-
Page 1 of 16
MAINTENANCE STANDARD GUIDELINE ONTARIO OPERATIONS
TITLES:
Electrical Electrical Department Electrical Maintenance Best
Practices
VALE
MGUID-50006
PAGE
Page 1 of 16
DATED
2016-04-26 REV
2
Training Code (If applicable):
N/A
Document Owner: Name: Phil Langlois Position: Lead Electrical
Engineer, Electrical Department
Table of Contents
1.0
PURPOSE.......................................................................................................................................................................
2
2.0 SCOPE
...........................................................................................................................................................................
2
2.1. EXCEPTIONS
................................................................................................................................................................
2
3.0 REFERENCES
..................................................................................................................................................................
2
4.0 CONTEXT
.......................................................................................................................................................................
3
5.0 COMMITMENTS
............................................................................................................................................................
3
6.0 DEFINITIONS
.................................................................................................................................................................
3
7.0 ELECTRICAL MAINTENANCE BEST PRACTICS
..................................................................................................................
4
7.1. DRAWINGS
.....................................................................................................................................................................
4 7.2. BREAKER MAINTENANCE
...................................................................................................................................................
5 7.3. HIGH VOLTAGE SWITCHGEAR RELAY TESTING
........................................................................................................................
7 7.4. NGR TESTING
.................................................................................................................................................................
8 7.5. PERSONAL AND OTHER PROTECTIVE EQUIPMENT
...................................................................................................................
9 7.6. ELECTRICAL ROOM MAINTENANCE
....................................................................................................................................
10 7.7. OVERHEAD LINE MAINTENANCE
........................................................................................................................................
11 7.8. POWER SYSTEM STUDIES
.................................................................................................................................................
12 7.9. HIGH VOLTAGE SWITCH MAINTENANCE (S&C)
....................................................................................................................
13
8.0 APPENDICES
................................................................................................................................................................
15
Appendix A: Revision Notes and Approvals
.......................................................................................................................................
16
-
Maintenance Standard Guideline
Page 2 of 16
Electrical Electrical Department
MGUI-50006 Electrical Maintenance Best Practices Rev 2
1.0 PURPOSE
Electrical maintenance programs vary a great deal from site to
site as electrical maintenance management either does not possess
the necessary expertise or time to research such requirements. This
guideline has been created to provide sites with information on
best practices to consider when setting up an electrical
maintenance program to ensure zero harm in the workplace. Where a
defined best practice is “required to achieve regulatory or
standards compliance”, it has been written in normative (mandatory)
language. It is the site’s responsibility to ensure its processes
in these areas are in compliance with current legislative
requirements and standards as is applicable.
2.0 SCOPE
This guideline may be referenced by all Vale Ontario sites.
2.1. EXCEPTIONS
None
3.0 REFERENCES
The following documents were used in the development of this
document or are related to it. They shall be used in their most
recent revision.
CSA-M421-11 Use of electricity in mines
CSA-Z462-15 Workplace electrical safety
IHSA/EUSA Infrastructure Health and Safety
Association/Electrical Utility Safety Association – rules for
utility work
NFPA-70B Recommended Practice for Electrical Equipment
Maintenance
OSHA Occupational Health and Safety Act
Regulation #854 Mines and Mining Plants
CSA Z463-13, Guideline on Maintenance of Electrical Systems
OESC-12, Ontario Electrical safety Code, Part I
-
Maintenance Standard Guideline
Page 3 of 16
Electrical Electrical Department
MGUI-50006 Electrical Maintenance Best Practices Rev 2
4.0 CONTEXT
Without getting into site-specific electrical maintenance
requirements or specific programs for all equipment, there are
industry accepted “best practices” which should be considered for
all Vale sites. This guideline identifies best practices including
references to federal and provincial - guidelines, standards and
acts where applicable. Personnel safety and equipment reliability
will suffer if these mandatory requirements are not met. Best
practices in this document have been grouped into the following
categories:
1. Drawings 2. Breaker Maintenance 3. High Voltage Switchgear
Relay Testing 4. Neutral Grounding Resistor (NGR) Testing 5.
Personal and Other Protective Equipment 6. Electrical Room
Maintenance 7. Overhead Line Maintenance 8. Power System Studies 9.
High Voltage Switch Maintenance (S&C)
For each category, a table is provided that provides information
in the following format:
1. Background 2. Applicable requirements (federal or provincial
- guidelines, standards, codes or acts) 3. Recommended “best
practices” approach
5.0 COMMITMENTS
This guideline (MGUID-50006) is committed to comply with:
The Vale HomeSafe program; and
The Occupational Health and Safety Act.
6.0 DEFINITIONS
Best Practice: Procedures that are accepted or prescribed as
being correct or most effective.
-
Maintenance Standard Guideline
Page 4 of 16
Electrical Electrical Department
MGUI-50006 Electrical Maintenance Best Practices Rev 2
7.0 ELECTRICAL MAINTENANCE BEST PRACTICS
7.1. DRAWINGS
Background
Updated drawings permit safe isolation and guide
troubleshooters. They assist planners, engineers and consultants
thereby reducing ongoing costs.
Requirements mentioned in the Act, regulations, codes, standards
and guidelines
OSHA, 29(2), “…six months…” Reg#854, 22, “…maintained…legible…”
CSA-M421-11, section 4.2.1, “…annually or after any significant
change…” CSA-Z462-15, section 5.2.2, “…single line…legible…kept
current”, Annex B5, Annex E(3)(i) OESC-12, section#36-006(5),
“…metal enclosed switchgear…legible…single line diagram” CSA
Z463-13, section 4.7.5(b), 5.16.2(b)
Recommended “Best Practice” approach
Each site will appoint a Drawing Coordinator for electrical and
instrumentation mark-ups (single lines, schematics and wiring,
panel schedules, loop diagrams, layouts, etc.).
All drawing revisions are to be channeled through the
Coordinator for updating services provided by the Central
Engineering Department (CED).
The Coordinator will verify the quality of the plant mark-ups
and make sure that references are adequate before sending the
drawings to CED.
When drawings are returned from CED, the Coordinator will
distribute the revisions to the correct crews (if paper copies are
involved, e.g. single lines for posting in electrical rooms).
All returned drawings are checked by the Coordinator for missing
information or for code violations cited by CED and action is taken
or scheduled to obtain resolution.
Each Site Coordinator will track the missing information and
code violation requests to make sure there is resolution on these
matters.
CED will track how many drawings have been sent for revision on
an annual basis, how many drawings are returned and the time taken
to obtain those revisions. These quantities are measurable metrics
which can be audited.
-
Maintenance Standard Guideline
Page 5 of 16
Electrical Electrical Department
MGUI-50006 Electrical Maintenance Best Practices Rev 2
7.2. BREAKER MAINTENANCE
Background
Maintained breakers assure safe operation when called to do so.
During faults, their timely action permits the selected PPE to
adequately protect the worker and limit outages to the faulty or
overloaded areas only.
Requirements mentioned in the Act, regulations, codes, standards
and guidelines
OSHA, 25(2)(h), “…every precaution reasonable…”, 29(1)(a)(ii),
“…facilities…maintained as prescribed…”
CSA-M421-11, section 4.10, “…electrical equip…maintained…safety
not compromised”
CSA-Z462-15, section 5.2.3, section 5.3.5, “…maintained to
function in accordance to their designed operating times”, section
5.6, Annex B12
NFPA-70B-10, section 11.10 for low voltage breakers, section
11.16 for high voltage and chapters 15 & 17
CSA Z463-13, section#8.2.7 & Table M.4.1 “circuit
breakers”
OESC-12, section#2-300, “…operating electrical equipment shall
be kept in a safe and proper working condition”
Recommended “Best Practice” approach
The following services can be supplied by Vale’s Power
Department (Protection and Control) in the Sudbury area if the
breakers are located on surface. For underground breaker testing,
the service must be obtained by non-Vale personnel at the current
staffing levels.
A list will exist which contains all the site’s MCCBs, LVCBs
& HVCBs and their scheduled service intervals. The maintenance
paperwork will be kept in an easily accessible area in the event of
ministry investigations.
Dated stickers will be affixed to the breakers after servicing.
Breakers which exhibit issues during servicing are to be
re-serviced three months after servicing to make sure the issues
have gone away.
When breakers interrupt faults approaching their interrupting
ratings, they shall be inspected before being re-closed. Low
Voltage Power Molded-Case Circuit Breakers (MCCBs-600volt)
MCCBs are to be serviced every three years.
MCCBs which have re-occurring issues are to be removed from
service and replaced by other breakers. The problematic breakers
are to be replaced in kind due to downstream arc flash incident
energy level calculated risks on the posted labels.
All MCCBs having solid state trip units (such as the RMS-310
& Seltronic) are to have their units tested using secondary
injection.
All MCCBs equipped with shunt trips (such as Startco NGR relays)
will be tripped using this feature.
-
Maintenance Standard Guideline
Page 6 of 16
Electrical Electrical Department
MGUI-50006 Electrical Maintenance Best Practices Rev 2
All MCCBs equipped with manual trip buttons will be tripped
using this feature.
All MCCBs will be exercised several times.
All MCCBs shall be maintained free of cracks in their cases and
cracked or broken operating handles.
All MCCBs which are suspect or which exhibit hotspots during
NDEs will be inspected internally as well.
In order to keep the Power Department (Sudbury area only) test
equipment inventory to a minimum, standardize on the following
solid state trip units for 600volt MCCBs: Cutler-Hammer Digitrip
RMS310 or Seltronic units.
Low Voltage Power Circuit Breakers (LVCBs)
LVCBs are to be serviced every three years as a minimum
(cleaned, exercised, racked-in/out, contact resistance tested,
meggered, etc).
LVCBs which have re-occurring issues are to be removed from
service and replaced by other breakers. The problematic breakers
are to be sent for rebuild and not refurbishment. If sufficient
funds permit, consider replacing the defective breaker with another
type of breaker in order to minimize the different styles of
breakers at the site. When selecting other types, select a type
which allows the rack in/out process to be done using a racking
screw type thereby allowing more distance between the user and the
possible arc flash (permits adding an extension).
All LVCBs having solid state trip units (such as the Amptector,
I-Tektor, Suretrip and Westrip) are to have their first trip
performed electrically using a 9volt battery (terminals OP &
ON) or using an alternative method thus proving that the breaker
would have tripped before being serviced. Some older versions
having high impedance trip actuators will not allow this functional
test before servicing.
All LVCBs having solid state trip units are to have their units
tested using secondary injection and the settings compared to the
posted single line drawings.
In order to keep the Power Department (Sudbury area only) test
equipment inventory to a minimum, standardize on the following
solid state trip units for 600volt LVCBs: older units are the
Westinghouse Amptector and I-Tektor while the newer units are the
Westrip and the Cutler-Hammer Digitrip units. ABB-SACE breakers
found on ABB-VFDs come with PRC111 trip units. All new trip units
should be purchased with the arc flash maintenance mode feature on
them and with LSIG functionality.
All LVCBs having dashpot protection will be replaced with
breakers having solid state trip units since dashpots can only be
tested using primary injection which apart from having serious
safety implications, is too costly and cumbersome a program to
implement. These old dashpots are likely missing oil which will
cause nuisance trips or gummed-up causing them to trip slower or
not at all. Also, the lack of testing is a liability when personnel
are relying on arc flash labels for the proper PPE protection.
Local on-hand LVCB spares will be available
-
Maintenance Standard Guideline
Page 7 of 16
Electrical Electrical Department
MGUI-50006 Electrical Maintenance Best Practices Rev 2
Medium and High Voltage Power Circuit Breakers (HVCBs)
HVCBs are to be serviced every three years at a minimum for
spring charge breakers and every 5 years for magnetically operated
breakers (cleaned, exercised, contact resistance testing, hi-pot of
vacuum bottles, cell interlock checks, etc.).
HVCBs will be first tripped using the relay protection relays
thus proving the protection circuits and the functionality. This
function is performed by the Power Department Technician in the
Sudbury area.
HVCBs having an air breaking medium are to be converted to
vacuum technology during rebuilds. For large and heavy breakers
such as the GE Magna-blast breakers or the DHP breakers, converting
them to vacuum will eliminate the asbestos shields and the
ergonomic liability. When comparing rebuild options, try obtaining
3 cycle operating times to lower incident energy levels as
well.
New HVCBs purchases will be standardized across the site and
possibly the division to minimize training requirements, assurance
of spares and local expertise.
7.3. HIGH VOLTAGE SWITCHGEAR RELAY TESTING
Background
Maintained relays assure safe operation when called to do so and
at expected settings. During upset conditions, their predictable
action permits the selected PPE to adequately protect the worker
and for proper coordination and isolation of faulted circuits.
Requirements mentioned in the Act, regulations, codes, standards
and guidelines
OSHA, 25(2)(h), “…every precaution reasonable…”, 29(1)(a)(ii),
“…facilities…maintained as prescribed…”
CSA-M421-11, section 4.5.5, “…before initial use and after every
three years of use…”
CSA-Z462-15, section 5.2.3 & 5.2.4, “…industry standards”,
Annex B.2
NFPA-70B-10, section 11.12, “…every 2 years…” in 11.12.1.1.2
CSA Z463-13, section#8.2.9 and Table M.6
OESC-12, section#2-300, “…operating electrical equipment shall
be kept in a safe and proper working condition”
Recommended “best practices” approach
All high voltage switchgear relays (electromechanical &
digital) will be tested every three years to ensure their
functionality and verify that settings have not been altered.
Relay settings will not be altered without the necessary
engineering approvals, updating the power system studies and
posting new arc flash labels.
Dated stickers will be affixed to the relay or relay cases
thereby allowing the sites to know if their relays are due for
testing during electrical room audits.
This service can be supplied by Vale’s Power Department
(Protection and Control) in the Sudbury area if the relays are
located on surface. For underground relay testing, the service must
be obtained by non-Vale personnel at the current staffing
levels.
-
Maintenance Standard Guideline
Page 8 of 16
Electrical Electrical Department
MGUI-50006 Electrical Maintenance Best Practices Rev 2
Where competing documentation exists, the area authority will
either coordinate the updating of drawings and documents or clearly
indicate “obsolete” on the old documents and drawings.
A standard job template is available for this task - SAP Task
List Group 34883 1Y Testing,Kiruna Trly SubStn Relay, MEL (Contact:
Plant Planner for more details)
7.4. NGR TESTING
Background
Testing the power connections on NGRs which do not have
monitoring resistors assures the site that the ground fault
protection is still available.
Requirements mentioned in the Act, regulations, codes, standards
and guidelines
OSHA, 25(2)(h), “…every precaution reasonable…”, 29(1)(a)(ii),
“…facilities…maintained as prescribed…”
CSA-M421-11, section 4.5.6 & 4.6.2(b), general information
only
CSA-Z462-15, section 5.2.3 “..in accordance with manufacturer’s
instructions…”
OESC-12, section#2-300, “…operating electrical equipment shall
be kept in a safe and proper working condition” and section 10-1100
to 10-1108 for general information
Recommended “best practices” approach
Each site will have a list containing all their NGRs.
NGRs having a resistor monitoring the primary connection will
not require any yearly servicing.
NGRs not having a sensing resistor require yearly assessments of
the power connections. This may or may not require an outage.
Keeping in mind to standardize with Startco’s SE-330, SE-325 and
SE-105, the sites will consider adding the monitors to all NGRs
This service can be supplied by Vale’s Power Department
(Protection and Control) in the Sudbury area if the NGRs are
located on surface. For underground NGR testing, the service must
be obtained by non-Vale personnel at the current staffing
levels.
-
Maintenance Standard Guideline
Page 9 of 16
Electrical Electrical Department
MGUI-50006 Electrical Maintenance Best Practices Rev 2
7.5. PERSONAL AND OTHER PROTECTIVE EQUIPMENT
Background
It is a legal requirement to provide and maintain safety gear.
Maintained gear will offer the intended protection to the
worker.
Requirements mentioned in the Act, regulations, codes, standards
and guidelines
OSHA, 25(1), “provide…maintain…safety equipment”, 25(2)(h),
“…every precaution reasonable…”
CSA-Z462-15, section 4.3.7, personal and other protective
equipment
IHSA/EUSA-09, section 134 & Table 3, live line tool
maintenance
Recommended “best practices” approach
All plants will follow SPI-SAF-462 when purchasing arc flash PPE
for their electrical crews.
Testing of Rubber Insulated Gloves (Refer to maintenance
standard procedure: MPROC-50002). The Power Department and those
utilizing gloves for “primary protection” will test low and high
voltage gloves every 90 days and have expiry dates on their gloves
to comply with EUSA-09 Section #134 and Table 3. All other sites
and departments are not to request expiry dates on their gloves and
are to test them every 6 months for high voltage and every year for
low voltage.
Testing of Hot Sticks (Refer to maintenance standard procedure:
MPROC-50005 – Hot Stick Procedure). Although it is permitted to
test at an interval of every 3 years, hot stick testing will occur
yearly for the Power Department and every three years for all other
departments. All hot sticks will have expiry dates on them. Some
departments may opt to replace them instead of testing them to be
compliant.
Testing of high voltage detectors (Refer to maintenance standard
procedure: MPROC-50009 – Modiewark Voltage Detector). It is
permitted to test at an interval of every 3 years, but yearly
testing will occur for the Power Department. All detectors will
have battery replacement & test dates on them.
-
Maintenance Standard Guideline
Page 10 of 16
Electrical Electrical Department
MGUI-50006 Electrical Maintenance Best Practices Rev 2
7.6. ELECTRICAL ROOM MAINTENANCE
Background
Maintaining electrical rooms will not only benefit the
equipment, but will promote positive behavioral changes. Achieving
zero harm is not possible without it.
Requirements mentioned in the Act, regulations, codes, standards
and guidelines
OSHA, 29(1)(a)(ii), “…facilities…maintained as prescribed…”
CSA-M421-11, section 4.10, “…electrical equip…maintained…safety
not compromised”
CSA-Z462-15, all sections
NFPA-70B-10, all sections
CSA Z463-13, all sections
OESC-12, section#2-300, “…operating electrical equipment shall
be kept in a safe and proper working condition”
Recommended “best practices” approach
Each site will have a list containing all their substations and
electrical rooms.
Yearly, perform NDE on every substation and electrical room
focusing mostly on the 600volt distribution racks. Re-scanning the
“hotspots” after repairs are made is implied. Document all actions
taken.
Depending on the site conditions, electrical rooms will be
cleaned at appropriate intervals to keep them locked (controlled
access), cleaned and dry.
Check condition of the signage and the labels.
Check that the posted single lines are the latest revision in
j-DMS and that they are legible.
Remove all flammable/combustible materials.
Make sure all switchgear doors are closed and fastened.
Verify that cable entries and other openings have been sealed
with fire retardant materials.
If any switchgear openings have been ignored, have knock-outs or
other suitable barriers installed.
Replenish the locks and tags.
Verify that all relay stickers and breaker stickers are no more
than three years old.
Verify that the arc flash labels are no more than five years
old.
Depending on the seasons, either turn ON/OFF the heaters or turn
ON/OFF the exhaust fans.
Check for water ingress and correct immediately.
Older out of service or spare switchgear that is still connected
will be tagged for removal at the next outage to prevent using them
out of convenience instead of adding new equipment. This will
eliminate asbestos containing equipment, eliminate starters having
two overloads and eliminate equipment rated at only 22 kA. ( a new
procedure is being written to clarify this topic)
-
Maintenance Standard Guideline
Page 11 of 16
Electrical Electrical Department
MGUI-50006 Electrical Maintenance Best Practices Rev 2
Vale plant sites have SAP – Task Lists (standard jobs) specific
to their area for conducting inspections of electrical rooms and
power centers. NOTE: Refer to your plant’s Planner to ensure you
are accessing or using the most recent SAP Task List for this
inspection work. The following are samples of task lists available
at the date of this guideline. Contact your Plant Planner for more
details.
o Coleman Mine: SAP Task List 348861 – Inspect Electrical
Switchroom, MEL o Garson Mine: SAP Task List 31631 3M Inspect,
Switchroom, MEL o Creighton Mine: SAP Task List 30245 6M Inspect,
Switchroom, MEL o Totten Mine: SAP Task List 32461 1M Inspect,
Switchroom, MEL o Copper Cliff Mine: SAP Task List 31134 6M
Inspect, Switchroom, MEL o Clarabelle Mill: SAP Task List 37014 3M
Inspect/Clean,SwitchRoom,Area30,Mel o SAP – Task List 34887 1Y
Testing Load Centre & Area Relay
7.7. OVERHEAD LINE MAINTENANCE
Background
Overhead lines are often assumed to be the property of the Power
Department’s linegang which is not the case. All overhead lines
rated below 69/44 kV are owned and maintained by the plant
site.
Requirements mentioned in the Act, regulations, codes, standards
and guidelines
OSHA, 29(1)(a)(ii), “…facilities…maintained as prescribed…”
CSA-M421-11, section 4.10, “…electrical equip…maintained…safety
not compromised”
CSA-Z462-15, too many sections to list
NFPA-70B-10, too many sections to list
CSA Z463-13, section#8.2.24 and Table M.1
OESC-12, section#2-300, “…operating electrical equipment shall
be kept in a safe and proper working condition”
Recommended “best practices” approach
Each plant will have a schedule set-up for overhead line
maintenance for all lines which do not belong to the utility or to
the Vale Power Department. The following seasonal tasks will be
performed by trained and experienced personnel: Spring chopper/foot
patrol:
The helicopter must fly at a speed which is slow enough for
visual inspection
The helicopter must fly at a safe distance but close enough for
visual inspection
Check for broken or burnt insulators
Check for defective cross arms
Check for brush & tree egress
Check for leaning poles & structures
Check that safety signs are still affixed to the poles (ESA
requirement)
Check that all guy wires are still tight
-
Maintenance Standard Guideline
Page 12 of 16
Electrical Electrical Department
MGUI-50006 Electrical Maintenance Best Practices Rev 2
Fall foot patrol:
Check all items aforementioned in the spring patrol
Check that no garbage has been left around the poles
Ground rod visual inspection
Check for rusting & rotting on the guy wire anchors
Sound the poles with a hammer at its base and as high as
possible while standing
Check soil condition surrounding the pole
Check pole crack depths
Check pole crack alignments from one side to the next
7.8. POWER SYSTEM STUDIES
Background
Power system studies contain short circuit calculations, device
evaluation, coordination and arc flash hazard risk calculations for
all electrical distribution components at each site and such are
the plant’s go-to location for all major issues and upgrade
inquiries.
Requirements mentioned in the Act, regulations, codes, standards
and guidelines
CSA-Z462-15, section 4.3.5.1(b), “arc flash analysis…updated
when a major modification or renovation takes place. It shall be
reviewed periodically, not exceeding 5 years…”
Recommended “best practices” approach
All sites will have their electrical distributions modeled
within a power system study while performing arc flash modeling.
This study will follow the maintenance standard procedure:
MPROC-50003 – Power System Study Procedure.
In Appendix E of the study, confirm all “assumptions” before the
next revision.
In Appendix E of the study, correct or implement solutions to
eliminate equipment rating issues.
In Appendix E of the study, correct or implement solutions to
eliminate relay, fuse and/or breaker coordination issues
In Appendix E of the study, correct or implement solutions to
mitigate arc flash hazards permitting personnel to wear less
PPE.
-
Maintenance Standard Guideline
Page 13 of 16
Electrical Electrical Department
MGUI-50006 Electrical Maintenance Best Practices Rev 2
7.9. HIGH VOLTAGE SWITCH MAINTENANCE (S&C)
Background
High voltage switches (mostly S&C brand for Vale) are
assumed to be bullet proof. Although a good product, they still
require exercising and servicing depending on their
application.
Requirements mentioned in the Act, regulations, codes, standards
and guidelines
OSHA, 29(1)(a)(ii), “…facilities…maintained as prescribed…”
CSA-M421-11, section 4.10, “…electrical equip…maintained…safety
not compromised”
CSA-Z462-15, too many sections to list
NFPA-70B-10, too many sections to list
CSA Z463-13, too many sections to list
OESC-12, section#2-300, “…operating electrical equipment shall
be kept in a safe and proper working condition” General Information
from various S&C Installation & Maintenance Manuals.
S&C is a quality robust product requiring very little
maintenance over the years when
properly installed. Mechanical maintenance is generally not
required. The only
maintenance recommended consists of periodic cleaning and
inspection of
interrupter-switch, fuse and bus supports on intervals based on
environmental
conditions. The integrity of the enclosure finish should be
checked and any scratches
or chips should be touched-up with the appropriate touch-up
finish. Also, occasional
exercising of interrupter switches and switch operators as well
as inspection of keyed
interlocks is recommended.
Metal enclosed switchgear should be inspected 6 months to a year
after installation
then every 5 years thereafter depending on the each user’s own
experience as well
as environmental conditions. The Mini-Rupter and Alduti-Rupter
switches should be
cleaned and re-lubricated every 10 years.
It is not unusual for regular operations of interrupter switches
to take place once every
5 years. Fuse replacement is very infrequent since fuse
operations (blowing) occur on
an average of once every 20 years.
Recommended “best practices” approach
For most feeder switches (switches which see less than one or
two operations per month
on average over the years), operate them when servicing the low
and/or high voltage
breakers approximately every three to five years. When operating
them, open the door
and perform a visual to determine if cleaning and re-lubrication
should be scheduled. Test
the Kirk-key as well.
-
Maintenance Standard Guideline
Page 14 of 16
Electrical Electrical Department
MGUI-50006 Electrical Maintenance Best Practices Rev 2
For feeder switches having higher than normal usage such as
skip/cage hoists and trolley
substations, annual inspections are required to make sure the
switches are closing
properly and for re-lubricating them. The site should calculate
its weekly or yearly
expected operations and plan to replace the switches at roughly
500 operations. Leeway
is available here and the calculated incident energy levels from
the models and the safety
& production implications due to downtime to the site should
be factors to consider as
well.
-
Maintenance Standard Guideline
Page 15 of 16
Electrical Electrical Department
MGUI-50006 Electrical Maintenance Best Practices Rev 2
8.0 APPENDICES
APPENDIX A: Revision Notes and Approvals
-
Maintenance Standard Guideline
Page 16 of 16
Electrical Electrical Department
MGUI-50006 Electrical Maintenance Best Practices Rev 2
Appendix A: Revision Notes and Approvals
The Revision Notes and Approvals table only displays the latest
revision number and a list of the last revisions made to the
document. For details on previous revisions contact the document
owner.
Rev Revision Notes
Last Revised by: Phil Langlois, Electrical Lead, Electrical
Department, Ontario Operations
2
SPI-ENG-006 revised as follows:
updated SAP Task List references where applicable
document reformatted to maintenance standard guideline
format
added clarification on purpose of the guideline and references
to best practices that have legislative or standard adherence
requirements
Added references CSA Z462 and updated OESC to recent revised
editions.
1
SPI-ENG-006 released July 9, 2012