ML15341A328

Part 21 Report Regarding Improper Silver Plating During Refurbishment of AK-25 Type Circuit Breakers, Per Fort Calhoun, Unit 1

ML15341A328
Person / Time
Site:	Fort Calhoun
Issue date:	12/01/2015
From:	Hale R United Controls International
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML15341A328 (13)

Text

12/01/2015 U.,g. Nuclear R+*ulat+rv (*,mmiceinn #')nDPatl,. f'o.*,* I*'*,,*e.e JPTn,* I Part 21 (PAR) Event# 51574 Rep Org: UNITED CONTROLS INTERNATIONAL Notification Date I Time: 12/01/2015 14:53 (EST)

Supplier: UNITED CONTROLS INTERNATIONAL Event Date I Time: 10/12/2015 (EST)

Last Modification: 12/01/2015 Region: 1 Docket #:

City: NORCROSS Agreement State: Yes County: License #:

State: GA NRC Notified by: ROB HALE Notifications: OMAR LOPEZ R20O HQ Ops Officer: DONALD NORWOOD HEATHER GEPEORD R4DO Emergency Class: NON EMERGENCY PART 2 1/50.55 REACTORS EMAIL 10 CFR Section:

21.21(d)(3)(i) DEFECTS AND NONCOMPLIANCE PART 21 REPORT - IMPROPER SILVER PLATING DURING REFUBISHMENT OF AK-25 TYPE CIRCUIT BREAKERS The following information is a synopsis of information received via E-mail:

During refurbishment of General Electric AK-25 type circuit breakers (P/N's: AK-2A-25-1, AK-3A-25-1, and AK-7A-25-1) by United Controls International (UCI), non-currentcarrying/non-copper based components of the upper stud assembly were silver plated. Bubbling of the silver plating was later noted which is an indication that the plating material was not adhering to the base metal. Flaking of the silver plating material may occur and may introduce conductive foreign material into the host circuit breaker. Introduction of this conductive material could create the possibility of a short circuit of the current sensor terminal board for circuit breakers configured with RMS-9 trip units and subsequent failure of the circuit breaker.

Fort Calhoun Nuclear Station is the only known recipient of affected breakers. Fort Calhoun received 18 breakers that contained improperly silver plated components. 14 of these 18 circuit breakers have been returned to UCI.

Four of the 18 circuit breakers have been installed at Fort Calhoun and UCI is currently awaiting the return of these four circuit breakers.

UC FAX TRAN SMITTAL DATE: December 1,2015 TO: NRC OPERATIONS FROM: Korina Looft/UCI CENTER FAX: 301-816-5151 FAX: 770-496-1422 TEL: 301-816-5100 TEL: 770-496-1406 Cc: Part 21 Notification PAGES: 12 pages with cover page COMMENTS:

I WILL FOLLOW UP AS DIRECTED TO MAKE SURE THE FAX TRANSMITTAL WAS RECEIVED.

THANK YOU, KORINA LOOFT

m !

... I - ". .

UNITED CONTROLS INTERNATIONAL December 1, 2015 U.S. Nuclear Regulatory Commission Document Control Desk Washington D.C. 20555-0001l

Subject:

10CFR Part 21 Notification of AK-25 Type Circuit Breakers P/N: AK-2A-25-1, AK-3A-25-1 and AK-7A-25-1 with Amptector or RMS-9 Trip Units Refurbished by United Controls International (UCI)

The purpose of this letter is to provide the NRC with a report in general conformity of the requirements of I0CFR Part 21.21.

On October 12, 2015 Omaha Public Power District (OPPD) - Fort Calhoun Nuclear Station notified UCI that the silver plating on the arc runner components of the circuit breaker with UCI serial number 006943-07-00001 was not smooth with small bubbles (reference Figures 1 thr'u 4).

The formation of bubbles in the plating material is an indication that the plating material was not properly adhering to the base metal. Failure of the plating material to properly adhere may result in the introduction of conductive foreign material inside the circuit breaker.

General Electric part number 269C283G2 upper stud assemblies (reference Figures 7 thru 11) are installed on each phase of the General Electric AK-25 type circuit breakers and the assemblies consist of the following components: arc runner (zinc plated carbon steel), lower bracket (zinc plated carbon steel), stud (silver plated copper), spacer (molybdenmm), pin (molybdenum), and rivets (brass). The assembly provides a current path from the upper primary disconnect finger assemblies to the stationary contacts. The primary disconnect finger assemblies are mounted on the stud component at the end thrtough-hole. The pin component holds the stationary contacts in place and prevents forward movement of the contacts. The arc runner component helps to secure the circuit breaker arc quenchers and direct arcing cun'ent upwards into the arc quenchers.

During refurbishment at UCI the silver plating of the current carrying/copper based components were inspected for complete coverage on the components. The tupper stud was a current carrying/copper based component that was identified as requirng additional silver plating during inspection. At the time of plating, the UCI inspector was unaware that the-upper stud component was permanently affixed to the upper stud assembly by rivets and that the upper stud assembly consisted of the materials identified above. During silver plating of the upper stud component the entire upper stud assembly was inadvertently plated with silver. After identification of the upper stud assembly components and the materials of the components it has become evident that silver plate does not adhere well to the materials of the non-current carrying components of the upper stud assembly and the bubbles formed in the plating material are attributed to the chemical reaction occurring between the original zinc plating and the new silver plating.

Page 1 ofl11

UNITED CONTROLS INTERNATIONAL In response to the finding presented above, UCI has recalled all circuit breakers in which the subject upper stud assemblies were plated with silver during refiurbishment on October 14, 2015 for inspection and evaluation. Currently four circuit breakers affected by this issue are installed at the customer site and UCI is awaiting return of these items. The circuit breakers affected by this issue were supplied to OPPD under purchase orders 00217277, 00217497, 00217657, and 00208727. UCI is currently evaluating methods of removing the silver plating from the non-current carrying components of the uipper stud assembly or replacing the incorrectly plated items.

As a preventative measure, UCI is evaluating methods for plating of only the upper stud component. UCI has implemented additional inspection criteria during the refurbishment process to avoid silver plating of non-current can'ying components.

The cause for concern in plating of silver on the non-current carrying/non-copper based components is the risk of plating *adhesion failure and possible introduction of conductive foreign material into the host circuit breaker. The introduction of foreign conductive material would pose the risk of short circuiting of exposed electrical connections or binding of moving components.

UCI has observed flaking and bubbling plating material on the subject silver plated non-current carrying components during inspection of the recalled circuit breakers. Examples of the bubbling and tlaking observed are presented in Figures 1 thru 6. The chemical reaction that occurs when silver is plated on the originally zinc plated components is considered to have occurred within the roughly two month period between initial plating and current inspection. The occurrence of bubbling plating material is not consistent throughout the plated items because the items were sand blasted prior to silver plating, to remove contaminants, which possibly removed the zinc plating from some areas on the item. The silver plating on the molybdenum components (pin and spacer) appears to have flaked off, likely due to abrasion from the stationary contacts.

Based on the amount of flaking and the size of the flakes observed, UCI considers the risk of short circuit or binding due to flaking conductive material to be a remote possibility based on the following. The components affected by the improper silver plating are enclosed within the arc quenchers of the circuit breaker and the only direction of propagation to other parts of the circuit breaker would be by falling out thr'ough the bottom of the arc quencher. Introduction of the conductive foreign material is considered to have no effect on the stationary and moveable contact functionality because the insulation surrounding these components does not allow contact with any other conducting material. Because the thickness of the silver plate is so thin (0.0001" to 0.0005"), if the flaking mnaterial were to make contact between the stationary and movable contacts during an opening event, it can be presumed that the foreign material would be vaporized due to the high curr'ent levels without any effect on the item's functionality. Note that due to the distance between the stationary and moveable contacts (approximately I", reference Figure 9) when the unit is in the open state, it is highly unlikely that a flake large enough to bridge this gap would occur and if such an event did occur the flake would most likely vaporize due to the thinness of the material. In addition, the likely-hood of binding occurring in the moveable or stationary contacts is not probable because the flaking material is so thin that the movement of either part would crumble the flakes.

Page 2 ofl1l

UNITED CONTROLS INTERNATIONAL If the flaking material were somehow able to fall through the arc quenchers and moveable contact areas, the insulation barriers present make it so that it is not possible for short circuiting of electrified component to the circuit breaker frame/ground. The only exposed electrified material that the flakes may come in contact with below the arc quenchers are identified as being the current transformer studs and terminal boards (RMvS-9 configuration only, reference Figures 12 thru 15), as well as the x-retay terminal block and x-relay coil terminal block (x-relay only installed on electrically operated circuit breakers, reference Figures 12, 16, 17).

The insulating barriers around the exposed current sensor studs and the spacing between adjacent current sensors make short-circuiting of the exposed conducting material improbable. The "

current transformer terminal boards pose the largest risk of short-circuiting because the insulating material and spacing between adjacent terminals is small; thus, introduction of conducting material between these terminals may cause interruption of operation of the connected x-relay. The x-relay terminal and coil connection have sufficient insulation barrier material and spacing to make short-circuiting improbable.

Based on the above evaluation, the improper plating of silver on the non-current carrying/copper based components of the upper stud assembly may represent a defective condition due to the possibility of short-circuit of the current sensor terminal board signals for circuit breakers configured for RMS-9 trip unit operation.

Required informnation as per 10OCFR Part 21.21 (d)(4) follows:

(i,) Name and Address of the individual or individuals informing the Commission Rob Hale President United Controls International 205 Scientific Drive Norcross, GA 30092 (ii) Identification of the facility, the activity, or the basic component supplied for sutch facility or such activity within the United States which fails to comply or contains a defect.

The items supplied to Omaha Public Power District - Fort Calhoun Nuclear Station were under purchase orders 00217277, 00217497, 00217657, and 00208727.

(iii) Identification of the firm constructing the facility or supplying the basic component which fails to comply or contains a defect.

United Controls International 205 Scientific Drive Norcross, GA 30092 Page 3 of 11

UNITED CONTROLS INTERNATIONAL (iv) Nature ofldhe defect or failure to comply and the safety hazard which is created or could be created by such defect or failure to comply.

Silver plating of the non-current carrying/non-copper based components on the upper stud assemblies of the AK-25 type circuit breaker may result in flaking of the silver plating material and may introduce conductive foreign material into the host circuit breaker.

Introduction of this conductive material creates the possibility of a short circuit between terminals of the current sensor terminal boards for circuit breakers configured with RMS-9 trip units. A short circuit of this terminal board may result in failure of the connected x-relay to operate as designed and subsequent failure of the circuit breaker.

(v) The date on which the information of such defect or failure to comply was obtained.

The silver plating issue was informted by Omaha Public Power District - Fort Calhoun Nuclear Station on October 12, 2015. On October 14, 2015 UCI initiated a recall of all items affected for inspection and evaluation.

(vi) in the case of a basic component which contains a defect or fails to comply, the number and location of these components in use at, supplied for, being supplied for, or may be supplied for, manufactured or being manufacturedfor one or more facilities or activities subject to the regulations in this Part.

Part Number Utility P~urchase Order Quantity AK-25 Type Circuit Omaha Public 00217277 2 Breaker Power District - 00217497 4 w/Amptector or Fort Calhoun 00217657 7 RMS-9 Trip Unit Station 00208727 5 Refurbished by UCI ______________

(vii) The corrective action which has been, is being, or will be taken; the name of the individual or organization responsible for the action; and the length of tinme that has beeni or will be taken to complete the action.

UCI is currently evaluating methods of removing the silver plating from the non-current carrying components of the upper stud assembly or replacing the incorrectly plated items. As a preventative measure, UCI is evaluating methods for plating of only the upper stud component. UCI has implemented additional inspection criteria during the refurbishment process to avoid silver plating of non-current carrying components.

Page 4 of 11

UNITED CON*TROLS INTERNATIONAL (viii) Any Advice related to thle defect or failure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasers or licensees.

This issue is isolated only to UCI refurbished items for a single customer. UCI advises that components requiring silver plating to be clearly defined prior to implementation.

(ix) In the case of an early site permnit, the entities to whom an early site permit was

- transferred.

Not Applicable.

If"you have any questions or wish to discuss this matter or this report, please contact:

Divya Paidy Engineering Manager dpaidy@unitedcontrols.com 770-496-1406 x 106 Sincerely, Rob Hale President United Controls International Page 5 ofi11

7 Figure

...... ... 1 (Arc Runner Front, Figure 2 (Arc Runner Back, Bubbling Exhibited) Bubbling Exhibited)

Figure 4 (Lower Bracket Back)

S Figure 3 (Lower Bracket Front)

Page 6 ofIlI

] Exhibited) Figure 6 (Pin. Flaking Exhibited)

Queches ArcQe Ar*.ece Figure 7 (Assembled Circuit Breaker) Figure 8 {Assembled Circuit Breaker)

Page 7 o f 11

SStationary Contacts]

in MvebleCotacts Figure 9 (Installed Upper Stud Assemblies. Arc Quenchers Removed & Not Silver Plated)

Figure 10 (Removed Upper Stud Assembly. Front)

Page 8 of 11

Upper Stud Figure l I (Removed Upper Stud Assembly, Side)

Current Sensors Current Sensor Terminal Boards

+ X-Relay Terminal & Coil Terminal Blocks (Not Visible. Behind)

Figure 12 (Assembled Circuit Breaker. Exposed Electrified Component Areas Located Below Arc Quenchers Noted)

Page 9 o f 11

{J I( ] I ( I I III

. ON [

A Senor z[Sud Figure 13 (Current Sensor Studs. Front)

T erminal Boards 1-igure 14t ('. urrent sensors 6: [ermineal Jzoarcls, tiottom)

Page 10 ofll

Figure 15 (Current Sensor Terminal Boards) igure 17 (X-Relay Coil Terminal Block)

Page 11 ofll

12/01/2015 U.,g. Nuclear R+*ulat+rv (*,mmiceinn #')nDPatl,. f'o.*,* I*'*,,*e.e JPTn,* I Part 21 (PAR) Event# 51574 Rep Org: UNITED CONTROLS INTERNATIONAL Notification Date I Time: 12/01/2015 14:53 (EST)

Supplier: UNITED CONTROLS INTERNATIONAL Event Date I Time: 10/12/2015 (EST)

Last Modification: 12/01/2015 Region: 1 Docket #:

City: NORCROSS Agreement State: Yes County: License #:

State: GA NRC Notified by: ROB HALE Notifications: OMAR LOPEZ R20O HQ Ops Officer: DONALD NORWOOD HEATHER GEPEORD R4DO Emergency Class: NON EMERGENCY PART 2 1/50.55 REACTORS EMAIL 10 CFR Section:

21.21(d)(3)(i) DEFECTS AND NONCOMPLIANCE PART 21 REPORT - IMPROPER SILVER PLATING DURING REFUBISHMENT OF AK-25 TYPE CIRCUIT BREAKERS The following information is a synopsis of information received via E-mail:

During refurbishment of General Electric AK-25 type circuit breakers (P/N's: AK-2A-25-1, AK-3A-25-1, and AK-7A-25-1) by United Controls International (UCI), non-currentcarrying/non-copper based components of the upper stud assembly were silver plated. Bubbling of the silver plating was later noted which is an indication that the plating material was not adhering to the base metal. Flaking of the silver plating material may occur and may introduce conductive foreign material into the host circuit breaker. Introduction of this conductive material could create the possibility of a short circuit of the current sensor terminal board for circuit breakers configured with RMS-9 trip units and subsequent failure of the circuit breaker.

Fort Calhoun Nuclear Station is the only known recipient of affected breakers. Fort Calhoun received 18 breakers that contained improperly silver plated components. 14 of these 18 circuit breakers have been returned to UCI.

Four of the 18 circuit breakers have been installed at Fort Calhoun and UCI is currently awaiting the return of these four circuit breakers.

UC FAX TRAN SMITTAL DATE: December 1,2015 TO: NRC OPERATIONS FROM: Korina Looft/UCI CENTER FAX: 301-816-5151 FAX: 770-496-1422 TEL: 301-816-5100 TEL: 770-496-1406 Cc: Part 21 Notification PAGES: 12 pages with cover page COMMENTS:

I WILL FOLLOW UP AS DIRECTED TO MAKE SURE THE FAX TRANSMITTAL WAS RECEIVED.

THANK YOU, KORINA LOOFT

m !

... I - ". .

UNITED CONTROLS INTERNATIONAL December 1, 2015 U.S. Nuclear Regulatory Commission Document Control Desk Washington D.C. 20555-0001l

Subject:

10CFR Part 21 Notification of AK-25 Type Circuit Breakers P/N: AK-2A-25-1, AK-3A-25-1 and AK-7A-25-1 with Amptector or RMS-9 Trip Units Refurbished by United Controls International (UCI)

The purpose of this letter is to provide the NRC with a report in general conformity of the requirements of I0CFR Part 21.21.

On October 12, 2015 Omaha Public Power District (OPPD) - Fort Calhoun Nuclear Station notified UCI that the silver plating on the arc runner components of the circuit breaker with UCI serial number 006943-07-00001 was not smooth with small bubbles (reference Figures 1 thr'u 4).

The formation of bubbles in the plating material is an indication that the plating material was not properly adhering to the base metal. Failure of the plating material to properly adhere may result in the introduction of conductive foreign material inside the circuit breaker.

General Electric part number 269C283G2 upper stud assemblies (reference Figures 7 thru 11) are installed on each phase of the General Electric AK-25 type circuit breakers and the assemblies consist of the following components: arc runner (zinc plated carbon steel), lower bracket (zinc plated carbon steel), stud (silver plated copper), spacer (molybdenmm), pin (molybdenum), and rivets (brass). The assembly provides a current path from the upper primary disconnect finger assemblies to the stationary contacts. The primary disconnect finger assemblies are mounted on the stud component at the end thrtough-hole. The pin component holds the stationary contacts in place and prevents forward movement of the contacts. The arc runner component helps to secure the circuit breaker arc quenchers and direct arcing cun'ent upwards into the arc quenchers.

During refurbishment at UCI the silver plating of the current carrying/copper based components were inspected for complete coverage on the components. The tupper stud was a current carrying/copper based component that was identified as requirng additional silver plating during inspection. At the time of plating, the UCI inspector was unaware that the-upper stud component was permanently affixed to the upper stud assembly by rivets and that the upper stud assembly consisted of the materials identified above. During silver plating of the upper stud component the entire upper stud assembly was inadvertently plated with silver. After identification of the upper stud assembly components and the materials of the components it has become evident that silver plate does not adhere well to the materials of the non-current carrying components of the upper stud assembly and the bubbles formed in the plating material are attributed to the chemical reaction occurring between the original zinc plating and the new silver plating.

Page 1 ofl11

UNITED CONTROLS INTERNATIONAL In response to the finding presented above, UCI has recalled all circuit breakers in which the subject upper stud assemblies were plated with silver during refiurbishment on October 14, 2015 for inspection and evaluation. Currently four circuit breakers affected by this issue are installed at the customer site and UCI is awaiting return of these items. The circuit breakers affected by this issue were supplied to OPPD under purchase orders 00217277, 00217497, 00217657, and 00208727. UCI is currently evaluating methods of removing the silver plating from the non-current carrying components of the uipper stud assembly or replacing the incorrectly plated items.

As a preventative measure, UCI is evaluating methods for plating of only the upper stud component. UCI has implemented additional inspection criteria during the refurbishment process to avoid silver plating of non-current can'ying components.

The cause for concern in plating of silver on the non-current carrying/non-copper based components is the risk of plating *adhesion failure and possible introduction of conductive foreign material into the host circuit breaker. The introduction of foreign conductive material would pose the risk of short circuiting of exposed electrical connections or binding of moving components.

UCI has observed flaking and bubbling plating material on the subject silver plated non-current carrying components during inspection of the recalled circuit breakers. Examples of the bubbling and tlaking observed are presented in Figures 1 thru 6. The chemical reaction that occurs when silver is plated on the originally zinc plated components is considered to have occurred within the roughly two month period between initial plating and current inspection. The occurrence of bubbling plating material is not consistent throughout the plated items because the items were sand blasted prior to silver plating, to remove contaminants, which possibly removed the zinc plating from some areas on the item. The silver plating on the molybdenum components (pin and spacer) appears to have flaked off, likely due to abrasion from the stationary contacts.

Based on the amount of flaking and the size of the flakes observed, UCI considers the risk of short circuit or binding due to flaking conductive material to be a remote possibility based on the following. The components affected by the improper silver plating are enclosed within the arc quenchers of the circuit breaker and the only direction of propagation to other parts of the circuit breaker would be by falling out thr'ough the bottom of the arc quencher. Introduction of the conductive foreign material is considered to have no effect on the stationary and moveable contact functionality because the insulation surrounding these components does not allow contact with any other conducting material. Because the thickness of the silver plate is so thin (0.0001" to 0.0005"), if the flaking mnaterial were to make contact between the stationary and movable contacts during an opening event, it can be presumed that the foreign material would be vaporized due to the high curr'ent levels without any effect on the item's functionality. Note that due to the distance between the stationary and moveable contacts (approximately I", reference Figure 9) when the unit is in the open state, it is highly unlikely that a flake large enough to bridge this gap would occur and if such an event did occur the flake would most likely vaporize due to the thinness of the material. In addition, the likely-hood of binding occurring in the moveable or stationary contacts is not probable because the flaking material is so thin that the movement of either part would crumble the flakes.

Page 2 ofl1l

UNITED CONTROLS INTERNATIONAL If the flaking material were somehow able to fall through the arc quenchers and moveable contact areas, the insulation barriers present make it so that it is not possible for short circuiting of electrified component to the circuit breaker frame/ground. The only exposed electrified material that the flakes may come in contact with below the arc quenchers are identified as being the current transformer studs and terminal boards (RMvS-9 configuration only, reference Figures 12 thru 15), as well as the x-retay terminal block and x-relay coil terminal block (x-relay only installed on electrically operated circuit breakers, reference Figures 12, 16, 17).

The insulating barriers around the exposed current sensor studs and the spacing between adjacent current sensors make short-circuiting of the exposed conducting material improbable. The "

current transformer terminal boards pose the largest risk of short-circuiting because the insulating material and spacing between adjacent terminals is small; thus, introduction of conducting material between these terminals may cause interruption of operation of the connected x-relay. The x-relay terminal and coil connection have sufficient insulation barrier material and spacing to make short-circuiting improbable.

Based on the above evaluation, the improper plating of silver on the non-current carrying/copper based components of the upper stud assembly may represent a defective condition due to the possibility of short-circuit of the current sensor terminal board signals for circuit breakers configured for RMS-9 trip unit operation.

Required informnation as per 10OCFR Part 21.21 (d)(4) follows:

(i,) Name and Address of the individual or individuals informing the Commission Rob Hale President United Controls International 205 Scientific Drive Norcross, GA 30092 (ii) Identification of the facility, the activity, or the basic component supplied for sutch facility or such activity within the United States which fails to comply or contains a defect.

The items supplied to Omaha Public Power District - Fort Calhoun Nuclear Station were under purchase orders 00217277, 00217497, 00217657, and 00208727.

(iii) Identification of the firm constructing the facility or supplying the basic component which fails to comply or contains a defect.

United Controls International 205 Scientific Drive Norcross, GA 30092 Page 3 of 11

UNITED CONTROLS INTERNATIONAL (iv) Nature ofldhe defect or failure to comply and the safety hazard which is created or could be created by such defect or failure to comply.

Silver plating of the non-current carrying/non-copper based components on the upper stud assemblies of the AK-25 type circuit breaker may result in flaking of the silver plating material and may introduce conductive foreign material into the host circuit breaker.

Introduction of this conductive material creates the possibility of a short circuit between terminals of the current sensor terminal boards for circuit breakers configured with RMS-9 trip units. A short circuit of this terminal board may result in failure of the connected x-relay to operate as designed and subsequent failure of the circuit breaker.

(v) The date on which the information of such defect or failure to comply was obtained.

The silver plating issue was informted by Omaha Public Power District - Fort Calhoun Nuclear Station on October 12, 2015. On October 14, 2015 UCI initiated a recall of all items affected for inspection and evaluation.

(vi) in the case of a basic component which contains a defect or fails to comply, the number and location of these components in use at, supplied for, being supplied for, or may be supplied for, manufactured or being manufacturedfor one or more facilities or activities subject to the regulations in this Part.

Part Number Utility P~urchase Order Quantity AK-25 Type Circuit Omaha Public 00217277 2 Breaker Power District - 00217497 4 w/Amptector or Fort Calhoun 00217657 7 RMS-9 Trip Unit Station 00208727 5 Refurbished by UCI ______________

(vii) The corrective action which has been, is being, or will be taken; the name of the individual or organization responsible for the action; and the length of tinme that has beeni or will be taken to complete the action.

UCI is currently evaluating methods of removing the silver plating from the non-current carrying components of the upper stud assembly or replacing the incorrectly plated items. As a preventative measure, UCI is evaluating methods for plating of only the upper stud component. UCI has implemented additional inspection criteria during the refurbishment process to avoid silver plating of non-current carrying components.

Page 4 of 11

UNITED CON*TROLS INTERNATIONAL (viii) Any Advice related to thle defect or failure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasers or licensees.

This issue is isolated only to UCI refurbished items for a single customer. UCI advises that components requiring silver plating to be clearly defined prior to implementation.

(ix) In the case of an early site permnit, the entities to whom an early site permit was

- transferred.

Not Applicable.

If"you have any questions or wish to discuss this matter or this report, please contact:

Divya Paidy Engineering Manager dpaidy@unitedcontrols.com 770-496-1406 x 106 Sincerely, Rob Hale President United Controls International Page 5 ofi11

7 Figure

...... ... 1 (Arc Runner Front, Figure 2 (Arc Runner Back, Bubbling Exhibited) Bubbling Exhibited)

Figure 4 (Lower Bracket Back)

S Figure 3 (Lower Bracket Front)

Page 6 ofIlI

] Exhibited) Figure 6 (Pin. Flaking Exhibited)

Queches ArcQe Ar*.ece Figure 7 (Assembled Circuit Breaker) Figure 8 {Assembled Circuit Breaker)

Page 7 o f 11

SStationary Contacts]

in MvebleCotacts Figure 9 (Installed Upper Stud Assemblies. Arc Quenchers Removed & Not Silver Plated)

Figure 10 (Removed Upper Stud Assembly. Front)

Page 8 of 11

Upper Stud Figure l I (Removed Upper Stud Assembly, Side)

Current Sensors Current Sensor Terminal Boards

+ X-Relay Terminal & Coil Terminal Blocks (Not Visible. Behind)

Figure 12 (Assembled Circuit Breaker. Exposed Electrified Component Areas Located Below Arc Quenchers Noted)

Page 9 o f 11

{J I( ] I ( I I III

. ON [

A Senor z[Sud Figure 13 (Current Sensor Studs. Front)

T erminal Boards 1-igure 14t ('. urrent sensors 6: [ermineal Jzoarcls, tiottom)

Page 10 ofll

Figure 15 (Current Sensor Terminal Boards) igure 17 (X-Relay Coil Terminal Block)

Page 11 ofll