Preventive Maintenance Strategies for Electrical Distribution System

Presented by:Charles Alvis

Schneider Electric

· 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

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

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

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.

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.

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.

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

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.

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

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 Generatorsand…• Bonding & Grounding Systems (often overlooked)

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 andscheduled, as noted earlier.

· Arrangements for temporary electricalpower should be made, if needed.

· Above all, it is management’s responsibility for onsite safety, whether for in-house or third-party electrical workers.

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 electricalproviders should be thoroughlyqualified by management.

- An in-depth interview is suggested and applicable references obtained.

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

Code and Regulatory Compliance Requirements

Regularly scheduled electrical preventive

maintenance helps companies meet the

requirements of OSHA, NFPA 70E and other

authorities having jurisdiction.

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 localauthorities having jurisdiction

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

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.

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

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

EasyComprehensive supportPredictable operating costs

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

Infrared Viewing Windows

Enhances safety by allowing infrared inspections without the need to remove equipment covers.

Infrared Viewing Window

Allows monitoring of critical connection points.

Exceptionally valuable for areas not seen by infrared cameras.

Temperature Monitoring

SensorSensor

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

Active Asset Condition Based Monitoring

Emerging – Comprehensive Asset Monitoring

References

• National Fire Protection Association (NFPA) 70B, Recommended Practice forElectrical 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.