20170303IPC to Tidwell Attachment 18.6.pdf

Transmission Maintenance
and Inspection Plan (TMIP)

January 2017
© 2017 Idaho Power
Idaho Power Company Transmission Maintenance and Inspection Plan
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TABLE OF CONTENTS
Table of Contents ............................................................................................................................. i
Introduction ......................................................................................................................................1
Western Electricity Coordinating Council (WECC)-Defined Facilities ..........................................1
Path 14: Idaho to Northwest ......................................................................................................1
Location ...............................................................................................................................1
Lines ..................................................................................................................................1
Path 16: Idaho–Sierra .................................................................................................................2
Location ...............................................................................................................................2
Lines ..................................................................................................................................2
Path 17: Borah West ..................................................................................................................2
Location ...............................................................................................................................2
Lines ..................................................................................................................................2
Path 18: Montana–Idaho ............................................................................................................3
Location ...............................................................................................................................3
Lines ..................................................................................................................................3
Path 20: Path C...........................................................................................................................3
Location ...............................................................................................................................3
Lines ..................................................................................................................................4
Path 55: Brownlee East ..............................................................................................................4
Location ...............................................................................................................................4
Lines ..................................................................................................................................4
T&D Maintenance Department........................................................................................................5
Maintenance Activities ..............................................................................................................5
Routine Line Patrols/Inspections .........................................................................................5
Comprehensive Maintenance Plan .......................................................................................7
Pole Inspection and Ground-Line Treatment .................................................................7
Detailed Visual Inspection .............................................................................................8
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Contamination Control (Insulator Washing) .............................................................................8
Measures and Tracking ..............................................................................................................9
Review/Revision History ...............................................................................................................10

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INTRODUCTION
The Transmission Maintenance and Inspection Plan (TMIP) will be reviewed and approved
annually. This approval is required by January 15 of each year.
WESTERN ELECTRICITY COORDINATING COUNCIL
(WECC)-DEFINED FACILITIES
Path 14: Idaho to Northwest
Location
Southwest Idaho, eastern Oregon/Washington, and northern Idaho
Lines
 Midpoint–Hemingway–Summer Lake 500 kilovolt (kV) (two line sections make up Idaho
Power Company [IPC]-owned part of the path) (path SOL is lowered for outage of
this section)
 Line #606, Midpoint Bus tie 345 kV (IPC owned and maintained) (path SOL is lowered
for outage of this section)
 Line #856, Hemingway-Summer Lake 500 kV, (shared ownership IPC & Pacificorp, IPC
maintained Hemingway to Oregon state line) (SMLK–HMWY is part of path definition in
WECC path catalog)
 Line #857, Midpoint-Hemingway 500 kV, (shared ownership IPC & Pacificorp, IPC
maintained) (path SOL is lowered for outage of MPSN–HMWY)
 Oxbow–Lolo 230 kV (two line sections make up IPC-owned part of the path):
 Line #907, Oxbow–Pallette Jct. 230 kV (IPC owned and maintained) (part of path
definition of WECC path catalog)
 Line #908, Pallette Jct.–Imnaha 230 kV (IPC owned and maintained) (part of path
definition of WECC path catalog)
 Hells Canyon–Hurricane 230 kV (two line sections make up IPC-owned part of the path):
 Line #910, Hells Canyon–Pallette Jct. 230 kV; dbl. circuit includes HCPR–BLPR and
HCPR–WALA (IPC owned and maintained) (HCPR–WALA is part of path definition of
WECC path catalog; HCPR–BLPR path SOL is lowered for outage of this section)
 Line #913, Pallette Jct.–Hurricane 230 kV (IPC owned and maintained) (part of path
definition of WECC path catalog)
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 Line #903, Brownlee–Quartz Jct. 230 kV (IPC owned and maintained) (path SOL is lowered
for outage of this section)
 Line #701, Quartz Jct.–North Powder–LaGrande 230 kV (IPC owned and maintained)
(path SOL is lowered for outage of this section)
 Line 435 Quartz–West John Day 138 kV (IPC owned and maintained) (path SOL is lowered
for outage of this section)
 Line #390, Hines–Harney 115 kV Tie (IPC owned and maintained) (part of path definition of
WECC path catalog)
 Brownlee–Hells Canyon 230 kV (three line sections make up this part of the path):
 Line #905, Brownlee–Oxbow 230kV (IPC owned and maintained) (path SOL is lowered
for outage of this section)
 Line #907 (already listed above)
 Line #910 (already listed above)
Path 16: Idaho–Sierra
Location
Border between southern Idaho and northern Nevada
Lines
 Midpoint (IPC)–Humboldt (NV Energy) 345–kV line. (The point of interconnection between
IPC and NV Energy is the Idaho–Nevada state line.)
 Line #803 Midpoint–Stateline 345 kV (IPC owned and maintained) (part of path
definition of WECC path catalog)
Path 17: Borah West
Location
Southeast Idaho
Lines
 Kinport–Midpoint 345 kV (two line sections make up this part of the path):
 Line #804, Kinport–Borah 345 kV (IPC owned and maintained) (part of path definition
of WECC path catalog)
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 Line #850, Borah–Midpoint 345 kV (IPC owned and maintained) (part of path definition
of WECC path catalog)
 Line #950, Borah–Adelaide–Midpoint #1 345 kV (IPC owned and maintained) (part of path
definition of WECC path catalog)
 Line #951, Borah–Adelaide and Adelaide–Midpoint #2 345 kV (IPC owned and maintained)
(Borah–Adelaide is part of path definition of WECC path catalog; Adelaide–Midpoint path
SOL is lowered for outage of this section)
 Line 952 Adelaide Tap–Adelaide 345 kV (IPC owned and maintained) (part of path
definition of WECC path catalog)
 Line #702, Midpoint–Hunt 230 kV (IPC owned and maintained) (path SOL is lowered for
outage of this section)
 Line #722, Borah–Hunt 230 kV (IPC owned and maintained) (part of path definition of
WECC path catalog)
 American Falls–Raft River–Minidoka 138 kV (two line sections make up this part of
the path):
 Line #426, American Falls–Raft River–Minidoka 138 kV (IPC owned and maintained)
(part of path definition of WECC path catalog)
 Line #403, Minidoka–Minidoka Jct. 138 kV (IPC owned and maintained) (part of path
definition of WECC path catalog)
Path 18: Montana–Idaho
Location
Eastern Idaho and western Montana
Lines
 Line #703, Brady–Antelope 230 kV (IPC owned and maintained) (path SOL is lowered for
outage of this section)
Path 20: Path C
Location
Northern Utah/southern Idaho
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Lines
 Line #704, Treasureton–Sunbeam–Brady 230 kV (IPC owns and maintains the first two
spans out of Brady; PacifiCorp owns and maintains the rest of the line to Treasureton)
(part of path definition of WECC path catalog)
Path 55: Brownlee East
Location
Southwest Idaho
Lines
 Line #904, Brownlee–Boise Bench #1 230 kV (IPC owned and maintained) (part of path
definition of WECC path catalog)
 Line #904, Brownlee–Boise Bench #2 230 kV (IPC owned and maintained) (part of path
definition of WECC path catalog)
 Line #911, Brownlee–Boise Bench #3 230 kV (IPC owned and maintained) (part of path
definition of WECC path catalog)
 Line #911, Brownlee–Horse Flat and Horse Flat–Boise Bench #4 230 kV (IPC owned
and maintained) (Horse Flat–Boise Bench path SOL is lowered for outage of this section;
Brownlee–Horse Flat is part of path definition of WECC path catalog)
 Line #701, Quartz–Quartz Jct. 230 kV (IPC owned and maintained) (path SOL is lowered for
outage of this section)
 Line #441, Oxbow–Starkey 138 kV (IPC owned and maintained) (part of path definition of
WECC path catalog)
 Line #412, Ontario–Emmett–Gary–Boise Bench 138 kV (IPC owned and maintained)
(path SOL is lowered for outage of this section)
 Line #423, Ontario–Weiser– Huntington Wind Park–Nelson Tap–Quartz 138 kV (IPC owned
and maintained) (part of path definition of WECC path catalog)
 Line #707, Brownlee–Ontario 230 kV (IPC owned and maintained) (part of path definition of
WECC path catalog)
 Line #715, Ontario–Langley Gulch–Caldwell 230 kV (IPC owned and maintained)
(path SOL is lowered for outage of this section)
 Line #728, Langley Gulch–Willis Tap 230kV operating at 138 kV (IPC owned and
maintained) (path SOL is lowered for outage of this section)
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 Line #474, Caldwell–Willis Tap 138 kV (IPC owned and maintained) (path SOL is lowered
for outage of this section)
T&D MAINTENANCE DEPARTMENT
The Transmission and Distribution (T&D) Maintenance department is responsible for
prioritizing and scheduling all maintenance activities on the transmission system. They are also
responsible for maintaining records of maintenance activities. They provide for routine and
emergency transmission line repairs and establish assessment and inspection intervals. The T&D
Maintenance department monitors transmission line performance and reliability issues.
Maintenance Activities
Two types of line patrols/inspections are conducted on the transmission lines covered by
this plan:
 Routine line patrols/inspections
 Comprehensive Maintenance Plan detailed assessment
Routine Line Patrols/Inspections
Regular and thorough line patrols/inspections are done at least once a year on all major WECC
transfer paths in the bulk electric system (BES) to maintain a high standard of reliability.
These major WECC transfer paths are identified in the WECC Defined Facilities section of this
document. These patrols/inspections are done by ground or air to obtain information on the
condition of transmission facilities and to ensure the integrity of the transmission line system.
The information collected from these patrols/inspections is used for planning and scheduling
maintenance work so defects can be repaired. The air patrols/inspections are used to identify
obvious line-threatening defects and defects that cannot be seen from the ground.
Ground patrol/inspections are made using four-wheel-drive vehicles, all-terrain vehicles (ATV),
utility terrain vehicles (UTV), or on foot. These ground and air line patrols/inspections are done
by four, full-time transmission line patrolmen located in Payette, Boise, Twin Falls,
and Pocatello. The air patrol/inspection on these lines will normally be done by the line
patrolman in addition to an aerial vegetation patrol done by the utility arborist as outlined in the
Transmission Vegetation Management Program (TVMP).
A completed transmission line patrol and maintenance entry in Transmission Reporting and
Asset Management (TRAM) software shall be submitted to the T&D Maintenance department
for all routine line patrols/inspections and shall include the following:
 The person responsible for performing the patrol/inspection
 The dates the patrol/inspection was performed
 The transmission line on which the patrol/inspection was performed
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 A description of the type of inspection that was performed (ground vs. air,
emergency vs. routine)
 A list of defects with priorities assigned to each defect
If scheduling circumstances allow, these routine patrols/inspections should be scheduled prior to
heavy electrical load periods so defects can be repaired when outages are available. Lines located
in seasonally inaccessible areas, such as in high mountains or agriculture lands, should be
patrolled and inspected before the lines become inaccessible each year.
All defects from the routine patrols/inspections are to be reported and prioritized as priority 1,
priority 2, or priority 3 based on the criteria listed below. In TRAM software, for structures not
reported as priority 1, 2, or 3, each individual structure will be listed with no entry in the
defects cell.
 Priority 1: Defects that require attention as soon as possible. These defects clearly pose a
threat to the continued operation of the line or to life and safety. All priority 1 defects or
conditions are to be reported and repaired as soon as possible or evaluated as soon
as possible.
 Priority 2: Defects that need correction but are not an immediate threat. Priority 2
defects can be scheduled during crews’ normal work schedules. Dates are noted if the
defects need corrected within a specified time. Priority 2 defects are to be corrected,
based on an individual evaluation, as soon as deemed necessary or within 24 months after
being identified. Priority 2 defects not corrected within 24 months will be reviewed by
the T&D Maintenance leader.
 Priority 3: Defects that may need correction or do not pose a threat to the system but
should be monitored. These defects are normally evaluated on a case-by-case basis by the
T&D Maintenance department to determine the level of threat they pose to the operation
of the line. Repairs are to be made based on the T&D Maintenance
department evaluation.
All defects identified shall be reported to T&D Maintenance Department using TRAM software
to be evaluated for accuracy and consistency. Either a construction work order or a transmission
work sheet (Appendix A) will be created to initiate repairs of identified defects. The construction
work order or transmission worksheet shall be forwarded to the project schedulers in the Project
Management department and the Regional Coordinator of T&D Construction for construction
scheduling and crew assignment.
Completed defect maintenance correction work orders or work sheets shall include no less than
the following:
 The person responsible for performing the maintenance
 The dates the maintenance was performed
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 The transmission line on which the maintenance was performed
 A description of the type of maintenance that was performed
Defects that are not corrected within the respective time frames based on defect priority will be
documented in TRAM and reviewed by the T&D Maintenance leader. This documentation will
include the following:
 The reason for not completing the work
 The proposed schedule, if applicable, to complete the work
High Priority Trees
High priority trees, as defined by the TVMP, represent any vegetation condition that is likely to
cause a line outage in the next few days or weeks. Upon identification of high-priority threat
conditions, the patrolman will either remove or trim the vegetation immediately, or contact the
utility arborist, who will evaluate the vegetation and arrange for removal or trimming as soon as
possible. All high-priority threat conditions identified by the transmission patrolman will be
documented in TRAM. High priority trees identified by the utility arborist will be documented
on a Transmission Line Clearing Contact sheet.
Any vegetation-related condition that is likely to cause a fault at any moment is also considered a
high-priority threat and must be reported to System Dispatch in Boise without any intentional
time delay. The notification of the threat should be communicated in terms of minutes or hours
by phone or radio.
Annual training will be provided for the transmission patrolmen by the utility arborist on how to
identify high-priority threat vegetation conditions. This training will cover how to differentiate
between high-priority threat conditions that present a risk of causing a fault within hours and
conditions that present a risk of causing a fault within days or weeks.
Comprehensive Maintenance Plan
In addition to the routine yearly patrols/inspections and associated maintenance, this plan
provides for a detailed assessment of IPC transmission lines. This plan will be conducted on all
system major WECC transfer paths in the BES as needed and as listed in the Transmission
Comprehensive Maintenance Schedule. For lines comprised of wood poles, the initial step of the
plan includes the pole inspection and ground-line treatment of all wood poles in the line. If
needed, the second step is a comprehensive, detailed visual inspection of all components of the
transmission line. For lines comprised of steel structures, the detailed visual inspection will be
the first step in the process.
Pole Inspection and Ground-Line Treatment
All wood poles are visually inspected for defects and sounded and bored to detect decay in the
poles. All poles inspected fall into the following five categories:
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1. Reported: Any pole inspected and found to be installed within 10 years of the
inspection date.
2. Treated: Any pole inspected and found to be installed 10 years or more prior to the
inspection date and that, upon further inspection, is found in sound enough condition to
warrant treatment.
3. Rejected: Any pole found to have less than 4" of shell at 48" above the ground line
and/or less than 2" of shell at 15" above the ground line, and/or less than 2” of shell at the
ground line, or is deteriorated below the required strength.
4. Visually Rejected: Any pole that has been burnt, split, broken, or damaged or decayed
above the ground line to such an extent as to warrant rejection.
5. Sounded, Bored, and Treated: Any pole set in concrete, asphalt, or solid rock 10 years
or more prior to the inspection date. These poles shall be internally treated,
which involves fumigating the good wood and flooding the voids with fumigant.
Rejected poles fall into three categories: reinforceable with steel, non-reinforceable, and priority
reject. All non-reinforceable poles will be replaced as part of the general maintenance work
order. All reinforceable poles will be reinforced, generally, during the year following the
groundline inspection. Priority reject poles will be replaced based on engineering analysis.
Detailed Visual Inspection
This is a detailed, comprehensive inspection of all components of the transmission line.
This involves a complete inspection of the poles (above ground), shield wire, spacers, conductor,
insulator assemblies (suspension and dead-end), structures, footings, right-of-way (ROW),
conductor hardware, structure hardware, and phase clearances. These visual inspections are done
for both wood and steel lines and can be performed by either ground or air. The detailed visual
inspection may be done by IPC transmission line patrolmen or by outside contractors as
determined by the T&D Maintenance department. The appropriate inspection method shall also
be determined by the T&D Maintenance department. Thermal or corona inspection may also be
included with the visual inspection if deemed necessary.
The inspectors will provide a record of the line inspected, referencing anomalies by the type of
equipment and by structure number and may photograph abnormal situations and defects.
The data collected from the wood pole inspection report and visual inspection report are
compiled, evaluated, and defects are prioritized according to the routine prioritization criteria.
This data is used to make a general maintenance work order or worksheet for the line to correct
all defects deemed necessary by the T&D Maintenance department. These detailed inspections
are scheduled as needed.
Contamination Control (Insulator Washing)
Insulator washings are not performed as a regular maintenance activity at IPC because the
atmosphere is generally quite clean and contaminates do not generally build up to levels that
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affect operation. There are a few isolated locations where contaminates do build up on insulators,
but none of these are currently on the major WECC transfer paths in the BES. The lines that
do have isolated contamination areas are checked frequently and washed if necessary.
Insulator washings will only be performed in specific areas if contamination is identified as a
problem on our annual patrols.
Measures and Tracking
Each quarter, a meeting is held and documented with the T&D Lines Maintenance
coordinator/designer personnel, the utility arborist, T&D Lines Maintenance engineer, and T&D
Lines Maintenance leader to review and update TRAM and the Transmission Comprehensive
Maintenance Schedule.
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REVIEW/REVISION HISTORY
This document has been approved and revised according to the revision history recorded below.
Review
Date Revisions
03/23/12 NERC compliance process document was adopted.
01/11/13 Changed “System Critical Transmission Lines” to “Major WECC Transfer Paths in Bulk Electric System.”
01/14/13 Under Maintenance Activities, Routine Line Patrols/Inspections for aerial patrols, changed “in conjunction
with” to “in addition to” when referring to vegetation patrols and line patrols. Under Maintenance Activities,
after Priority Description, added “and Transmission Reporting and Asset Management (TRAM).”
04/17/13 Updated WECC defined path lines (for Line 701, added North Powder to name string; added Line 403
Minidoka–Minidoka Jct. 138 kV to Path 17; for Line 601, changed name string to Goshen–Jefferson––
Big Grassy–Stateline; removed Antelope–Anaconda 230 kV)
08/09/13 Updated copyright date from 2012 to 2013.
12/27/13 Removed the word “see” from Transmission Comprehensive Maintenance Plan (see Transmission
Maintenance Schedule) under Maintenance Activities.
01/07/14 Document was updated.
01/13/14 Updated to 2014, added American Falls-Wheelon 138kV (PacifiCorp owned and maintained) to Path C list
of WECC defined facilities. Added “When reported in Transmission Reporting and Asset Management
(TRAM) software, for structures not reported as priority 1, 2, or 3 each individual structure will be listed
with no entry listed in the defects cell” to paragraph describing reporting methods under Routine Line
Patrols/Inspections. Added the word ‘software’ when describing TRAM. Changed requirement for
“Rejected” under Pole Inspection and Groundline Treatment from 1 inch to 2”.
03/11/14 Updated WECC Defined Facilities by adding descriptions and additional transmission lines consistent with
planning department.
06/04/14 Added Imminent Threat Trees section under Maintenance Activities. Added priority reject poles to the
Pole Inspection and Ground-Line Treatment section.
07/02/14 Updated WECC-Defined Facilities lines list based on revised list provided by System Planning.
10/06/14 Updated Line Patrols/inspections section for clarification.
12/02/14 Added utility terrain vehicles (UTV).
12/17/14 Removed Unscheduled Emergency Line Patrols from Maintenance Activities since these are
undocumented patrols. Substituted “high priority threat trees” for “imminent threat trees” for consistency
with TVMP language.
01/06/15 Added “High priority trees identified by the utility arborist will be documented on a Transmission Line
Clearing Contact sheet” for clarification on documentation of high priority threat trees.
12/22/15 Added 500 kV transmission lines 857 Hemingway-Summer Lake and 856 Midpoint-Hemingway to Path 14,
Idaho to Northwest, WECC Defined Facilities list. Removed 345kV line 802 Jim Bridger-Three Mile Knoll-
Goshen from Path 19, Bridger West, WECC Defined Facilities list. Updated plan for accuracy.
01/10/17 Removed the Transmission line worksheet since that is no longer used.
Omitted Line 855 since that is now incorporated into Lines 856 and 857.
Changed to Line #704, reflecting that Idaho Power owns the first two spans out of Brady but PacifiCorp
maintains the entire line; IPC does not maintain those two spans.
Added Line #412 to Path 55 list since the SOL is lowered for an outage on that line.
Added Huntington Wind Park–Nelson Tap section to the Line #423 description.
Added the works and “as listed in the Transmission Comprehensive Maintenance Schedule” on page 8.
Added “TRAM” and the change from transmission maintenance schedule to Transmission Comprehensive
Maintenance Schedule to more accurately reflect the tracking process.
01/24/17 Corrected change to Line #704 regarding what IPC maintains.

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This Transmission Maintenance and Inspection Plan has been approved and authorized by
the following:

Date 1/13/17

Date 1/13/17
Engineering Leader Manager, Transmission & Distribution
Engineering & Reliability

Jill Glenn Perry Van Patten

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