Sousley - Leestown Combined Test Report.pdf

Electrical Maintenance & Testing ProjectElectrical Maintenance & Testing Project

CoverCover

Submitted by

Veterans Affairs Medical Center Sousley Division

Lexington, Kentucky

Contract No. VA36C24920P0633

Contracting Officer: Michael Brown

Phone No: (615)225-5975

Jerry M. Parks Jr., Project Manager

Project Test Report

December 1-5, 2020

845 Long Branch Circle

Sugar Hill, Georgia 30518

P - (678)546-9393, F – (678)828-5903

337 Sundance Trail

Liberty Hill, Texas 78642

P - (512)484-5594 in cooperation with

Slocum & Associates

Electrical Maintenance and Testing Project Contract No. VA36C24920P0633

Veterans Affairs Medical Center – Sousley Division

Lexington, Kentucky December 1-5, 2020

Section 1 Electrical Testing and Maintenance Summary

Section 2 Publications/Exhibits

Section 3 Electrical Test Records

Section 4 Specialized Tools & Equipment, Testing Specifications and Licenses/Certifications (Digital Version Only)

Table of Contents

1 | P a g e

Electrical Testing & Maintenance Report Summary

General

Slocum & Associates, in cooperation with SDV Services Inc., provided electrical testing and maintenance services at the Veterans Affairs Medical Center – Sousley Division in Lexington, Kentucky on December 1-5, 2020 under contract number 36C24920P0633. All services were conducted in accordance with contract specifications, industry standards, NFPA 70B and manufacturer’s recommendations.

The types of equipment tested during this testing session included:

Medium Voltage Switches

Medium Voltage Oil-Type Transformers

Low Voltage Switchboards and Circuit Breakers (select areas)

Automatic Transfer Switches

Motor Control Centers

Test results were compared with manufacturer’s recommendations for each specific equipment item and type.

This report consists of the following:

Section 1 Electrical Testing and Maintenance Report Summary

Section 2 Publications/Exhibits

Section 3 Electrical Test Records

Section 4 Thermographic Records

Section 5 Licenses, Certificates, Specialized Tools & Equipment

Thermographic Inspection (Infrared)

In addition to regular testing procedures, infrared scan procedures were used wherever possible to determine serviceability and reliability of the equipment inspected to include panelboards.

The infrared services were conducted using a FLIR T440 thermal imaging camera.

While infrared technology can be an invaluable tool in predictive maintenance, it is not without limitations. Reflectivity, background, material emissivity and ambient temperature are among many factors that can influence thermal readings. As a result, reported temperature readings

Slocum & Associates in cooperation with

2 | P a g e outlined in this report should not be viewed or used in terms of absolute temperature readings.

Instead, the readings should be viewed in terms of trends and relationships with other equipment components or like materials.

Supplemental tests were performed wherever possible and on an as-needed basis. These tests consisted of recording circuit loads and conducting Voltage Drop Tests. Circuit loads were monitored to assist in identifying potential phase imbalances or overload conditions. Voltage Drop tests were conducted to determine potential contact resistance issues. Both tests are extremely valuable in helping to determine potential sources of temperature variances.

The Individual Thermographic Report section of this report provides a report on each piece of equipment with a deficiency to include among other things:

Thermal image

Visual image

Thermal readings

Location

Condition and cause

Priority level

Recommended action

Repair Priority Levels

It is important to note the “temperature rise” documented on each page of the report is stated for example, “At least 17°C over reference.” This is stated this way as we know for certain the temperature is at least that value. What we don’t know is the true temperature at the point of the problem as other pieces of equipment or hardware shield us and the camera from that view.

We also know at some point in time the equipment item will fail based on the reported condition but cannot with any certainty predict when that will happen. Therefore, every documented issue is important and should be carefully considered.

Many factors or questions need to be addressed when attempting to establish a repair priority level to resolve documented issues. In random order, some general guidelines or questions you might consider in assigning a repair priority level are:

1. How critical is the piece of equipment?

2. What are the ramifications if it fails? What areas will be affected?

3. Is there a personnel hazard or danger?

4. Can the issue lead to collateral damage of related equipment either upstream, downstream or within the same area?

5. What is the cost of resolving the issue using a controlled, scheduled shutdown versus an emergency repair/replacement of the equipment item should the equipment fail unexpectedly?

6. Are resources (personnel, contractors, money, etc.) available to make the repairs?

3 | P a g e

The thermographer cannot readily address such issues or make such determinations. As a result, repair priority levels need to be determined by the VA personnel with the ability to address such questions or those pertinent to their facilities. Note – answers to questions 1-5 should help to overcome or support obstacles encountered with question 6.

Findings & Recommendation

Outlined below are the findings and related recommendations for issues noted during this testing session. These findings are in random order and not prioritized based on severity of the issue.

1. Electrical System Condition

Issues

There are some notable areas of the electrical system in need of upgrading based on their poor condition, being well over 25 years of age based on industry standards and having surpassed the threshold of its 15-year service life outlined in the VA Electrical Design Manual reference below.

VA Electrical Design Manual Reference

1.15.4 AGE AND PHYSICAL CONDITION

(b) The equipment should be capable of remaining in use for a minimum of 15 years of additional life or having 60 percent of remaining life, if not the equipment shall be replaced.

Those areas in need of upgrading are:

a. Building 28 – MP28 Switchboard and MP28A Panel.

The MP28 main circuit breaker failed to trip during overcurrent testing.

Panel MP28A had a couple of issues: 1) the panel main breaker had difficulties in resetting after opening the breaker. This same breaker has previously been repaired.

Additionally, seven (7) branch circuit breakers were found frozen. Efforts to free the operating mechanisms were not successful with most breakers failing to open or delayed in opening. Those breakers are:

▪ 28LP15

▪ 28LP3

▪ 28LP10

▪ 28LP18

▪ 28LP17

▪ 28LP4

▪ 28LP1

These conditions where the breakers fail to open or are delayed in opening have the potential for a potentially catastrophic fire or significant arc flash incident.

4 | P a g e

It should be noted the MP28 switchboard and MP28A panel are well over twenty-five

(25) years of age. Noted conditions are directly attributable to the age of these components raising the question of reliability in regards to the ability of the equipment to properly operate and safely protect the building and its occupants.

Their critical nature and state of condition suggest this equipment should be assessed a General Condition Code of “F” using the Facility Condition Assessment guidelines. Using the characteristics in developing the code levels, the basis for application of the “F” code for this equipment is as follows:

1. Being the primary and/or emergency source of power to the related building, failure is critical to the operation of this facility.

2. The equipment is in poor condition.

3. It has exceeded its useful service life by both industry and VA standards.

4. Requires immediate attention due to the unpredictability of future performance and reliability.

Upgrading or refurbishing this equipment does not appear to be feasible for a couple of reasons:

1. Technical obsolescence creates issues in relation to arc flash hazards and the ability to minimize associated hazards as discussed previously.

2. Replacement is inevitable. Delaying replacement increases the risk of failure in addition to higher replacement costs in the future.

For these reasons it would seem prudent to assign a cost ratio of greater than 1.0 meaning it would be more costly to repair than replace.

b. Building 4 – Panel DP4

This panel is similar to MP28A discussed above. Several circuit breakers were difficult to trip and remain sluggish to operate even after significant exercising. Again, the panel and these breakers are roughly forty (40) years of age presenting the same reliability questions as mentioned above.

Supplemental Notes on Equipment Aging

Replacement parts are becoming increasingly more difficult to obtain due to age and technical obsolescence. More importantly equipment of this age and condition raises the question of reliability in regards to the ability of the equipment to properly and safely protect the facility. Careful consideration should be given to upgrading the older equipment throughout this facility.

As electrical equipment ages, the associated risk of a failure increases significantly. Such failures usually occur without prior warning and can be potentially catastrophic. Repairing or replacing aged equipment is another issue due to obsolescence or non-availability of parts. In the event of a failure, there is a great possibility parts will not be available or will have significant lead times. As an example, SDV found a defective main switch in a federal

5 | P a g e building that took 6 months to acquire a replacement part due to technical obsolescence.

This can lead to very costly repairs and extended down time for equipment and related circuits.

Included in section 2 to this report is an article presented by three professional engineers (PEs) specializing in electrical distribution systems – “Renovating Electrical Distribution Systems” by Syed M. Peeran, PhD, PE; Mario Vecchiarello, PE; and Jeff Romeo, PE. The first page of this article references the hazards of aging electrical systems and the unpredictability of equipment exceeding its useful service life. Equipment identified in this report has far exceeded this service life without upgrade and has this element of unpredictability regardless of past performance or testing.

Recommendations

Due to the age, obsolescence or condition of the above-referenced systems, a project should be initiated to bring these noted areas into a safe and reliable state as follows:

a. Switchboard MP28 and panel MP28A should be replaced in their entirety. While only the Main circuit breaker in switchboard MP28 failed to operate properly, the remainder of the switchboard contains circuit breakers well over forty (40) years of age.

b. While not as mission critical as the equipment in building 28, panel DP4 in building 4 should be replaced in its entirety due to age and condition. At a minimum, the two above-mentioned circuit breakers should be replaced.

2. Additional Equipment Conditions

Several other buildings contain equipment approximately forty (40) years of age and are in poor condition. Those areas are as follows:

a. Building 25 – Panel MP.

b. Building 2 – MDP panel.

c. Building 4 – Electrical panels throughout the building. Hardware is in poor condition.

d. Building 27 – Majority of the panels throughout the building.

e. Building 22 – Panel MP22.

A project should be initiated to replace this aged equipment to ensure continued safe and reliable performance.

6 | P a g e

3. Adverse Conditions

Two (2) areas were noted where equipment is subject to adverse conditions for varying reasons as outlined below:

▪ Building 2 Main Switchboard – this switchboard is located in a mechanical space where chemicals are used in mechanical equipment operations. The switchboard is exposed to such chemicals that leads to corrosion and a reduced service life as pictured below.

Enclosed in the Publications section of this report is a Square D publication concerning placing electrical equipment in adverse environments with guidelines for properly protecting such equipment.

▪ Main Vault, Building 3 – the main electrical vault for building 3 is located in a room on the outside wall of the building. The ambient temperature in this vault was in the low 50s and without thermostatically-controlled heat. Circuit breakers exposed to abnormal ambient operating temperatures such as this can experience hardening of grease in the internal operating mechanisms. This condition can cause the circuit breaker to either fail to open or be delayed in opening in response to a fault with the potential for a catastrophic failure. A delayed response in opening (seconds versus cycles) can lead to a sustained arc while failing to open can lead to a fire.

Both have the potential for a catastrophic failure if left uncorrected.

▪ Main Vault, Building 29 – similar to building 3, the building 29 main electrical vault is located in a room on the outside wall of the building. The ambient temperature in this vault was in the low 50s and the thermostatically-controlled heat device was not working. Circuit breakers exposed to abnormal ambient operating temperatures such as this can experience hardening of grease in the internal operating mechanisms. This condition can cause the circuit breaker to either fail to open or be delayed in opening in response to a fault with the potential for a catastrophic failure. A delayed response in opening (seconds versus cycles) can lead to a sustained arc while failing to open can lead to a fire. Both have the potential for a catastrophic failure if left uncorrected.

7 | P a g e

▪ Building 2 Main Switchboard – this switchboard was identified previously as needing to be replaced. The replacement switchboard should be relocated to an area removed from the chemical environment or a shell enclosure be constructed over it containing a conditioned air system to prevent corrosion and allow for a normal service life.

▪ Main Vault, Building 3 – the main electrical vault for building 3 needs to have a conditioned air system installed to maintain a constant temperature. This will help to extend the service life of the recently-installed equipment and prevent breakers from failing to open or being delayed in opening as mentioned above.

▪ Main Vault, Building 29 – the main electrical vault for building 29 needs to have the installed heater repaired to maintain a constant temperature. This will help to extend the service life of the relatively new equipment and prevent breakers from failing to open or being delayed in opening as mentioned above.

4. Improper Working Clearance

Issue

The main switchboard in building 69 has been placed directly against the wall as represented by the picture to the right. National Electric Code section 110.26(A)(1) requires a minimum 30” working clearance outlined below.

NEC Reference 110.26(A)(1)(a) Dead-Front Assemblies

(a) Dead-Front Assemblies. Working space shall not be required in the back or sides of assemblies, such as dead-front switchboards or motor control centers, where all connections and all renewable or adjustable parts, such as fuses or switches, are accessible from locations other than the back or sides. Where rear access is required to work on nonelectrical parts on the back of enclosed equipment, a minimum horizontal working space of 762 mm (30 in.) shall be provided.

Exhibit 110.9

Distances measured from the live parts if the live parts are exposed or from the enclosure front if the live parts are enclosed. If any assemblies, such as switchboards or motor-control centers, are accessible from the back and expose live parts, the working clearance dimensions would be required at the rear of the equipment, as illustrated. Note that for Condition 3, where there is an enclosure on opposite sides of the working space, the clearance for only one working space is required.

In the case of this switchboard installation, there are bus connections located in the rear of the enclosure that cannot be serviced from the front as they are blocked by other installed equipment (circuit breakers, support structures, secondary conductors, etc.).

Any attempts to service these connections as well as clean the rear portion of the enclosure from the front would require extensive disassembly of circuit breakers and secondary conductors that clearly is not the intent of the manufacturer or the NEC.

8 | P a g e

There appears to be confusion and misapplication related to installation guidelines of similar “dead-front switchboards” throughout the country based on our findings. The National Electric Code (NEC) defines “dead front” as “without live parts exposed to a person on the operating side of the equipment.” The recently-installed main low voltage switchboard located in the basement of the building is a “dead-front switchboard” based on this NEC definition. Operating personnel are protected from the energized components when covers are in place. However, this definition makes no reference to working space requirements.

NEC section 110.26(A)(1)(a), Dead-Front Assemblies (outlined below) uses this definition and applies other qualifying factors or elements in determining working spaces around such assemblies. Those factors or elements are:

1) Connections,

2) Renewable or adjustable parts, such as fuses or switches, and

3) Accessibility from locations other than the back or sides.

Additional clarification regarding work space requirements is provided in Exhibit 110.9 further down in NEC Section 110.26(A)(1)(a). It states, “If any assemblies, such as switchboards or motor-control centers, are accessible from the back and expose live parts, the working clearance dimensions would be required at the rear of the equipment.” The switchboard in question does have covers providing rear access that expose the switchboard bus components. This installation clearly meets these conditions requiring a minimum 30” horizontal working space.

Recommendation

The main switchboard in building 69 needs to be relocated to provide the minimum 30” horizontal working distance as required by NEC Section 110.26(A)(1)(a). This is necessary to facilitate proper maintenance and servicing of the bus and other components of the switchboard to include cleaning. Proper working clearance should be a point of emphasis for all future installations.

5. Transformer Negative Pressure

The recently-installed PMT-75 transformer was found with negative pressure of roughly a -2 psi. Negative pressure has the potential for moisture and air to be pulled into the oil compartment. This can lead to “bubbling” with the potential for a flashover and catastrophic failure.

Recommendations

The oil tank for the PMT-75 transformer needs to have a positive pressure applied as outlined in manufacturer’s recommendations. This can be done by pulling a vacuum on the tank and filling the space between the oil and the top of the tank with a nitrogen blanket.

9 | P a g e

6. Transformer Oil Test Results

Test Results

Oil samples were taken of all medium-voltage oil-type transformers. Each sample was tested using dissolved gas analysis (DGA). All test results were found to be well within established test limits. This is primarily due to relatively recent replacement of the majority of the transformers.

Complete laboratory test results have been incorporated into the test records for the medium-voltage transformers located in tab 3 to this report.

While trending of current to previous test results would not provide any relative or predictive trends at this point, future testing sessions should consider incorporating a trend analysis of oil test results. This has the potential for early identification of transformer problems helping to minimize damage and related expense of any issues.

7. Equipment Pads at Grade Level

Several concrete equipment pads (transformers, S&C switches, etc.) were previously reports as being at grade level allowing water, dirt and debris ot freely flow through the enclosure leading to premature corrosion and enclosure deterioration.

This condition has been corrected. However, the base of the enclosures has not been sealed or caulked to further block this water, dirt and debris from penetrating the enclosures.

All transformer and switch enclosures need to have their bases sealed with a water-resistant caulk.

8. Variable Frequency Drives (VFD)

These buildings contain a considerable number of variable frequency drives (VFD) in lieu of traditional motor starters. Harmonics (voltage and current) are introduced into the electrical system by VFD power supplies along with those generated by computers and similar electronic devices. Harmonics studies are often performed to determine the impact of harmonics in the electrical system and potential means of mitigation or reduction. It appears such a study has not been performed at this facility.

10 | P a g e

Below is an excerpt from Eaton Corporation’s white paper, “Harmonics in Your Electrical System,” regarding the potential impact of harmonic loads:

Eaton White Paper Excerpt

Most power systems can accommodate a certain level of harmonic currents but willexperience problems when harmonics become a significant component of the overall load. As these higher frequency harmonic currents flow through the power system, they can cause communication errors, overheating and hardware damage, such as:

• Overheating of electrical distribution equipment, cables, transformers, standby generators, etc.

• High voltages and circulating currents caused by harmonic resonance

• Equipment malfunctions due to excessive voltage distortion

• Increased internal energy losses in connected equipment, causing component failure and shortened life span

• False tripping of branch circuit breakers

• Metering errors

• Fires in wiring and distribution systems

• Generator failures

• Crest factors and related problems

• Lower system power factor, resulting in penalties on monthly utility bills

A copy of the entire white paper has been provided in section 2 to this report.

A project should be initiated to perform a harmonics study to confirm the presence and levels of harmonic loads to include transformers with unusually high sound levels that may be overheating due to harmonics. This study could be performed in conjunction with the above-referenced arc flash study.

Any issues should be corrected using the following Eaton guidelines outlined in the section 2 white paper:

a. Oversize the neutral wiring,

b. Install separate neutral conductors,

c. Install DC power supplies in equipment that are not affected by harmonics, or

Install K-type transformers capable of handling harmonic loads.

9. Overhead Water Pipes

The ATS/LS automatic transfer switch in building 29 has drain lines run directly over the top of the switch as pictured to the right. No protective covers have been installed to prevent water from getting into the electrical

11 | P a g e equipment Such protection is required by National Fire Protection Association (NFPA), National Electrical Manufacturer’s Association (NEMA) guidelines and both National Electric Code section 110.26(F)(1)(a)-(d) outlined below.

Additionally, the building 67 main switchboard has sprinkler heads and related water pipes directly over or within the spray pattern of the electrical equipment as represented by the picture to the right. No protective covers have been installed to prevent water from getting into the electrical equipment nor are physical protective devices installed to protect the actual sprinkler heads from physical damage.

110.26(F)(1)(a) through 110.26(F)(1)(d)

(F) Dedicated Equipment Space. All switchboards, panelboards, distribution boards, and motor control centers shall be located in dedicated spaces and protected from damage.

Exception: Control equipment that by its very nature or because of other rules of the Code must be adjacent to or within sight of its operating machinery shall be permitted in those locations.

(1) Indoor. Indoor installations shall comply with 110.26(F)(1)(a) through (F)(1)(d).

(a) Dedicated Electrical Space. The space equal to the width and depth of the equipment and extending from the floor to a height of 1.8 m (6 ft) above the equipment or to the structural ceiling, whichever is lower, shall be dedicated to the electrical installation. No piping, ducts, leak protection apparatus, or other equipment foreign to the electrical installation shall be located in this zone.

Exception: Suspended ceilings with removable panels shall be permitted within the 1.8-m (6-ft) zone.

(b) Foreign Systems. The area above the dedicated space required by 110.26(F)(1)(a) shall be permitted to contain foreign systems, provided protection is installed to avoid damage to the electrical equipment from condensation, leaks, or breaks in such foreign systems.

(c) Sprinkler Protection. Sprinkler protection shall be permitted for the dedicated space where the piping complies with this section.

(d) Suspended Ceilings. A dropped, suspended, or similar ceiling that does not add strength to the building structure shall not be considered a structural ceiling.

The dedicated electrical space includes the space defined by extending the footprint of the switchboard or panelboard from the floor to a height of 6 ft above the height of the equipment or to the structural ceiling, whichever is lower. This reserved space permits busways, conduits, raceways, and cables to enter the equipment. The dedicated electrical space must be clear of piping, ducts, leak protection apparatus, or equipment foreign to the electrical installation. Plumbing, heating, ventilation, and air-conditioning piping, ducts, and equipment must be installed outside the width and depth zone.

Foreign systems installed directly above the dedicated space reserved for electrical equipment must include protective equipment that ensures that occurrences such as leaks, condensation, and even breaks do not damage the electrical equipment located below.

Sprinkler protection is permitted for the dedicated spaces as long as the sprinkler or other suppression system piping complies with 110.26(F)(1)(c). A dropped, suspended, or similar ceiling is permitted to be located directly in the dedicated space, as are building structural members.

Exhibits 110.21, 110.22, and 110.23 illustrate the two distinct indoor installation spaces required by 110.26(A) and 110.26(F), that is, the working space and the dedicated electrical space.

In Exhibit 110.21, the dedicated electrical space required by 110.26(F) is the space outlined by the width and the depth of the equipment (the footprint) and extending from the floor to 6 ft above the equipment or to the structural ceiling (whichever is lower). The dedicated electrical space is reserved for the installation of electrical equipment and for the installation of conduits, cable trays, and so on, entering or exiting that equipment. The outlined area in front of the electrical equipment in Exhibit 110.21 is the working space

12 | P a g e required by 110.26(A). Note that sprinkler protection is afforded the entire dedicated electrical space and working space without actually entering either space. Also note that the exhaust duct is not located in or directly above the dedicated electrical space. Although not specifically required to be located here, this duct location may be a cost-effective solution that avoids the substantial physical protection requirements of 110.26(F)(1)(b).

Exhibit 110.21 The two distinct indoor installation spaces required by 110.26(A) and 110.26(F): the working space and the dedicated electrical space.

Shields need to be installed over the transfer switch to prevent damage from overhead water sources (drain lines) from penetrating the enclosures. Such penetration could lead to a potentially catastrophic failure.

A project should be initiated to install protective covers over the main switchboard in building 67 as well as cages over the sprinkler heads.

10. Defective Circuit Breakers

Beyond conditions already noted, one additional circuit breaker was found to be defective.

The circuit 2 breaker in panel 2LP8 (building 2) would not reset after exercising.

The circuit 2 breaker in panel 2LP8 should be replaced.

13 | P a g e

11. Circuit Identification

Numerous switchboards and panels throughout the facility were found be missing or have incomplete circuit directories. In some cases, circuits have multiple identifications where the circuits have changed over the years as represented by the picture to the right. It is unclear which label is correct. This condition can be dangerous for personnel attempting to isolate a circuit for maintenance. Circuit markings are required by National Electric Code section 110.22(A) outlined below.

110.22(A) Circuit Identification

Each disconnecting means shall be legibly marked to indicate its purpose unless located and arranged so the purpose is evident. The marking shall be of sufficient durability to withstand the environment involved.

A project needs to be initiated to create or update all circuit directories and remove old circuit labels throughout the facility.

It is further recommended an electronic version of each directory be created – Microsoft Excel is a good platform for this purpose. Future circuit changes can be readily updated in the program and new panel directories created on the fly and placed inside the panels ensuring directories are properly maintained.

12. “Clip-On” Circuit Breakers

Three (3) panels were found to contain “clip-on” style circuit breakers. Those panels are:

▪ Building 4 – Panel 74LP1

▪ Building 46 – Panel 46LP2

▪ Building 48 – Panel 48LP1

This style breaker has a tendency for the bus side clips to lose their tension leading to overheating with the possibility of fire. It should be noted there is no means of tightening these connections when they loosen. The pictures below are representative of the breaker style and overheating developing from the clips losing their tension.

14 | P a g e

It should be noted “clip-on” style circuit breakers are not allowed in GSA facilities per GSA PBS P100 standards. Section 6.10 on page 132 of this standard outlined below details the requirement for panelboards where branch circuit breakers to be of the “bolt-on” style.

GSA PSB P100 Reference

6.10 Panelboards

Branch circuit breakers must be bolt-on designed for replacement without disturbing the adjacent units. Breakers must comply with the requirements of UL 489, thermal magnetic type with a short-circuit rating greater than the calculated available fault current. Panels must be specified with “door-in-door” trim.

These three (3) panels need to be replaced with those containing “bolt-on” style breakers.

Future installations should specify “bolt-on” style breaker panels.

3. 4-Hour ESS

The 4-hour ESS Test was performed on December 5, 2020 in accordance with guidelines established by NFPA 110 and VHA Directive 1028. Below is the timeline for completion of this phase of the project:

a) Outage was initiated at 9:28 Am with Kentucky Utilities (KU) turning power off to the facility.

b) All generators were reported as starting properly and all transfer switches transferred to the emergency position.

c) No reports of equipment problems were reported by VAMC personnel.

d) Slocum and Associates had technicians standing by to help with any equipment problems. No problems were reported by VA personnel.

e) After one hour of the facility being on emergency power only, VA personnel had not requested assistance nor were any equipment problems reported by VA personnel.

f) After two hours of the facility being on emergency power only, VA personnel had not requested assistance nor were any equipment problems reported by VA personnel.

g) After three hours of the facility being on emergency power only, VA personnel had not requested assistance nor were any equipment problems reported by VA personnel.

h) After four hours of the facility being on emergency power only, VA personnel had not requested assistance nor were any equipment problems reported by VA personnel.

i) At this time, 1:28 PM, the 4-hour requirement had been met. However, utility power was not restored to the facility due to continued testing by Slocum personnel.

Additionally, KU had an equipment problem requiring supplemental resources to resolve.

21.9

39.3 °C

15 | P a g e

j) At approximately 3 Pm, all power was restored to the facility.

k) All transfer switches transferred back to normal power and all generators went through normal cool down and shutdown.

l) During the entire utility outage, no problems were reported by VA personnel and no requests for assistance were made of Slocum personnel.

13. Thermographic Issues

No thermal issues were noted during the infrared scan of this facility.

CD-ROM Version

Inside the front cover of each report copy is a CD-ROM containing an electronic copy of the Electrical Testing & Maintenance Report. These have been created using Adobe Acrobat and can be viewed by anyone with Adobe Acrobat Reader 7.0 or higher on their computer.

Additional report and work order copies can be printed using this CD-ROM.

In the event you do not have a compatible viewer, you can download a free version from the internet following the instructions at:

www.adobe.com/products/acrobat/index.html http://www.adobe.com/products/acrobat/index.html

Electrical Maintenance & Testing Project, Contract No. 36C24920P0633 VA Medical Center – Sousley Division – Lexington, Kentucky

Publications Cover

Enclosed are publications or articles referenced in this report. Such publications are invaluable and designed to provide additional discussion, authoritative commentary and/or guidance on issues noted during this testing session. Publication/articles have been broken down into categories and separated by a red divider page as follows:

Equipment Installation Guidelines

▪ “Renovating Electrical Distribution Systems,” article by Syed M Peeran, May 2009 issue of Consulting-Specifying Engineer (re-print)

▪ “Electrical Equipment and Components in Adverse/Corrosive Environments” by

Square D, September 2004

▪ “Harmonics in your electrical system” by Eaton Powerware, undated

Renovating electrical distribution systems

How to decide what to keep and what to discard in an electrical distribution system.

Syed M. Peeran, PhD, PE; Mario Vecchiarello, PE; and Jeff Romeo, PE

05/09/2011

Like death and taxes, failure of electrical distribution equipment is inevitable; it is only a matter of time before we need to deal with it. Upon installation, all electrical equipment begins to deteriorate due to absorption of moisture, daily temperature cycles, collection of dust, condensation, mechanical wear of circuit breaker contacts and contactors, weakening of operating springs, deterioration of insulating materials, rusting of switchgear enclosures, or drying out of capacitor dielectric.

Aging electrical components are potential hazards in any distribution system, particularly in modern automated and unattended systems. After the expected useful life, the failure of electrical equipment is unpredictable. Electrical equipment failures have been the most common cause of fires in buildings and facilities. Therefore, renovating electrical distribution systems is essential to deliver reliable power to the loads.

Aging of electrical equipment

Moisture and dust are sworn enemies of all electrical equipment. Many types of electrical equipment are installed outdoors or in unconditioned spaces where there is no control of temperature and humidity. Even in the case of equipment installed in weather-conditioned spaces, there is a gradual but definite deterioration. Eventually, the equipment will reach a condition in which its reliability becomes questionable.

All electrical equipment ages at different rates based upon the quality of equipment, maintenance, and its environment. This article will help the reader identify when the equipment has reached the end of its useful life. See Table 1 for some general life expectancies. While planning renovation of an electrical distribution system, a starting point would be to determine the ages of the various components of the system.

http://www.addthis.com/bookmark.php?v=250&pub=xa-4a8ac57416db70f7

Electrical insulation

The weakest and fastest degrading component of any electrical equipment is the insulation. In cables, transformers, reactors, trip coils of circuit breakers, operating coils of contactors, motors, and capacitors, solid synthetic and paper insulation is used. The degradation of this insulation depends greatly upon the maximum temperature to which it is subjected. Insulation is, therefore, classed according to the maximum temperature it can be exposed to. Table 2 shows the temperature rating of different classes of insulation used in electrical equipment.

A general rule of thumb is that the life of the insulation is halved for every 10 C rise in the operating temperature above the rated maximum temperature.

Capacitors

Several types of capacitors are in use in low-voltage (LV) and medium-voltage (MV) distribution systems, such as surge capacitors to protect motor windings, power factor correcting capacitors, commutating capacitors in variable frequency drives (VFDs), capacitors in active and passive filters, and pole-mounted capacitors in overhead distribution lines for voltage drop compensation. The most common application is for power factor correction in ratings up to several hundred kVAR. Three-phase and single-phase capacitors in hermetically sealed units are available in rectangular and cylindrical metal enclosures. The dielectric material used is metalized polypropylene film encapsulated in a thermal setting resin. Pressure-sensitive interrupters are provided to disconnect the capacitors in the event of an internal fault. Externally, the capacitors are invariably fused because the failure is generally due to short circuits.

There is a continuous power loss internally of approximately 0.5 W/kVAR due to dielectric hysteresis.

This loss causes internal heating and drying of the insulating resin resulting in a reduction of the kVAR compensation which goes undetected. Manufacturers state that the expected life is approximately

150,000 hours of continuous operation (approximately 17 years). Actually, the expected useful life at nameplate values is shorter than 17 years because capacitors are constantly exposed to system over-voltages and voltage transients. The operating environment is more severe than the shop testing environment.

Internal short-circuits in the polypropylene film can be detected by input current measurements.

Reduction in the kVAR compensation due to aging can also be detected by current measurement using a clamp-on ammeter.

Liquid filled transformers

Liquid filled transformers are typically installed outdoors in weatherproof enclosures on concrete pads

(pad-mounted transformers) or on poles. The liquid serves the dual purpose of cooling the transformer coils by convection and providing insulation between the coils and the grounded tank. Modern transformers use stable silicon-based or fluorinated hydrocarbons or combustion-resistant vegetable oil-based dielectric fluids or synthetic esters. Older transformers used insulating mineral oils.

In the transformer, the insulating fluid degrades first. The degradation is due to ingress of moisture, corona (minute arcing at the windings generating gases that get dissolved in the fluid), loss of dielectric strength due to moisture content, impurities, and periodic heating and cooling. With regular maintenance, testing, and replacement of the fluid when necessary, the liquid-filled transformer can provide reliable service for more than 30 years.

LV molded case circuit breakers

Molded case circuit breakers are used widely in LV distribution systems. There are two components that wear out with use: the copper contacts and the spring-loaded operating mechanism. The contacts wear out due to abrasion while closing and arcing while opening the breaker. In large breakers, the contacts are replaceable.

With use, the operating mechanism becomes sluggish, resulting in delayed clearing times beyond that given in the manufacturer’s published curves. The springs generally retain their strength for the life of the breaker and beyond. The lubrication, however, becomes the limiting factor. Grease and red oil used in the lubrication deteriorate, resulting in the slower clearing times. As shown in Figure 2, the manufacturer’s published tripping curves are actually bands within which a good breaker is expected to operate.

A possible shifting of this band is due to aging. If the tests reveal that the breaker operation is much above the original tripping band, then it is time to replace the breaker.

Most manufacturers state that the expected useful life is 20 years. Beyond 20 years it would be prudent to replace all molded case breakers of 100 A and lower rating. For larger breakers, it may be worthwhile to perform tests to determine satisfactory operation and develop a replacement program.

LV and MV power circuit breakers

LV power circuit breakers are available in continuous current ratings of up to 6000 A at 600 V. MV circuit breakers are available for up to 35 kV rating. These breakers are most commonly the draw-out type. The current-carrying contacts separate in air and the arc is quenched by the de-Ion grid extinguisher. The moving contacts are pivoted. Operation of the breaker is by a charged spring, which is released by the trip coil. The trip coil is controlled by an electronic trip unit, which can provide adjustable time overcurrent and instantaneous overcurrent protection.

The current-carrying contacts consist of the main and the arcing contacts, the latter opening last when the breaker trips. The arcing contacts are easily replaceable. As in the molded case breakers, contact wear results from abrasion while closing and from pitting due to the arc while opening. The condition of the contacts can be determined by measuring the contact resistance with a micro-ohmmeter, when the breaker is drawn out. A 4000 A, 480 V breaker in good condition should have a contact resistance of less than 30 micro-Ohms. The condition of the contacts can also be checked by infrared photography.

The operating mechanism requires greater attention, adjustments, and maintenance. Excessive pressure between the contacts would cause bending and misalignment. Inadequate pressure would lead to minute arcing and heating. Lubrication of the moving parts is the key to successful consistent operation of the breaker. Most manufacturers use red oil for both the current-carrying parts and the operating mechanism. As the breaker ages, the oil dries out and flakes off. There will then be metal-to-metal sliding, which wears out the surfaces and can cause misalignment. Eventually the breaker will “seize,” resulting in a failure to open or taking several seconds to open. This could be the beginning of a catastrophic failure unless there is an upstream backup breaker to clear the faulted condition. It is, therefore, essential to check out the mechanism, lubricate it, and exercise it on a regular basis. As with transformers, the useful life of power circuit breakers can be extended with preventive maintenance and testing. As a result, power circuit breakers are not normally included in the list of equipment to be replaced during renovation unless test results suggest otherwise or the breakers are antiquated and replacement parts become difficult to procure.

MV vacuum circuit breakers

In vacuum circuit breakers, the current-carrying contacts are encased in vacuum bottles.

Theoretically, current interruption should take place within one cycle. Practically, however, it takes two to three cycles to interrupt the current. Because of the reduced arcing due to the vacuum, the current-carrying contacts of the vacuum breaker should last longer than those in the air-break power circuit breaker. Because there are no arcing contacts, the entire vacuum bottle needs replacement when the contacts wear out.

The operating mechanism is similar to that of the air-break power circuit breaker. As in the case of the air-break circuit breaker, lubrication of the operating mechanism constitutes a limiting factor.

Therefore, the life of the vacuum circuit breaker is approximately the same as that of an equivalent air-break power circuit breaker.

Dry-type transformers and reactors

Dry-type transformers are used widely to supply lighting loads and other LV single- and three-phase loads. Reactors are used for short-circuit current limiting in situations where the potential short-circuit current exceeds the rating of the existing equipment. Reactors are also used as chokes in tuned harmonic filters and in the dc links of older variable frequency drives. Generally, they are dry-type using vacuum pressure impregnated insulation.

The first sign of degradation of insulation appears as discoloration of the bright yellow insulation due to the heat produced in the coils. The insulation becomes brittle and cracks, permitting ingress of moisture when it cools, which leads to further deterioration.

Eventually, failure occurs as short-circuits between the winding turns. The expected life of dry-type transformers and reactors is approximately 25 to 30 years. There are no known methods of determining the remaining life of an old transformer or a reactor. Therefore, the industry’s practice is to replace the equipment only after it equipment fails. While renovations are planned, these two types of equipment should not be included in the list of equipment to be replaced unless they are older than

30 years.

LV and MV cables

To a layman, what could be simpler than an electrical cable? It is a stranded aluminum or copper conductor wrapped with insulation and a weather-resistance jacket to give mechanical strength. Yet, manufacturing electrical power and control cables is a highly specialized industry. The assessment of a cable’s electrical integrity and the estimation of its remaining life are highly complex. A cable is a piece of equipment whose electrical integrity degrades rapidly and progressively while in service primarily due to the development of air and gas pockets or voids inside the insulation due to thermal expansion and contraction. The voids are the areas of high dielectric stress, which causes partial discharges

(minute arcing inside the void) that further degrade the insulation. Cable insulation degradation may be accelerated if the cables are immersed in water. Water submergence may produce water treeing within the cable’s insulation, which could result in insulation failure. It is a common occurrence for cables installed within underground duct banks to become submerged.

Measurements of the mechanical properties such as the jacket material hardness and loss of elongation retention do not indicate electrical insulation integrity. Electrical integrity of the cable is tested by Hipot tests and insulation resistance tests. Estimation of the remaining life of the cable based upon these measurements is questionable. The best conclusion that can be drawn is that, if the results are satisfactory, the cable is acceptable with no guarantee of future satisfactory performance.

Internal void formation is an indication of the degradation of the cable. The voids contain air or gases that are ionized. The void size increases due to the ionization. Therefore, the sizes of the voids indicate the age of the cable. One technique to determine the void size is acoustic spectroscopy. As the number and size of voids increase, the effective thickness of insulation to withstand the voltage decreases. The limit of equivalent thickness of insulation that is just enough to prevent failure is determined for each type of insulation by separate test. Using this information and the information about the number and size of the voids, the remaining life of the cable can be accurately predicted.

Electromagnetic protective relays

Older protective relays to provide overcurrent, overvoltage, reverse power, and other protective functions used the induction disk, induction cylinder, or beam-type construction. They depend upon a delicately balanced aluminum disk, aluminum cylinder, or a beam for their respective successful operation. (Because of this, they are generally unable to ride through seismic events.) Settings are adjustable by taps in the operating coil, the position of a braking magnet and length of travel of the moving contacts to meet the fixed contacts.

Most of the time, the relays are inactive. They are activated only when there is a fault. The useful life of the relay depends upon the number of times it is called upon to operate. The useful life of the electromagnetic relay is approximately 30 years. However, these relays are rapidly giving way to more versatile and infinitely adjustable microprocessor-based electronic relays. Electronic relays are more reliable than electromagnetic relays and can meet seismic withstand requirements. In addition, the need to be compatible with modern supervisory control and data acquisition systems at the facility has essentially made the electromagnetic relays obsolete. Therefore, when renovation is planned, the list of equipment to be replaced should include electromagnetic protective relays.

VFDs and UPSs

VFDs and uninterruptible power supplies (UPSs) are complex assemblies of several components such as power electronic devices, capacitors, inductors, integrated electronic circuits, and microprocessors, which have different aging characteristics. Theoretically, the useful life of the VFD is the least of the useful lives of the various components. Practically, however, the individual major components are modularized and can be replaced at fraction of the cost of a new VFD. Therefore, the useful life of the

VFD is determined by the useful life of the components that cannot be replaced.

In the past 40 years, VFD technology has advanced considerably. Older VFDs used silicon diodes, thyristors, and gate turn-off thyristors as the power…