Bowling VA Electrical Maintenance and Testing Report.pdf

Electrical Maintenance & Testing ProjectElectrical Maintenance & Testing Project

CoverCover

Submitted by

Veterans Affairs Medical Center Bowling Division

Lexington, Kentucky

Contract No. VA36C24920P0633

Contracting Officer: Michael Brown

Phone No: (615)225-5975

Jerry M. Parks Jr., Project Manager

Project Test Report

March 6-13, 2021

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 – Bowling Division

Lexington, Kentucky March 6-13, 2021

Section 1 Electrical Testing and Maintenance Summary

Section 2 Publications/Exhibits

Section 3 Electrical Test Records

Section 4 Individual Thermographic Report

Section 5 Specialized Tools & Equipment, Testing Specifications and Licenses/Certifications (Digital Version Only)

Table of Contents

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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 – Bowling Division in Lexington, Kentucky on March 6-13, 2021 under contract number 36C24920P0633. All services were conducted in accordance with contract specifications, industry standards, NFPA 70B and manufacturer’s recommendations.

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 Individual Thermographic Test Records

Section 5 Licenses, Certificates, Specialized Tools & Equipment

The types of equipment tested during this testing session included:

Medium Voltage Circuit Breakers

Medium Voltage Switches

Medium Voltage Network Protectors

Medium Voltage Oil- and Dry-Type Transformers

Low Voltage Switchboards and Circuit Breakers (select areas)

Automatic Transfer Switches

Motor Control Centers

Electrical Panels

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

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.

Slocum & Associates in cooperation with

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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 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?

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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?

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/Recommendations

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.

a) The Tower Building medium voltage system is in poor overall condition and technically obsolete.

i. The GE Magna-Blast breakers are approximately 50 years of age, technically obsolete and in poor condition. The existing battery system is defective as it does not generate sufficient power supply to enable the breakers to be lowered and raised for testing and maintenance purposes.

ii. The GE medium voltage air switches are of the same age as the Magna-Blast breakers above. More importantly, they contain floating contacts that have a history of breaking. Replacement parts are no longer available. Failure of these contacts would render the switches inoperable resulting in a loss of normal power to all downstream circuits. An emergency replacement would be very lengthy and require the facility to operate on emergency power during this time. Note that normal power circuits would be completely down for the duration of the replacement.

iii. The network protectors provide no functionality as there are not multiple sources of power to the Tower Building by which they could switch in the event of a power loss to one of the incoming feeds. These should not be included in any future substation designs.

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iv. The protective relaying systems in both the medium voltage substation and low voltage switchboards are also roughly 50 years of age and are original electro-mechanical relays.

These conditions create great concern regarding the reliability and ability to safely protect the electrical system and its occupants in this segment of the facility. These equipment items should be rated as an “F” using the VA’s Facility Condition Assessment guidelines. These systems need to be replaced with the type of equipment contained in substations in the recently-installed Square D Substations 2A and 2B in the Chiller Plant – vacuum circuit breakers, oil or dry-type transformers, solid-state relaying, etc.

In relation to the Tower Building low voltage switchboards, with rare exception, the trip units are roughly 40 years of age and proper operation is unpredictable. They are technically obsolete and reliability is unpredictable. These equipment items should be rated as a “D” using the VA’s Facility Condition Assessment guidelines. These trip units should be upgraded to the latest solid state trip units to provide a reliable system. The breakers themselves should be reconditioned as part of the trip unit upgrade as they are well built and very functional. That would save a significant amount of money in created a reliable electrical system. The new trip units could include ground fault protection and eliminate the need for the existing obsolete ground fault relays.

b) Chiller Plant Substation 1A and 1B is an original Siemens-Allis substation comparable in age to the substations in the Tower Building carrying the same technical obsolescence and reliability issues. During the recent testing session, these breakers failed to operate mechanically even though they have been serviced at regular intervals. This raises the question of their ability to respond to or operate in the event of a fault. Faults could escalate upstream taking out larger segments of the facility with the potential for a fire in the event the fault doesn’t clear.

These equipment items should be rated as an “F” using the VA’s Facility Condition Assessment guidelines. These two substations should be replaced as soon as possible. The majority of the circuits in these substations are now spare with the installation of the new Square D Substations 2A and 2B. There is the potential to avoid direct replacement if this small amount of circuits could be incorporated into the open spaces within the new Square D substations. That would limit replacement adding required circuit breakers and relocating feeder conductors to the new cubicles.

c) The Main Hospital Low Voltage Switchboard #1 and #2 are of the same age as the Chiller Plant Substations 1A and 1B. These devices operated properly during the recent testing session. However, they contain the same obsolete trip units that are technically obsolete and are questionable in their response to a fault.

These equipment items should be rated as an “D” using the VA’s Facility Condition Assessment guidelines. The trip units should be upgraded to the latest solid state trip units to provide a reliable system. The breakers themselves should be reconditioned as part of the trip unit upgrade as they are well built and very functional.

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d) The Main Hospital generator and emergency switchboards are exposed outside air due to louvres exposing these switchboards to abnormal ambient temperature and dirt/debris. Such conditions are leading to corrosion of the equipment and penetration of the dirt/debris into the switchboards and circuit breakers. This can affect the proper operation of the circuit breakers and can lead to either a delayed or failure to respond to a fault. Abnormal temperatures combined with dirt/debris can lead the breakers to either open slowly or not at all in response to a fault with the potential for a catastrophic failure. This can lead to a significant arc flash incident and even fire.

These equipment items should be rated as an “D” using the VA’s Facility Condition Assessment guidelines.

The generator and emergency switchboards should be replaced as soon as possible to provide safe and reliable power to the emergency circuits of the Main Hospital.

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 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.

2. Overhead Sprinklers

Issue

Much of the electrical equipment located throughout this facility 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. Additionally, no protective covers have been installed to prevent water from

6 | P a g e getting into the electrical equipment nor are physical protective devices installed to protect the actual sprinkler heads from physical damage. Both are required by National Electric Code section 110.26(F)(1)(a) through (F)(1)(d) as outlined below.

NEC Reference

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.

The electrical equipment also must be protected from physical damage. Damage can be caused by activities performed near the equipment, such as material handling by personnel or the operation of a forklift or other mobile equipment. See 110.27(B) for other provisions relating to the protection of electrical equipment.

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 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

7 | P a g e 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.

Recommendation

A facility-wide survey of all electrical rooms/closets in this facility should be conducted to identify electrical components not properly protected or shielded from the sprinkler systems spray patterns or with overhead water lines. Additionally, the survey needs to identify sprinkler heads without physical protective covers.

Shields need to be installed in all areas where electrical components are within the spray pattern or have overhead water lines to prevent damage to prevent overhead water sources (sprinklers and water lines) from penetrating the enclosures. Such penetration could lead to a potentially catastrophic failure. Protective covers or cages need to be installed on unprotected sprinkler heads to prevent accidental activation with the same potential for catastrophic failure as mentioned above.

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3. Improper Working Clearance

Switchboards HSB1 and HSB2 in the Chiller Plant have 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.

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.

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.

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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.

Switchboards HSB1 and HSB2 in the Chiller Plant need 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.

4. Common Point of Failure

Switchboards SBC and SBE in the Tower Building have automatic transfer switches (ATS) on the front end of these two systems providing both normal and emergency power to these switchboards. This creates a “common point of failure” as a failure of any of the breakers in these switchboards will result in a total power loss to downstream circuits. In the event the Main circuit breaker fails, the entire switchboard will be without power. Additionally, spare circuit breakers are typically not available for these larger circuit breakers.

Due to the age of these two switchboards, the present configuration should not be changed.

However, both switchboards SBC and SBE should be replaced in the near future as mentioned earlier in this Summary. Consideration should be given to implementing smaller ATS’ as close to the desired load as possible. This will create a redundancy down to the circuit feeding the ATS. Feeder breakers at the lower levels of the electrical system are typically smaller, replacements more readily available and are cheaper to replace or have spare circuit breakers on hand.

5. Circuit Directories/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 creating confusion as to which is the correct circuit.

Many new equipment installations were found without any circuit markings.

There are multiple panels with the same circuit ID. As an example, there are two or more panels labeled CLF and CPM in the Tower Building.

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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.

Furthermore, none of the emergency equipment in this facility is properly designated as emergency equipment as required by National Electric Code section700.9 referenced below.

700.9 Wiring, Emergency System.

(A) Identification. All boxes and enclosures (including transfer switches, generators, and power panels) for emergency circuits shall be permanently marked so they will be readily identified as a component of an emergency circuit or system.

A project needs to be initiated to perform the following:

a. Develop a circuit identification system for labeling electrical panels.

Consideration should be given to developing a system that creates some descriptive features to help locate a panel simply using the circuit id. Below is an example of such a system:

Panel ID: 1ALXXX

1 – provides the floor level.

A – indicates the hospital wing L – N for normal, L for life safety, C for critical and E for equipment XXX – a unique number or characters for each panel

b. Labels for emergency sourced panels need to be readily identifiable as being part of the emergency system. It is recommended these panel labels be done with white lettering on a red label to meet this requirement.

c. Replace existing panel id labels with the newly created circuit id labels. It would be highly beneficial to provide the power source and location on these labels.

This would enhance lockout/tagout procedures and reduce troubleshooting efforts typically slowed by attempting to locate the upstream power source for isolation purposes.

d. Create or update all circuit directories and remove old circuit labels throughout the facility. If this is done by VA personnel, consideration should be given to purchasing a 42-circuit tracing kit readily available for purchase for around $1,200. Such a kit substantially reduces the manhours required to trace circuits versus the effort required when utilizing a single circuit tracer.

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e. All electrical single-line drawings should be updated to incorporate the new circuit id labels along with all upgrades and additions to the electrical system.

This is necessary to provide maintenance personnel with up-to-date information to ensure proper safeguards are in place while performing maintenance operations.

f. Lockout/tagout procedures should be revised upon completion of the drawing updates. Both are necessary to provide maintenance personnel with up-to-date information to ensure proper safeguards are in place while performing maintenance operations.

g. New equipment installations need to be closely monitored to ensure the installing contractor provides circuit directories and equipment labels. These labels should be consistent with the circuit id system referenced in step a above.

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 with the exception of transformer T6.

Transformer T6 had abnormal carbon monoxide (CO2) and total dissolved combustible gas (TDCG) test results. These results indicate the possibility the paper insulation in the transformer is deteriorating. The extent of deterioration is not readily identifiable especially when previous oil test results are not available. Deterioration can lead to a transformer failure with a total loss of normal power to downstream circuits. This segment of the facility would be forced to operate on emergency power until a replacement could be installed.

Complete laboratory test results have been incorporated into the test records for the medium-voltage transformers located in tab 3 to this report. The “Transformer Oil Testing:

An Early Warning System That Works” by Robert Turcotte has been included in the Publication section located in tab 2 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.

It is recommended the oil in transformer T6 be sampled in six months with dissolved gas analysis (DGA) testing performed. CO2 and TDCG results should be compared with those from this testing session to help determine if the levels are steady or increasing. Any further action would be based on comparative test results.

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7. Variable Frequency Drives (VFD)

This facility contains 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.

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 will experience 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

d. Install K-type transformers capable of handling harmonic loads.

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8. Lack of Bus Duct Burms

The floor openings for the bus risers in this facility do not have 4” curbs around the base of the bus risers to prevent liquids from penetrating the bus as represented by the picture to the right. This creates the potential for liquids to penetrate the bus with the potential for a catastrophic failure if left uncorrected. Such requirements are outlined in National Electric Code section 368.10(c)(2) and NEMA Standard Publication BU 1.1-2005 outlined below (complete publication has been included in the Publications section located in section 2 of this report).

368.10(c)(2) Installation Through Floors

(b) In other than industrial establishments, where a vertical riser penetrates two or more dry floors, a minimum 100-mm (4-in.) high curb shall be installed around all floor openings for riser busways to prevent liquids from entering the opening. The curb shall be installed within 300 mm (12 in.) of the floor opening. Electrical equipment shall be located so that it will not be damaged by liquids that are retained by the curb.

NEMA Reference

6.8.2.2 Floor Level Liquids.

6.8.2.2 Floor level liquids—Four-inch minimum curbs should be installed around all floor openings for riser busways to prevent floor level liquids from entering the opening.

Initiate a project to install 4” curbs around the base of every bus riser floor opening. While concrete burms are ideal, a comparable result can be achieved through metal fabricated burms combined with a silicone caulk to seal the base area.

9. Lack of Disconnect Means

The higher bus plugs in the electrical closets do not have any means of disconnecting power from the floor. National Electric Code section 404.8, outlined below, requires a disconnect means to be operable from the floor or within 6’ 7” of the floor. The ladders placed in the majority of the electrical closets do not satisfy this code requirement.

404.8 Accessibility and Grouping.

(A) Location. All switches and circuit breakers used as switches shall be located so that they may be operated from a readily accessible place. They shall be installed such that the center of the grip of the operating handle of the switch or circuit breaker, when in its highest position, is not more than 2.0 m (6 ft 7 in.) above the floor or working platform.

Exception No. 1: On busway installations, fused switches and circuit breakers shall be permitted to be located at the same level as the busway. Suitable means shall be provided to operate the handle of the device from the floor.

Exception No. 2: Switches and circuit breakers installed adjacent to motors, appliances, or other equipment that they supply shall be permitted to be located higher than 2.0 m (6 ft 7 in.) and to be accessible by portable means.

Exception No. 3: Hookstick operable isolating switches shall be permitted at greater heights.

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Additionally, the secondary side disconnect switch for panel PP1C1 in room C127 (Emergency Room area) has been placed above the drop ceiling with no means of disconnect from the floor. Furthermore, access to this disconnect from a ladder is obstructed by a shelf in this room.

Recommendation

The higher bus plugs above 6’7” of the floor need to have some means by which to disconnect them from the floor to comply with NEC requirements.

Possible options are to connect rope/lanyards to both ends to the operating mechanism or place a “hookstick” (pictured to the right) or similar device in each of the electrical rooms for such purposes. Whatever approach is selected, it must be long enough, strong enough and capable of providing full opening and closing motions on the bus plugs.

The PP1C1 disconnect switch needs to have some form of disconnect from the ground or needs to be relocated.

10. Tower Medium Voltage Battery System

The battery system for the GE Magna-Blast medium voltage circuit breakers in the Tower Building is designed to power circuits for lowering and raising the breakers in their cubicles. This system was found to be in poor condition (as pictured to the right) with a system charge insufficient for the breakers to be lowered from their cubicle for testing and servicing.

Until this medium voltage system is replaced, the battery system needs to be properly maintained to allow these breakers to be serviced. This may require initial replacement of the existing battery system.

11. Thermographic Issues

Issues

Three (3) thermal issues were noted during the infrared scan due to loose connections.

Each issue and related recommendation is summarized in Attachment A following this summary and is fully reported on in tab 4 to this report.

Recommendations

Defective or loose connections need to be inspected and tightened per manufacturer’s recommendations.

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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

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Attachment A. Thermographic Report Summary

▪ Main Hospital, Rm. CM408, MCC4E – Medical Vac Duplex Unit appears to have a defective terminal crimp or loose ”A” phase secondary connection.

▪ Main Hospital, Rm. CM408, MCC4E – Medical Vac Duplex Unit T1 line side connection appears to be loose.

▪ Tower Bldg., Penthouse, MCE - EF-40 A/C-6 starter appears to have a loose T2 terminal connection.

▪ Main Hospital, Rm. CM408, MCC4E – Medical-Vac Duplex Unit starter needs to be de-energized. The ”A” phase secondary termination needs to be checked for a defective crimp.

Repair as needed. Tighten all connections per manufacturer’s recommendations.

▪ Main Hospital, Rm. CM408, MCC4E – Medical-Vac Duplex Unit starter needs to be de-energized. The T1 line side connection needs to be tightened per per manufacturer’s recommendations.

▪ Tower Bldg., Penthouse, MCE - EF-40 A/C-6 starter needs to be de-energized. The T2 connection needs to be tightened per per manufacturer’s recommendations.

31.3

53.0 °C

31.6

73.7 °C

24.8

56.8 °C

Electrical Maintenance & Testing Project, Contract No. 36C24920P0633 VA Medical Center – Bowling 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)

▪ “Transformer Oil Testing: An Early Warning System That Works,” article by Robert

Turcotte, Electrical Loss Control, June 2, 2008. (re-print)

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

▪ General Instructions for Handling, Installation, Operation and Maintenance of Busway Rate 600 Volts or Less, NEMA Standards Publication BU 1.1-2005

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.

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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.