new
ones.
f)
Inspect the tie rod and the levers in the crank casing for any wear and cracks, and replace the
damaged parts with ones.
g)
Assemble the transferring contact fingers cluster onto the flange and tighten the securing
screws.
4.2.3.6
Re-assembly
a)
Re-fit the explosion pot assembly for type HG 710 and tighten the support holding screws and in
case of type HG 720 re-fit the protective sheath and tighten the securing screws.
b)
Re-fit the lower insulating cylinder into position, insert the holding bolts and tighten the bolts.
c)
Refit the upper cylinder onto the lower cylinder and tighten the securing screws / bolts.
d)
For type HG 710 assemble the fixed contact assembly onto upper case, tighten the contact
assembly holding screws.
e)
For type HG 720 assemble the fixed contact assembly, the explosion pot and the upper casing
and tighten the securing screws / bolts.
f)
Re-fit the upper casing assembly onto the upper cylinder and tighten the securing bolts.
g)
Flush all poles with approved insulating oil, allow oil to drain and close the drain valve (where
applicable).
h)
Remove the drain hose and the oil pump and re-fit the draining plug.
i)
Fill all poles with approved insulating oil, re-fit the expansion chamber and tighten the securing
screws.
j)
Clean the external surface of the circuit-breaker with electrical cleaner and wipe it clean with lint
free cloth.
4.2.3.7
External mechanism
a)
Ensure that all springs are still discharged before commencing with any work.
b)
Clean the pivots and the linkages with electrical cleaner and a paint-brush.
c)
Inspect the pivots and the linkages for wear, rust and any mechanical damages (see figure 11).
Figure 11
d)
Should any of the parts be worn or damaged it must be replaced with a new one.
e)
Lubricate all pivots with approved lubricant and spray the linkages with approve lubricant.
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DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
4.2.3.8
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
16 of 26
Mechanism
NOTE: The mechanism shall not be operated when it is not linked to circuit-breaker as this could lead to rupture or
complete destruction of some parts of the mechanism.
NOTE: When cleaning parts composing of sealed bearings (unless the bearings are to be replaced) with electrical
cleaner ensure that the solvent does not penetrate the bearing as it will dissolve and remove the bearing grease.
a)
Ensure that the circuit breaker is switched off and the mechanism is discharged (closing spring
is indicated as free) by manually OPENING, CLOSING and OPENING the circuit-breaker.
b)
If the circuit-breaker is closed "open-close-open" the circuit-breaker to discharge the springs and
if the circuit-breaker is open "close-open" to ensure that the springs are discharged.
c)
Loosen and remove the operating mechanism cover securing screws and remove the
mechanism cover (see figure 12).
Figure 12
d)
Clean dust and excessive grease deposits from the mechanism.
e)
Check and ensure that the trip and close plungers are free to move and are not bent.
f)
Inspect the operating mechanism parts (chains, cams, sprockets, lever, links etc.) for wear and
rust, and check the springs for rust and tension loss (deformation) (see figure 13).
g)
Replace the damaged parts with new ones, and lightly lubricate drive levers, sprockets, rollers,
drive chains etc with Vactra no 3 oil from Mobile (see figure 13).
Figure 13
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DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
17 of 26
h)
Also apply a thin layer of grease over the closing and opening springs (see figure 14).
i)
Lubricate all the cams with Vélocité oil no.10 from Mobile or Vaseline from Mauny (see figure
14).
j)
Use S A E 90 to lubricate sprockets and chains and use silicone oil to lubricate pins, rollers,
lever hinges, tie-rods and springs (see figure 14).
Figure 14
NOTE: While cleaning and lubricating ensure that the cleaning materials and lubricants is prevented from going into
the auxiliary switches.
k)
Clean the terminal blocks and auxiliary contacts, check that all electrical connections are tight,
clean any oil drops on them and spray them with moisture repellent spray (see figure 15).
Figure 15
l)
To check the spring rewind motor brushes loosen and remove the brushes securing cap (on old
equipment), unclip the plastic stopper (new equipment), remove the brushes, check the length
of the brushes and inspect the commutator segments for excessive wear, short circuits and
carbon build-up in between.
m)
Where the commutator segments are damaged, replace the motor (replace the
commutator/rotor if available) with new one and where only brushes need to be replaced, clean
carbon off the commutator with approved electrical cleaner, scourer and a brush and re-fit the
brushes into position (see figure 16).
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DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
18 of 26
Figure 16
n)
To replace the motor label motor-supply wires (where necessary) and disconnect the motor
supply wires.
o)
Support the motor, loosen and remove the motor fixing screws, unhook the rubber drive belt and
remove the motor (see figure 17).
p)
Loosen and remove cap screw (Allen screw) securing the pulley onto the shaft and remove the
pulley form the shaft.
q)
Examine the drive belt for cracks and replace it with a new one where necessary, check the cam
belt for wear, cracks or excessive slack and replace if it is necessary (see figure 17).
Pulley
Rubber Drive Belt
and the drive
pulley
Figure 17
r)
Check the anti-condensate heater to be in working order, if not repair or replace it with a new
one (see figure 8.
Figure 18
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DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
19 of 26
s)
Check the resistance of the closing, tripping and backup tripping coils, record the reading for
future references and inspect the coils for any physical damages i.e. insulation breakdown,
sticking plungers.
t)
Should any of the coils or part of the solenoid assemblies are damaged replace it with a new
one by label the supply wires, disconnecting it and replacing it.
u)
Measure the core travel (must be 11mm wide), loosen and remove securing screws and remove
the coil from the support plate / bracket.
v)
Clean the solenoids assemblies mounting place with electrical cleaner and the scourer, mount
the new solenoid onto support plate / bracket and loosely tighten the securing screws (see
figure 19).
w)
Check the travel core gap to be 11mm, adjust the gap when it is necessary, tighten the solenoid
assembly securing screws and apply a little bit of locktite adhesive on the securing nuts.
x)
Ensure that the plunger rod clears the tripping lever by 2mm if not, loosen the assembly
securing screws (8mm screws), adjust the gap and tighten the screws and nuts and apply the
locktite again.
y)
Where it is necessary to replace the stop screw, ensure that ONLY ALUMINIUM SCREW is
used and NO STEEL SCREWS shall be used as a stop screw.
z)
The steps p) to s) must be followed in replacing tripping and backup coils and it shall be ensured
that the upper solenoid’s core is directly against the lower solenoid’s push rod (see figure 19).
Figure 19
aa)
To replace under voltage coil and micro switches (where applicable) mark the supply wires and
disconnect them.
bb)
Loosen and remove the securing screws and remove the coil or the micro switch and replace
them with new ones.
cc)
To replace the anti-pumping relay mark the wires, remove the wires, unclip the relay from the
tray and remove it.
dd)
Refit and re-connect the anti-pumping relay in reverse order.
ee)
Check the door and side cover seals to be in place and in good order, replace the seals if
damaged or perished and re-fit all the covers.
ff)
Re-fit the mechanism cover, insert the holding screws and tighten them.
4.2.3.9
Adjustments
Not applicable.
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DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
4.3
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
20 of 26
Modifications
Not applicable.
5
Testing
a)
Test contact resistance across main and transfer contacts: Maximum 60μΩ per phase.
b)
Test minimum release voltage of main and back-up trip coils is 70% of nominal voltage.
c)
Measure trip and close coil current.
d)
Check closing and opening times with a speed recorder:
-
Opening time 40ms ±10ms.
Closing time 140ms-145ms ±10ms.
Make/Trip time 40ms ±10ms.
Make/Break time 30ms ±10ms.
e)
Note spring rewind time of the motor - <10 seconds, 3 crank revolutions when manually
charged.
f)
Note resistivity values of the coils for future references.
g)
Note maximum allowable time discrepancies between phases.
-
Close maximum 5 ms.
Open maximum 5 ms.
h)
Carry out insulation test if leakage to earth is suspected due to damaged bushings,
contaminated oil or excessive moisture found inside breaker pole.
6
Related/Supporting Documents
6.1
Related Documents
a)
Critical task analysis:
1.
2.
3.
Work in Live Chambers and Prohibited areas;
High Voltage Operating; and
Work with/on Extension/Single Ladders.
b) Training module;
c) Manufacturers manual.
6.2
Forms and Records
The attached report shall form the record of work done.
The completed report must be returned to the Work Co-ordinator together with the work order and a copy
to the Technical Services Group.
7
Spares
Refer to 4.2.1.1Spares and Materials
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DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
21 of 26
Annex A-Circuit-breaker report
Circuit-breaker report
SUBSTATION
PANEL / FEEDER
Circuit-breaker
TYPE
MAKE
kV
AMPS
POLE NUMBER
SERIAL NUMBER
R Ph:
W Ph:
B Ph:
kA
Mechanism
DRIVE
TYPE
HEATER
Before:
SUPPLY VOLTAGE: (tick which is applicable)
Contact resistance (micro-ohm)
R Phase
W Phase
SERIAL NUMBER
R Ph:
W Ph:
B Ph:
220V D.C.
220V A.C.
COUNTER
After:
110 V D.C.
Tests
B Phase
R Phase
Contact penetration (mm)
W Phase
B Phase
TEST 1
TEST 2
TEST 3
COILS
Minimum trip release voltage
Main
R Ph:
Back-up
R Ph:
Minimum close release voltage
Coil amperage
Main trip:
Coil resistance
Main trip:
W Ph:
W Ph:
Back-up:
Back-up:
Speed recording test
Trip
Phase
Close
Red A
Red B
White A
White B
Blue A
Blue B
Motor rewind time to recharge spring:
Time discrepancies between phases
Insulation test
R Phase
W Phase
S to E
L to E
S to L
Trip:
B Phase
B Ph:
B Ph:
Close:
Close:
Trip/close
Close/trip
Close:
SF6 gas alarm test
o
Nominal at 20 C
Alarms
Lock-out at
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DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
22 of 26
Annex A
(Concluded)
Good
Replaced
Fixed contacts
Arcing ring
Moving contacts
Transfer contacts
Arc control device
Inspect
Close latch
Trip latch
Needle bearings
Interlocks
Checklist
Good
Oil/SF6/Vacuum
Gauge glasses
Seals
Valves
Door seals
Lubricate
Free
Replaced
Good
Coils
Motors
Pumps
Contactor
Counters
Inspect
Lubricate
Replaced
No leaks
Drives
Damper
Springs
Shafts
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DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
23 of 26
Annex B - Impact assessment
1. Guidelines
o
o
o
o
All comments must be completed.
Motivate why items are N/A (not applicable)
Indicate actions to be taken, persons or organisations responsible for actions and deadline for
action.
Change control committees to discuss the impact assessment, and if necessary give feedback to
the compiler of any omissions or errors.
2. Critical points
2.1 Importance of this document. E.g. is implementation required due to safety deficiencies,
statutory requirements, technology changes, document revisions, improved service quality,
improved service performance, optimized costs.
Comment: Statutory requirements and or document revisions
2.2 If the document to be released impacts on statutory or legal compliance - this need to be very
clearly stated and so highlighted.
Comment: No impact on statutory or legal compliance and mainly document revisions
2.3 Impact on stock holding and depletion of existing stock prior to switch over.
Comment: N/A - No new equipment or item need to be acquired for implementation of this document.
2.4 When will new stock be available?
Comment: N/A –see 10.2.3 above.
2.5 Has the interchange ability of the product or item been verified - i.e. when it fails is a straight
swap possible with a competitor's product?
Comment: N/A – It is a maintenance document and also see 10.2.3 above.
2.6 Identify and provide details of other critical (items required for the successful implementation
of this document) points to be considered in the implementation of this document.
Comment: Consult / Refer to SCSASABA8 for revised earth application when implementing the document.
2.7 Provide details of any comments made by the Regions regarding the implementation of this
document.
Comment: None.
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DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
24 of 26
Annex B
(continued)
3. Implementation timeframe
3.1 Time period for implementation of requirements.
Comment: N/A – No technical changes were made to this document.
3.2 Deadline for changeover to new item and personnel to be informed of DX wide change-over.
Comment: None.
4. Buyers Guide and Power Office
4.1 Does the Buyers Guide or Buyers List need updating?
Comment: NO.
4.2 What Buyer’s Guides or items have been created?
Comment: NONE.
4.3 List all assembly drawing changes that have been revised in conjunction with this document.
Comment: NONE – The configuration hasn’t changed.
4.4 If the implementation of this document requires assessment by CAP, provide details under
10.5
Comment: N/A – The revision requires no new equipment / assessment.
4.5 Which Power Office packages have been created, modified or removed?
Comment: NONE:
5. CAP / LAP Pre-Qualification Process related impacts
5.1 Is an ad-hoc re-evaluation of all currently accepted suppliers required as a result of
implementation of this document?
Comment: NO
5.2 If NO, provide motivation for issuing this specification before Acceptance Cycle Expiry date.
Comment: N/A – The document doesn’t specify but stipulated the maintenance procedures on the existing
equipment.
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DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
25 of 26
Annex B
(continued)
5.3 Are ALL suppliers (currently accepted per LAP), aware of the nature of changes contained in
this document?
Comment: N/A – The specification is supplied to the suppliers not this document.
5.4 Is implementation of the provisions of this document required during the current supplier
qualification period?
Comment: Yes – This is the revision of document that is presently being implemented and requires no
change to the supplier’s qualification period.
5.5 If Yes to 10.4, what date has been set for all currently accepted suppliers to comply fully?
Comment: N/A – see 10.5.4 above.
5.6 If Yes to 10.4, have all currently accepted suppliers been sent a prior formal notification
informing them of Eskom’s expectations, including the implementation date deadline?
Comment: N/A – see 10.5.4 above.
5.7 Can the changes made, potentially impact upon the purchase price of the material/equipment?
Comment: N/A – No new material is required.
5.7.1
Material group(s) affected by specification: (Refer to Pre-Qualification invitation schedule
for list of material groups)
Comment: N/A – No new material is required.
6. Training or communication
6.1 State the level of training or communication required to implement this document. (E.g. none,
communiqués, awareness training, practical / on job, module, etc.)
Comment: Practical / On job and training module.
6.2 State designations of personnel that will require training.
Comment: TSO, PTO & STO.
6.3 Is the training material available? Identify person responsible for the development of training
material.
Comment: Yes – DT- Training is revising earthing related training manual which will address the changes
in this document.
6.4 If applicable, provide details of training that will take place. (E.G. sponsor, costs, trainer,
schedule of training, course material availability, training in erection / use of new equipment,
maintenance training, etc).
Comment: Safety and Maintenance training.
When downloaded from the DT WEB, this document is uncontrolled and the responsibility rests with the user
to ensure it is in line with the authorised version on the WEB.
DOCUMENT CLASSIFICATION: CONTROLLED DISCLOSURE
CIRCUIT-BREAKER: DELLE / ALSTOM
TYPE: HG 710 & HG 720
RATINGS: 33kV; 1250A
MECHANISM: BLR, BLRM & BLRME
Unique Identifier:
34-960
Type:
DMN
Revision:
0
Page:
26 of 26
Annex B
(concluded)
6.5 Was Training & Development Section consulted w.r.t training requirements?
Comment: Yes.
7. Special tools, equipment, software
7.1 What special tools, equipment, software, etc will need to be purchased by the Region to
effectively implement?
Comment: NONE.
7.2 Are there stock numbers available for the new equipment?
Comment: N/A – No new equipment is required.
7.3 What will be the costs of these special tools, equipment, software?
Comment: N/A – No new equipment is required.
8. Finances
8.1 What total costs would the Regions be required to incur in implementing this document?
Identify all cost activities associated with implementation, e.g. labour, training, tooling, stock,
obsolescence
Comment:
No costs other than the training will be incurred by the regions and this will depend on the arrangements
made for training ie Training is held regionally or nationally.
Impact assessment completed by:
Name: David M. Ntombela
Designation: Consultant
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