DESIGNING A MODERNIZED ELECTRIC DISTRIBUTION

CIRCUIT INSPECTION PROGRAMAn APPA DEED Sponsored Project

March 10, 2004Presented at the:

2004 APPA Engineering & Operations Technical ConferenceSystem Planning Committee Roundtable

San Antonio, Texas, USA

CEO

Keith Pitman, P.E.

Pitman Utility Engineering, P.C.

Phone: 315-361-5852Fax: 315-361-5853

Email: kpitman@pitmaninc.n

et

131 Sherrill RoadSherrill, NY 13461

www.pitmaninc.net

BY:

Acknowledgements

• Freeport, Long Island, New York– Special Thanks to Superintendent Hubert

“Hub” Bianco for sharing in the vision, hosting the project, and co-sponsoring the project

• APPA’s DEED program • The City of Sherrill (NY) Power & Light• Those in the distribution business• All that have attended my “training” on the

subject of “distribution circuit inspection”

Why this project?

• Need – where else can you find useful practical viewpoints and information on the subject?

• The customer and the public• Supporting critical and core utility strategic goals

– Safety– Reliability– Economic

• NESC Compliance • End product – An APPA how to guidebook to be

published.

Basic Questions Answered

• Why Inspect?

• How to Inspect and who should do it?

• When to Inspect?

• Key Definitions Given:– Circuit inspection– Basic field survey

• How to develop and implement “your” program?

Why Inspect?

• Why inspect? Here are a few of the good reasons.• A high quality distribution circuit inspection has the

potential to:– Help maintain compliance with specific NESC requirements,

including the requirement to inspect – Enhance public safety– Enhance utility personnel safety– Contribute to greater electric service reliability– Reduce exposure to claims and lawsuits– Create useful inputs for circuit maintenance and replacement

decisions/investments – Reduce the likelihood of disasters and improve disaster recovery

responses

How to Inspect?

• First, use the right people and equipment – silly leader?

• Training/qualification• Tools of the trade ranging from high-tech to

simple/manual– To obtain info– To store info – “Deficiency only” inspections and/or general condition

inspections• Depends on goals and resources of the program• General condition inspection presents an opportunity for

valuable benefits and “information overload” – proceed carefully

Important definition

• Distribution Circuit Inspection – the overall process of thoroughly examining a distribution circuit for the purpose of determining its condition and needs for maintenance or corrective actions. This process may include observation, testing, measuring, comparing, and other situation appropriate techniques relevant to the circuit component in question. It is best accomplished by individuals experienced with operating and maintaining distribution circuits similar to the subject circuits. A bona-fide distribution circuit inspection process, barring one conducted during “emergency” conditions, includes documentation – even if the documentation reflects a circuit or circuit component in satisfactory condition with no need to re-inspect at other than the usual time interval.

Another Important Definition• Basic Field Survey – the process of inspecting a distribution circuit

by making use of the human senses - primarily vision. Applicable to both overhead and underground (to the extent observable) circuitry, the basic field survey consists of observations from as many perspectives as can be practically, yet expeditiously done. The purpose of the basic field survey is to arrive at three possible conclusions: 1) a distribution circuit deficiency condition(s) exist, 2) no distribution circuit deficiencies exist, or 3) there are specific indications that inspections or tests beyond the basic field survey are necessary.

• Perhaps more useful than a “patrol” aimed at finding “obvious structural problems and hazards – Key elements of process – thinking and sincere care about the job – a

new and profound concept – not really!

When to inspect?• One extreme to the other.

– NESC (open ended) and CPUC order (super specific)– Best answer – develop your own using common sense, judgment, and peer

review• Example: Prioritized distribution circuit inspection list (top as the highest

priority):• Basic field survey of the first 2000 feet of ultra important and aging circuit #5• Basic field survey of the first 500 feet of ultra important and mildly aging circuit #3• Hammer test of wooden poles over 40 years of age in areas where poles are subject to

likely climbing by personnel• Screwdriver test of wooden poles over 50 years of age in utility defined wet areas • Thermal imaging of underground feeder tap serving hospital• Check the ground resistance of physical system grounds on multi-grounded neutral

system in utility defined high lightning areas

• Another great time to inspect – after recovery from a traumatic event

Designing or Improving Your Program?

• Gather inputs– What do you have, what do you need?– Who can help?

• Spec your program– What do you want out of it.– What should it do and look like etc.

• Go do it today?– Cost very little to starting building up a great program– Ask yourself – can I afford to wait?

Designing or Improving Your Program – the Inputs?

– Currently used utility inspection forms (hard copy and/or electronic storage).

– An inspection tool/equipment inventory– Circuit maps and one line diagrams– Circuit maintenance records– Historical circuit inspection historical records– Historical circuit reliability data– Circuit electrical operating parameters

• Examples: Typical loading, maximum allowable loading, minimum allowable voltage, etc.

– Work experience records of personnel presently of previously involved in distribution circuits

– The current and prior* versions of the National Electrical Safety Code (NESC)– Commitment from management and officials to prioritize distribution circuit

inspection program planning and development

Designing or Improving Your Program – the Specs?

– Be realistic and practical – capable of actually being carried out using the personnel, tools/equipment, and resources that are likely to be available.

– Make use of prioritization and acknowledgement that certain distribution circuit inspections are more useful and critical to the utility than others

– Make use of at least some modern technologies for obtaining inspection information or storing/recording it.

– Have a certain specific inspection schedules determined in advance, acknowledging that distribution circuit inspection is not optional and should only be deferred under exceptional circumstances as determined by utility management.

– Use and provide training for qualified inspectors and clearly define “qualified”– Permit temporary suspension of normal inspection practices during emergencies – and

pre-specify the nature of the suspensions for foreseeable emergencies– Seek to identify distribution circuit deficiencies and problem/failure pre-cursors and

promote the sharing of problem/failure pre-cursor information within the utility– Require post-traumatic event inspections – at least for certain foreseeable trauma

categories– Have some means of quality control such as audits, peer reviews, or random re-

inspections– Make use of some random inspections, unless there is a compelling practical reason that

making such efforts wasteful of resources or impractical

Implementing Your Program – formalize and document?

– This can not be stressed enough• Prove to yourself, your friends, and your enemies

if necessary that you have a solid circuit inspection program

– Where is the documentation?– Where is the utility policy?– How can the program be passed from

generation to generation?