Maximizing the Return on your Infrared Electrical Inspection Investment

InfraMation 2012 Application Paper Submission

Bob Fink  

A1 Infrared Inspections 

ABSTRACT  

Infrared thermography is proven to be the best way to inspect and maintain electrical systems and can  guarantee savings in electrical usage, downtime, and fire and loss prevention. Whether you choose to  contract for an infrared professional, or handle the job in-house, you will be investing a sizable amount of  money and time. This discussion will present methodology to maximize the efficiency and effectiveness of  your infrared electrical inspection. It will include the basic parameters for any electrical inspection in general  as well as site-specific recommendations.  

BASIC PARAMETERS  

Every IR electrical inspection will have three basic components: a) the infrared technician; b) qualified  personnel to open and close all equipment to be inspected; and c) individual(s) familiar with the locations of  all panels and equipment included in the defined scope of the inspection. Quite often one person will play multiple roles. For safety, the inspection team should always include two or more persons.

The Infrared Technician – This is the person who will be using the IR imager and documenting and  interpreting the findings. In some instances, the IR technician will also be qualified to assist in  opening panels.

Qualified Personnel – One or more persons properly trained and qualified to open live electrical  panels. These persons should be familiar with the mechanics and operation of all equipment being  inspected, as well as NEC and OSHA safety regulations. More often than not, one or more of these  persons are also the individuals familiar with the facility and the location of all equipment to be  inspected.

Inspection Coordinator – Individuals familiar with the facility and the locations of all equipment to be  inspected as well as any specific scheduling requirements. These individuals should also be properly  trained in safety and emergency procedures. Most often these responsibilities are also fulfilled by the  persons acting as Qualified Personnel.

SCHEDULING  

The first step of your IR inspection is, of course, scheduling. A little forethought at this stage can greatly  improve the overall effectiveness of your inspection.

Scheduling Considerations – General

Peak Loads – Scheduling your inspection during peak load and production times is essential in  maximizing its effectiveness. Although this may pose challenges, the benefits almost always outweigh  the extra effort. There are several site-specific exceptions that will be discussed later.

Personnel – Make sure the necessary persons are going to be available. Things will go much  smoother if the lead electrician is not on vacation.

Site-Specific Scheduling Considerations – These factors will be discussed later in this paper.

PRE-INSPECTION  

A little extra planning at this stage can dramatically increase the efficiency of your inspection by helping to avoid delays and save time. Whenever possible, it is best to include individuals who will be performing the inspection in the discussion and planning as well as management.

Define the Inspection Parameters – Make a list of all locations and panels to be inspected. Be sure  to include outdoor and rooftop equipment as well as any off-site locations, i.e.; water treatment  facilities, well heads, lift stations, etc. This is especially true if you are contracting for your infrared  services. As a general rule, the thermographer is not going to be familiar with your facility.

Review Panel Labeling – This is a good time to make sure that all panels being inspected have an  in-house label. These labels will help identify panels in which anomalies are found and avoid  confusion at the time of repairs.

Review Equipment Details – Check to ensure that all personnel involved in opening panels are  familiar with panel locations, mechanics, and opening procedures. Make sure any special wrenches  or tools that are needed will be available, as well as any keys required for access. Consider installing  viewports in large and high voltage panels for easier, safer access. Determine if any panels can  safely be opened prior to the inspection. This is often an easy way to maximize efficiency in your  inspection. Some facilities have panels in closets or rooms that can be secured from unauthorized  access. These panels can be opened in advance of the inspection to save time.

Coordinate with Utility Providers and On-Site Contractors – If your list of equipment to be  scanned includes utility-owned transformers, be sure to call ahead and schedule someone to open  their equipment on the day of the inspection. Most providers will be glad to have their equipment  inspected as long as you give them advance notice. The same holds true for on-site contractors such  as elevator maintenance companies.

Coordinate Internally – Inform all security personnel, department heads, managers, crew leaders,  etc. in advance of the inspection. Discuss possible scheduling, production, safety, and personnel  conflicts that may arise.

Review Safety Procedures – Review all safety procedures and make sure all personnel involved  have the proper Personal Protective Equipment on hand at the time of the inspection. Also review emergency procedures to ensure all personnel involved know what action to take in the case of an accident. 

Consult Your Thermographer – Should questions arise during your planning, do not hesitate to  contact your thermographer. It is what you are paying him for.

DETERMINING THE INSPECTION AGENDA  

The order in which you conduct your electrical system inspection can maximize both its effectiveness and  efficiency. Some factors that affect nearly every commercial and industrial electrical inspection agenda  include:

Weather – When the forecast calls for clear skies, bright sun, and high ambient temperatures,  outdoor equipment with exposed elements (substations, transmission lines, pole-mounted  transformers, arresters, insulators, fuses, etc.) are best inspected before dawn or after sunset to  minimize the effect of solar loading. Although an experienced thermographer with proper equipment  can find problems despite solar loading, the more the effect is minimized, the quicker and more  accurate the diagnosis will be. Check the daily forecast for rain and schedule accordingly. Most IR  cameras can handle light rain (a plastic grocery bag makes a handy impromptu lens protector); however, removing panel fronts or opening cabinets in the rain is never a good idea and should be avoided.

Production Schedules – Attention should be paid to all production schedules in your facility. For  example, in some food, dairy, and snack production as well as some manufacturing facilities, the  departments at the beginning of the production line (unloading, mixing, etc.) are done for the day andcleaning up long before departments at the back end of the production line (packaging and shipping). There are some other site-specific considerations that we shall discuss in a few moments.

Load Distribution – Consideration of your facilities daily load distribution will also help maximize  your infrared investment. For example; in residential applications and hotels, panels feeding individual  units or guest rooms have the largest loads in the evening hours when they are occupied, so a  second shift inspection of these panels may be in order. Large HVAC systems (chillers, cooling  towers, and associated pumps) are best inspected in late afternoon in warm weather when they are  working the hardest.

Panel Location/Facility Layout – In large facilities, a lot of time can be wasted getting from place to  place. Try to arrange a route through the facility that avoids doubling back too much. Multi-floor  buildings are best done floor-by-floor from the top down if possible. Inspections of large open  buildings such as warehouses and shipping facilities are easiest if the perimeter is done first followed  by the interior. In general, after considering the above mentioned criteria, the best place to start any  electrical inspection is at the service entrance(s) and main switchgear(s) and then move on to the  sub-panels.

Equipment Prioritization – It is always advisable to inspect all of your equipment, but occasionally  budgetary or time constraints may require a prioritization paradigm. In these situations, an advance  consult with your infrared professional can be extremely beneficial. Aside from site-specific equipment  critical to production, a general priority list would be:

Substation (if applicable) 

Service Entrance to Building(s)  

High Voltage Transformers  

High Voltage Switchgear (if applicable)  

Emergency Generator Switchgear and Auto Transfer Switches  

Main Switchboards/Distribution Panels  

Bus Ducts, Wireways, and Wire Troughs  

Motor Control Centers  

Sub-Panels  

Control Panels  

Low Voltage Transformers  

Contactors  

Service Disconnects 

METHODOLOGIES FOR SPECIFIC TYPES OF EQUIPMENT  

Some types of electrical equipment can pose challenges to infrared inspection. The first challenge to be met  is of course, safety. A complete, accurate, and effective infrared inspection requires that panels and  equipment be opened while energized and under load to expose termination and contact points. Always  follow all recommended and required safety procedures. Some panels and switchgear, by design, cannot be  opened while energized. In these situations, smaller switches and control panels can sometimes be de energized, opened, and re-energized while open to permit infrared inspection. In some cases, especially if the  load has been large and constant prior to opening, an infrared examination can detect anomalies without re energizing the equipment if performed before the equipment has a chance to cool. 

Infrared Inspection Viewports – For equipment over 480 volts, panels that are infrared-inspected  frequently, and panels that are large or extremely difficult or unsafe to open, viewports can be  installed that allow for easy, quick, and safe infrared inspection. Consult with your electrical  contractor, supplier, infrared contractor or consultant. 

Outdoor Equipment – As mentioned above, outdoor equipment is best inspected on overcast days  or as early in the day as possible for maximum accuracy. 

Main Switchboards/Distribution Panels – As well as inspecting fuse clips and breaker terminals,  rear and/or side panels should also be removed if possible. This allows inspection of internal bus  bars, wire connections, heaters, etc.

Overhead Bus Ducts – Overhead bus ducts and bus-mounted equipment are often critical to facility  operation and always difficult to inspect. The most efficient method is to first make an infrared  inspection from floor level, noting any anomalies in the bus and bus-mounted equipment. Disconnects  showing anomalous surface temperatures can then be singled out for further infrared analysis or repair.

SITE SPECIFIC RECOMMENDATIONS  

Remember the following points to increase the effectiveness of an infrared inspection in various facilities.

Hospitals – There are several considerations unique to infrared inspections in hospitals; Back-up power supply is critical in hospitals. All primary automatic transfer switches should  be inspected under both normal and emergency generator supply.

Hospital inspections are best performed in warm weather when cooling demand is greatest.  Qualified personnel should be on hand to power up and test backup chillers and their associated equipment. In addition, if possible, a winter inspection of electric heating systems  is also wise. Surgical suites often pose challenges. This is one instance in which the infrared inspection  will probably be conducted under minimal load conditions. Coordination with surgical unit staff  will be necessary. Many hospitals have medical office buildings attached. It is always advisable to make the  effort of coordinating with the individual tenants in advance to facilitate inspection of panels in  their offices.

Hotels – Thoughtful planning of a hotel inspection will help save time and ensure accurate results.  ∙ In large hotels with extensive common areas, HVAC is of prime concern. As with hospitals, it  will be best to perform the infrared inspection during warm weather. As mentioned above, panels feeding guest rooms are best inspected in the evening hours  when most are occupied. Large kitchens should be inspected early in the day when most cooking is done and kitchen  loads are at their highest. Remember to coordinate with elevator contractors if necessary. 

Server Farms/Switching Centers, Airport, Broadcast, and Emergency Services Critical Power – These facilities present another instance when the infrared inspection is performed during minimal  loads (usually 3rd shift). This is done to limit the impact of an accidental power interruption. These are  also instances where transfer switches and their associated switchgear should be inspected under  both normal and emergency supply, whenever possible. Advance consultation with your infrared  professional is highly advisable in these situations.

SUMMATION  

Implementing the discussed methods and adapting them to your unique situation will improve the efficiency  and accuracy of your infrared electrical inspection, giving you the best returns on your time and money and  ensuring maximum energy cost savings, safety, and loss prevention.  

ABOUT THE AUTHOR  

Bob is a Level II thermographer and has 19 years experience in the field.