As presented at AIST 2014, A comprehensive, routine preventive maintenance and testing program is the way to ensure your facility's electrical equipment and components operate properly and for as long as possible. "Preventive Maintenance Strategies for Power Distribution Systems" will present how to implement an effective program at your facility. The presentation will also show you how regularly scheduled preventive maintenance can improve operational safety and energy efficiency within your organization.

1. Preventive Maintenance Strategies for
Electrical Distribution System
Presented by:
Charles Alvis
Schneider Electric

2. The cost of ignoring maintenance and testing
Recommended steps to an effective electrical preventive maintenance
program:
- Assess the current state of the electrical system
- Maintenance and testing protocol
- Planning for outages
Considerations for outsourcing
- Is in-house staff qualified, as defined by NFPA 70E?
- Do they have the capability to make corrective recommendations
for issues that may arise?
Fixed Cost Service Agreements
Multi-year service plans help make maintenance easy for facilities
Predictive Maintenance Technology and Trends
Preventive Maintenance Strategies

3. The Cost of Ignoring Maintenance
“A well-administered Electrical Preventive Maintenance
program:
Reduces accidents
Saves lives
Minimizes costly breakdowns and unplanned outages
Impending troubles can be identified, and solutions
applied, before they become major problems requiring
more expensive, time-consuming solutions.”
NFPA 70B-2013 Ed., Section 4.2.1

4. The Cost of Ignoring Maintenance
Section 4.2.7 goes on to state:
“An Electrical Preventive Maintenance (EPM) program
satisfies an important part of management’s
responsibility for keeping costs down and production
up.”
Having a preventive maintenance program in
place can reduce the risk of unplanned
downtime by as much as 66%. Source: IEEE

5. Recommended Steps:
Assess the Current State of the Electrical
System
• An up-to-date one-line
diagram of the electrical
system provides clear and
precise information concerning
the exact interconnections of
all electrical equipment.
• Due to modifications made to
the electrical infrastructure,
many facilities do not have a
current drawing.

6. Recommended Steps:
Assess the Current State of the Electrical System
• A licensed professional electrical engineer should be contracted
and commissioned to create and maintain current electrical
one-line diagrams and equipment name plate data.
• Prior to initiating a preventive
maintenance program, have a
short circuit analyses, a time-
current coordination study, and
an arc flash analysis of all of the
power distribution systems to
ensure equipment is properly
rated, set and labeled.

7. Recommended Steps:
Maintenance and Testing Protocol
• A comprehensive preventive maintenance and testing program
should incorporate detailed policies, procedures, and
maintenance activities for the entire electrical power
distribution system, regardless of the manufacturer.
• NETA-MTS, NFPA 70B and OEM operations and maintenance
manuals can provide recommended guidelines for developing
the work scopes as frequency for performing maintenance and
testing.
If OEM manuals are not readily available,
contact the manufacturer or check online.

8. Recommended Steps:
Maintenance and Testing Protocol
The recommended maintenance and testing interval may need to
be altered if any of these factors exist:
• Potential to safety of equipment failure
• Operating environment and equipment condition
• Operating load and ratings
• High repair cost equipment
• Cost of down-time to production
• Performance history of equipment

9. Recommended Steps:
Maintenance and Testing Protocol
Any specific maintenance of separate pieces
of electrical equipment does not guarantee a
completely coordinated and reliable power
distribution system as intended and
necessary.

10. Recommended Steps:
Maintenance and Testing Protocol
The facility’s management needs to clearly communicate to the
service provider:
Which equipment is included in the maintenance program
The specific order the
electrical equipment
should be removed from
service for maintenance
The detailed scope of
work for each piece of
equipment or component

11. Recommended Steps:
Maintenance and Testing Protocol
Recommended items or equipment to Incorporate into a
Preventive Maintenance Program:
• Monitoring equipment
• Metering equipment
• Protective relays
• Service-entrance
switchgear
• Circuit breakers
• Switchboards
• Panelboards
• Motor control centers
• Transformers
• Automatic transfer switches
• UPS Systems
• Busway
• Optional Stand-by
Generators
and…
• Bonding & Grounding
Systems (often overlooked)

12. Recommended Steps: Planning for Outages
With FEW exceptions, electrical
equipment should NOT be cleaned,
inspected, maintained, serviced,
or tested while it is energized.
When planning for an outage, ‘critical’
equipment should be identified and
scheduled, as noted earlier.
Arrangements for temporary electrical
power should be made, if needed.
Above all, it is management’s
responsibility for onsite safety, whether
for in-house or third-party electrical
workers.

13. Considerations for Outsourcing
• Facility management needs to insure that
electrical workers are experienced in the
specific equipment or system that is to be
maintained.
• Very few companies have in-house staff who
have the experience to service all of the
electrical equipment within the facility’s
electrical power system.
• Proposed third-party electrical
providers should be thoroughly
qualified by management.
An in-depth interview is
suggested and applicable
references obtained.

14. Considerations for Outsourcing
Personnel performing the maintenance activities need to
be qualified as defined by OSHA and NFPA 70E.
Fundamental requirements include:
• Complete understanding of equipment,
the required work scope and electrical
hazards present.
• Proper use of protective equipment,
tools, shielding and test equipment
as well as precautionary techniques.
• Discipline and decision making
skills to determine risk and ability
to maintain a safe work environment.
Photo Courtesy of Oberon

15. Code and Regulatory Compliance Requirements
Regularly scheduled electrical preventive
maintenance helps companies meet the
requirements of OSHA, NFPA 70E and other
authorities having jurisdiction.

16. Code and Regulatory Compliance Requirements
Conditions that may warrant preventive maintenance be
performed more frequently than the OEM’s
recommendations include:
●Environmental conditions,
including humidity, corrosive
atmosphere, dirt or dust
●Equipment runs constantly
or with heavy loads
Requirements of local
authorities having jurisdiction

17. Maintaining quality records of maintenance (and repair)
activities support regulatory compliance as well as provide
trending data.
●Helps identify potential problems to avoid equipment
breakdown.
●Enables management to track costs of maintenance
activities over time.
Code and Regulatory Compliance
Requirements

18. In addition to maintenance records, having the
following documentation available* will prove helpful
in the event of an electrical incident.
● Tools, materials and equipment needed
● Average time to perform tasks
● Reference manuals
● Past test reports
● Past incident reports
● Record of repair work
Code and Regulatory Compliance
Requirements
For each piece of
equipment being
tested.

19. Fixed-costs service agreements are a growing trend to
manage increasingly complex electrical power distribution
systems or systems with multiple brands of equipment.
●In addition to meeting regulatory requirements, these plans
offer the flexibility to customize a scope of work and term.
●A fixed-cost service plan avoids fluctuations to the maintenance
budget
●Billing can usually
be structured to
provide a fixed >
payment schedule.
Fixed Cost Service Plans

20. Fixed Cost Service Plans
Typically Three Levels Of Outsourced Field Support
Maintenance
Service
Emergency on
Site Response
Replacement
Parts
(All Inclusive)
A New Approach
for Maintenance

21. Predictive maintenance techniques safely provide condition
status to help anticipate and plan maintenance activities.
Predictive maintenance solutions detect early
warning signs and help prevent downtime.
Predictive Maintenance Solutions

22. Infrared Viewing Windows
Enhances safety by allowing infrared inspections without the need to remove equipment covers.
Infrared Viewing Window

23. Allows monitoring of critical connection points.
Exceptionally valuable for areas not seen by infrared cameras.
Temperature Monitoring
SensorSensor

24. Detects impending insulation breakdown in MV equipment, which can lead to costly equipment
damage and downtime.
Coupling
Capacitors
RF CTs
Bushing Sensor
Partial Discharge Monitoring

25. Active Asset Condition
Based Monitoring
Emerging – Comprehensive Asset Monitoring

26. References
• National Fire Protection Association (NFPA) 70B, Recommended Practice for
Electrical Equipment Maintenance.
• National Fire Protection Association (NFPA) 70, National Electrical Code.
• National Electrical Manufacturer’s Association (NEMA) Standard AB4, Procedures for Verifying
Field Inspections and Performance Verification of Molded-Case Circuit Breakers.
• National Electrical Testing Association (NETA), Maintenance Testing Specifications for Electrical
Power Distribution Equipment and Systems.
• IEEE Standard 902-1998, IEEE Guide for Maintenance, Operation, and Safety of Industrial and
Commercial Power Systems.
• IEEE Standard 142-2007, IEEE Recommended Practice for Grounding of Industrial and
Commercial Power Systems.
• National Electrical Manufacturer’s Association (NEMA) Standard MG1.