United States Nuclear Regulatory Commission - Protecting People and the Environment

ABB

August 2, 2000 Page 1 of 3

Document Control Desk
US Nuclear Regulatory Commission
Washington, D.C. 20555

SUBJECT: Defective Double Pole, Double Throw relay on ABB product type 27N, 87B, 81, 47H and 50D 10CFR 21.21(b)

NOTIFICATION BY: ABB Automation Inc.
Substation Automation and Protection Division
7036 Snowdrift Road
Allentown, PA 18106
Dennis Haring
Quality Assurance

On July 28, 2000 the Allentown plant RMR department received two 87B relays from Cutler-Hammer for repair. The reported problem was that both 87B relays tripped without any AC input signal applied. The repair technician at Allentown was able to duplicate and verily the customer's reported problem. The cause of the failure was determined to be a defective double pole, double throw relay made by Siemens. The part number is RTE24048.

A development Engineer then assisted the repair technician in analyzing the failed relay. Upon removal of the relay's housing, we noticed rust on and around the armature of the relay. Rust particles and water droplets were also found inside the housing of the relay. The rust caused the armature to stick, which held the normally open contacts closed.

A subsequent review revealed that Technicians at two work cells experienced similar test failures of this part. The technicians reported various failure modes including no contact operation and intermittent operation of the relay contacts. Three failed relays were collected from one work cell and five failed relays from the other work cell. Upon removal of the relay housing, we found rust and water droplets similar those found on the relays returned by Cutler-Hammer. The relay is purchased as a sealed part.

We then called the manufacturer of the faiIed relay (Siemens) and talked with a Product Engieeer who indicated that there may have been a problem with the epoxy seal on the underside of the relay housing. If the seal is defective, it could allow water to get into the relay housing during our wave



ABB Automation Inc.
Substation Automation and Protection Division Telephone: 610-395-7333
7036 Snowdrift Road Fax: 610-395-1055
Allentown, PA18106
ABB

Page 2 of 3

solder and wash process. At this point, we collected all of the Siemens relays remaining in our plant and segregated them to stop any additional usage of this part.

On July 31, 2000 the ABB Allentown plant put seven new Siemens relays through our wave solder and cleaning process and then removed the housing of the relay. No water or rust was found inside any of the seven relays. However, we then tested 67 relays that had gone through our wave solder process earlier in the week. Of the 67 relays, 19 failed test. 14 of the 19 relays did not operate when the coil was energized and 5 of the 19 relays read a voltage from the common pole to the far side of the open contact indicating that the normally open contact was at least partially closed.

We then contacted the same Product Engineer who we spoke with at Siemens on July 28, 2000. He confirmed that there was indeed a problem with the Epoxy seal on this part and that Siemens relays with a date code prior to the 10th week of the year 2000 would be affected. The date code on the failed relays is the 8th week of the year 2000. The Siemens relays were manufactured in Austria using a one step epoxy sealant. The reported problem with the epoxy seal is two fold. First there rnay be an insufficient amount of epoxy used and secondly the curing method for the epoxy (UV light) was not effective enough to guarantee a complete seal. As a result, the seal rnay not be effective during the wave solder and washing process. Samples of both failed relays and new unused relays have been sent to Siemens for analysis.



On August 1, 2000 a check on our 1E Quality Records indicated that some of these suspect relays shipped on 1E nuclear safety related orders. The following customers and product are affected:

Oyster Creek Nuclear Station, Purchase Order 0758912 Qty 8 27N relays, Catalog Number 411T6375-HF-L with serial numbers 4218 through 4225.

Peach Bottom Atomic Power Station, Purchase Order 90178787 Qty 9 87B relays, Catalog Number 419B0042-V with serial numbers 6649 through 6657.

Limerick Generating Station, Purchase Order 90179469 Qty 1 81 relay, Catalog number 422B1275 with serial number 9116.

ABB Florence South Carolina for end user Cleveland Electric Illuminating Co. Purchase

Order PC02190 Qty I 50D relay, Catalog Number 468T4575 with serial number 20288 and Qty 2 47H relays, Catalog number 412N0175 with serial numbers 21678 and 21679.

ABB Automation Inc.
Substation Automation and Protection Division Telephone: 610-395-7333
7036 Snowdrift Road Fax: 610-395-1055
Allentown, PA18106
ABB

Page 3 of 3

ABB Automation in Allentown will notify these customers and recommend that these relays be returned to the Allentown plant to have the Siemens relay replaced by another approved manufacturer's relay. A Product Advisory Recall letter will be sent to customers who received affected product for non-safety related applications.

Prepared by Dennis Haring _______________________

QA Supervisor, Substation Automation & Protection Division, Allentown plant

Reviewed by Dennis Batovsky_______________________

Quality Manager, Substation Autornation&Protection Division

Reviewed by Gary Campbell_______________________

General Manager, Substation Automation & Protection Division

ABB Automation Inc.
Substation Automation and Protection Division Telephone: 610-395-7333
7036 Snowdrift Road Fax: 610-395-1055
Allentown, PA18106
ABB
Page Last Reviewed/Updated Thursday, March 29, 2012