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95125 ACCESSION #: 9505240268 ABB RECORD OF EVALUATION SUBJECT: 10CFR 21 Report of Product Defect - Mismarked AMP #12-10 Insulated Lugs at San Onofre Nuclear Generating Station - Southern California Edison. 1.) Description of Deficiency: AMP Inc. #12-10 insulated lugs were found to have been used with #14 gauge wire in ABB 4160V-5HK and 480V K-Line Switchgear, supplied by ITE in 1976. The yellow barrel of the mismarked lugs had 3 black stripes indicating for use with #16-14 gauge wire. The lugs were stamped #12-10. The use of the oversize lugs led to out-of- specification measurements during pull tests 2.) Location and Date: This deficiency was discovered at the San Onofre Nuclear Generating Station - Southern California Edison on March 14, 1995. The switchgear was shipped in 1976. 3.) Analysis of Safety Implication: A thorough analysis was conducted by San Onofre Nuclear personnel (see attachment #1). The oversize lug connections have not failed and are not of an immediate reliability concern based on this laboratory analysis and the extended time frame the lugs have performed satisfactorily. However, the mismarked lugs represent a potential source of failure from pullout due to any unusual load application (such as a seismic event) that could effect Safety Related Equipment. 4.) Conclusions: Research indicates that the mis-marked lugs were probably delivered in a lot and were issued to manufacturing floor stock. Therefore, other equipment supplied by ITE and Gould ITE in the 1975-1977 time frame might have the same type of mis-marked lugs, including equipment in 1E applications (see attachment #3). K-Line and HK switchgear equipment with Amp insulated lugs should be inspected for mis-marked/oversized lugs and changed to the proper size lug during the next scheduled outage. Contact Components Marketing at (407) - 323-8220 x130, x131, x132, or x157. 5.) Reference Documents: Attachment #1 - Report generated by San Onofre Nuclear personnel. Attachment #2 - Acknowledgment from AMP Inc. in regard to their evaluation of samples of the mismarked lugs. Attachment #3 - Customer List. 6.) Corrective Action: All AMP lugs currently in inventory at ABB, Distribution Systems Division were inspected for this discrepancy on May 3, 1995. No mismarked lugs were found. Training was held with QA personnel on this finding. ABB Power T & D Company Inc. Distribution Systems Division Telephone: Telefax: 201 Hickman Drive 407 323-8220 407 322-8934 Sanford, FL 32771-8201 (Marketing/Engineering) 407 322-8938 (Operations) 407 328-9264 (Human Resources) ABB 7.) Action to Prevent Recurrence: All AMP lugs utilized on Nuclear Safety Related switchgear will be subject to 100% inspection. 8.) Point of Contact: Point of contact for ABB, Distribution Systems Division in Sanford, FL is David Stone, Quality Assurance Manager, (407)323-8220, ext. 159. 9.) Prepared By: This report prepared by David Stone. 10.) Reviewed By: Aubrey Jackson - Total Quality Manager Norb Hagenhoff - Vice President/General Manager ABB Power T & D Company Inc. Distribution Systems Division Telephone: Telefax: 201 Hickman Drive 407 323-8220 407 322-8934 Sanford, FL 32771-8201 (Marketing/Engineering) 407 322-8938 (Operations) 407 328-9264 (Human Resources) Initial Root Cause Evaluation of 2A04/2B04 Oversized Lugs April 12, 1995 On March 14, 1995 during the 2A04 bus outage, an associated bus conductor wire was pulled free of it's crimped lug. The replacement of the DC control power molded case circuit breakers was in progress at the time of failure and closer examinaton revealed that the affected lugs were those attached to the control power breaker. These lugs were distinctly marked by a yellow jacket trimmed with three black stripes and a #10 size terminal ring. The problem lugs were manufactured by AMP but other unaffected Hollingsworth lugs were also removed for comparison with the odd-sized AMP lugs. The wiring was part of original panel equipment supplied to SCE by the vendor, ITE. The removed AMP lugs were stamped AMP 12-10 and contained a yellow barrel with three black stripes. Mr. Steve Bortner, AMP Inc, Jacobus, PA, confirmed that the yellow/black striped barrel lug should represent a 16- 14 heavy duty (HD) lug, not a 12-10 lug. The mismarked 12-10 lugs were also confirmed by the #10 ring with a thickness of about .041". All lugs were inspected and replaced as necessary on the two cleared busses (2A04 and 2B04) under NCR's 95030100 and 95030097. Only the AMP lugs were found to be mismarked whereas the Hollingsworth 16-14 HD lugs were correctly marked and of no safety concern. The other Safety Busses have been scheduled for inspection per the following NCR's: 95030105 (2A06); 95030106 (2B06); 95030107 (3A04); 95030108 (3B04); 95030109 (3A06); and 95030110 (3B06). Three oversized lugs (12-10 mismarked lugs with #14 wires attached) were removed from 2B04 and cut open for physical examination in the laboratory. The three lugs showed no signs of arcing, burning, overheating or other electrical degradation. There were indentations on all three lugs which showed the wires had physically pressed into the lugs while flattening on one side. A transfer of material from the lug to the wire had also occurred in all three samples. Pull tests were performed on both oversized lugs (12-10) from 2B04 and three normal 16-14 HD lugs taken from the 2BE15 motor starter. The pull tests revealed that the oversized lug connections were not as strong as the normal ones. The oversize 12-10 lug failed at a load of 32.7 lbs. where the wire pulled out. Three additional oversized lugs were tested and those wires all pulled loose at about 30 lbs. The three normal 16-14 HD lug connectors didn't pull loose until the load exceeded 100 lbs (109 to 121 lbs). AMP specifications list 70 lbs as the minimum pullout force expected on a normal connection involving a 16-14 HD lug and #14 wire. The NEMA Standard lists 40 lbs as the minimum force required for wire pullout. Attachment #1 The conclusions from this examination are: 1) the oversized lugs have not electrically degraded and 2) there is some mechanical strength developed in the oversized connections although it is only about 75% of the NEMA Standard. Laboratory examination of the inside surface of three oversized lugs revealed no evidence of overheating, corrosion or oxidation. The metal to metal connections were intact and there was evidence of crimp compression on both the wires and inside of the lugs. The oversize lug connections are not of an immediate reliability concern based on this initial laboratory analysis and the extended timeframe (14 years plus) the lugs have performed satisfactorily. However, the mismarked lugs represent a potential source of failure from pullout due to any unusual load application (such as a seismic event) that could effect Safety Related equipment. Additional testing and evaluation will be preformed in support of a Failure Analysis Report to be prepared on this subject. It was concluded that all oversized lugs initially provided by ITE in similar switchgear should be changed out at the very next bus outage of sufficient length. ITE (now ABB) should consider preparing a Part 21 Report or other appropriate means of warning other potentially affected users of the above described defect. Please notify us and other affected companies of your decision concerning the Part 21 Report. AMP 250 N. Main Street Jacobus, PA 17407-1098 Phone: 717-428-4500 Automotive/Consumer Business Group April 24, 1995 Tom Graham Southern California Edison Company P.O. Box 126 San Clemente, CA 92674 Fax: 714-368-9167 Dear Tom: I received the samples of our terminals that you found in your ITE circuit breakers. The samples were incorrectly marked. The wire barrel body was a 12-10 size and they had 16-14 HD sleeves on them. The sleeves were yellow with 3 black stripes. This is not an industry standard for marking 16-14 HD. In examining these samples, it should be noted that they were manufactured many years ago. Although I have no explanation how this happened, I do know that this error was very rare. In checking our history files I did not discover any complaints of this nature. If I can be of assistance, please do not hesitate to call. Respectfully, Steve Bortner RBY Team Eng. Phone: 717-428-4542 copy: Roger Stoker, Fax: 714-368-(illegible) SB/mj file: sbll Attachment #2 Table "ABB DISTRIBUTION SYSTEMS DIVISION" omitted. Attachment #3 *** END OF DOCUMENT ***