Information Notice 1988-69, Movable Contact Finger Binding in Hfa Relays Manufactured by General Electric (GE)

Movable Contact Finger Binding in Hfa Relays Manufactured by General Electric (GE)

ML031150179
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, 05000000, Zimmer, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	08/19/1988
From:	Rossi C Office of Nuclear Reactor Regulation
To:
References
IN-88-069, NUDOCS 8808190195
Download: ML031150179 (9)

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 August 19, 1988 NRC INFORMATION NOTICE NO. 88-69: MOVABLE

CONTACT

FINGER BINDING IN HFA RELAYS

MANUFACTURED BY GENERAL ELECTRIC (GE)

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

This information notice is being provided to alert addressees to potential

problems resulting from binding of the movable contact fingers in HFA relays

manufactured by GE. It is expected that recipients will review the information

for applicability to their facilities and consider actions, as appropriate, to

avoid similar problems. However, suggestions contained in this information

notice do not constitute NRC requirements; therefore, no specific action or

written response is required.

Description of Circumstances

On August 12, 1988, GE submitted a written 10 CFR Part 21 notification to the

NRC concerning binding of the movable contact fingers in HFA relays. GE stated

that one user of HFA relays had reported difficulty making wipe and gap settings

on some of their HFA relays due to binding of a movable contact finger in the

phenolic support assembly. The root cause of the binding was determined to be

movable contacts that were manufactured wider than the allowable tolerance.

These wider contact arms may not float freely in the slot provided in the phenolic

support. GE also stated that the binding of a movable contact arm could inter- fere with the relay contact wipe, and that proper contact wipe is necessary to

maintain correct operation and seismic rating of the relay. In addition, GE

recommended that all HFA relays having a date code prior to WC (September, 1988)

be checked to determine if a movable contact finger binding condition exists.

A copy of the GE 10 CFR Part 21 notification is provided as Attachment 1.

The primary purpose of this information notice is to promptly alert addressees

of this situation.

Addressees

may wish to promptly contact GE concerning ad- ditional details related to the potential for HFA relays not performing their

intended function. The NRC staff is continuing to review this situation. Ad- ditional regulatory action will be taken, if appropriate, upon completion of

the staff's review.

8808191 A1

IN 88-69 August 19, 1988 No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact one of the technical

contacts listed below or the Regional Administrator of the appropriate regional

office.

i, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Technical Contacts: Ray Scholl, NRR

(301) 492-1171 Jack Ramsey, NRR

(301) 492-1167 Attachments:

1. GE 10 CFR Part 21 Notification dated August 12, 1988

2. List of Recently Issued NRC Information Notices

IN 88-69 August 19, 1988 No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact one of the technical

contacts listed below or the Regional Administrator of the appropriate regional

office.

es E i, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Technical Contacts: Ray Scholl, NRR

(301) 492-1171 Jack Ramsey, NRR

(301) 492-1167 Attachments:

1. GE 10 CFR Part 21 Notification dated August 12, 1988

2. List of Recently Issued NRC Information Notices

GE Meter & Ccntro!

Attachment 1

'- -c IN 88-69 August 12, 1988

Mr. Vince Thomas

United States Nuclear Regulatory Commission

Washington, DC 20555

SubJect: Type HFA relay with movable contact finger binding

Dear Mr. Thomas:

under lOCFR21 This letter is to notify you of a reportable condition

department.

related to HFA auxiliary relays manufactured by our

an investigation

We classified this as a reportable condition after wipe and gap

of a report from a customer who had difficulty in making

contact finger.

settings on HFA relays due to binding of a movable

to all

The attached service advice letter 192.1 is being sent equivalent on

specified "Nuclear IE", or

purchasers of these relays who

a possible binding

the order. The attachment explains the nature of of the relay if a

condition. Users must determine from their application

safety hazard could be created by such condition.

1988)

All HFA relays having a date code prior to WC (September, advice to determine if a movable

should be checked per the service

contact finger binding condition exists.

Sincerely yours, S. S. Duerwachter

Manager, Marketing and

Product Engineering

/fb

Attachment

GE MIeter & CcntroI

'5~e3 ,:: r:'. Attachment

IN 88-69 RELAY AND ACCESSORY SERVICE ADVICE LETTER

SubJect: HFA Moving Contact Finger Binding Number 192.1 Issued by: August 12, 1988 R. R. Hammer

Prepared by: S. S. Duerwachter

One user of HFA relays has reported difficulty making wipe and gap

settings on some of their relays due to binding of a movable contact

finger in the phenolic support assembly.

Our investigation of the suspect devices has conf;rnied the binding and

identified the root cause as moving contacts which were manufactured

wider than the allowable tolerance. The wider contact arm may not float

freely in the slot provided in the phenolic support. The binding of the

moveable contact arm could interfere with the relay contact wipe. Proper

contact wipe is necessary to maintain correct operation and seismic

rating of the relay.

Tooling used to manufacture the contacts has been corrected and applied

to relays manufactured after August 12, 1988, date code WC and later.

Relays made before this date should be checked for possible binding.

Although the impact of this Service Advice effects all relays in service, the test to determine if the problem exists is easy and the risk for in

service failures is remote.

Binding of the movable contact fingers may be identified by pulling each

moving contact toward the front of the relay until the finger hits Its

stop, then depressing it toward the back of the relay until no further

movement is possible. Next gradually remove the force applied. When all

force is removed, the moving contact should return to its original

position. A binding contact finger will not freely return to its

original position.

If finger binding is experienced, replacement relays or contact armature

assemblies are available as follows:

For NuclearlE Applications, a replacement relay is recommended.

Replacement relays should be ordered through your local GE district

office. Relays ordered before October 1, 1989 will be furnished at sales60%

of the published handbook price. Requests for replacement HFA's must

include:

Attachment 1 IN 88-69 Page 2

Service Advice Letter 192.1

A. Relay model number and contact code

B. A reference to Service Advice No. 192.1 C. Requisition number and purchase order under which the original

relay was furnished

D. Nuclear Damage Waiver

For Non-lE Applications, a replacement contact armature assembly is

recomiended.

Installation of the assembly may be accomplished by following the steps

outlined on Attachment A. Replacement armature assemblies are available

on a no-charge basis and should be ordered through your local GE district

sales office. Requests for the armature assemblies must include:

A. Relay model number and contact code

B. A reference to Service Advice No. 192.1 C. Date codes of the relays for which the replacement armatures will

be used.

Replacement armature assemblies will be available through October 1,

1989. Labor for installation of the armature assemblies or relay are the

responsibility of the purchaser.

Attachment 1 ATTACHMENT A - S. A. 192.1 IN 88-69 The contact armature assembly should be replaced and adjusted as follows

to maintain proper relay operation.

REPLACEMENT

1. Remove the screw and lock washer holding the moving contact

pigtails to the base for each of the six moving contacts.

2. Lift the control spring adjusting screw out of the armature slot

and let it move to a rest position.

3. Slide out the existing contact and armature assembly and replace

with new assembly.

4. Fasten the moving contact pigtails to the base with the existing

screws and lock washers.

5. Form the pigtails in a loop without any kinks.

6. Replace the control spring adjusting screw in the armature slot.

ADJUSTMENTS

1. All normally open "a' contacts shall have a wipe of 3/64 to 3/32 of an inch. This can be adjusted by forming the moving

contacts. If the relay has only normally open contacts, the stop

screw should be adjusted to give approximately a 7/32 inch

contact gap.

2. All normally closed "b" contacts shall have a wipe of 0.067 inches + .010 inches. This can be accomplished by using the stop

screw as a more accurate wipe measurement. The proper wipe can

be obtained by forming the moving contacts.

3. Connect a continuity light to each of the normally closed

contacts.

4. Loosen the stop screw locknut and turn the stop screw clockwise

until the first cf the normally closed contacts open.

5. Turn the stop screw an additional 1-1/4 turns and all the

nonmally closed contact lights should go out indicating that the

normally closed contacts are adjusted within 1/32 of an inch

overall from the first open to the last open.

6. Return the stop screw so that there is approximately 1/8 inch

between the end of the stop screw and armature and then tighten

the lock nut.

ELECTRICAL TESTS

Set the relay pickup between 55-61% of rated for DC relays and between

75-81% of rated for AC relays by adjustment of the armature control

spring.

Attachment 2 IN 88-69 August 19, 1988 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

88-48, Licensee Report of Defective 8/24/88 All holders of OLs

Supplement 1 Refurbished Valves or CPs for nuclear

power reactors.

88-68 Setpoint Testing of Pres- 8/22/88 All holders of OLs

surizer Safety Valves with or CPs for nuclear

Filled Loop Seals Using power reactors.

Hydraulic Assist Devices

88-67 PWR Auxiliary Feedwater Pump 8/22/88 All holders of OLs

Turbine Overspeed Trip or CPs for nuclear

Failure power reactors.

88-66 Industrial Radiography 8/22/88 All NRC industrial

Inspection and Enforcement radiography licensees.

88-65 Inadvertent Drainages of 8/18/88 All holders of OLs

Spent Fuel Pools or CPs for nuclear

power reactors and

fuel storage facilities.

88-64 Reporting Fires in Nuclear 8/18/88 All holders of OLs

Process Systems at Nuclear or CPs for nuclear

Power Plants power reactors.

88-63 High Radiation Hazards 8/15/88 All holders of OLs

from Irradiated Incore or CPs for nuclear

Detectors and Cables power reactors, research reactors

and test reactors.

88-62 Recent Findings Concerning 8/12/88 All holders of NRC

Implementation of Quality quality assurance

Assurance Programs by program approval

Suppliers of Transport for radioactive

Packages material packages.

88-61 Control Room Habitability - 8/11/88 All holders of OLs

Recent Reviews of Operating or CPs for nuclear

Experience power reactors.

OL = Operating License

CP = Construction Permit

IN 88-69 August 19, 1988 No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact one of the technical

contacts listed below or the Regional Administrator of the appropriate regional

office.

Charles E. Rossi, Director

Division of Operational Events Assessment

Office of Nuclear Reactor Regulation

Technical Contacts: Ray Scholl, NRR

(301) 492-1171 Jack Ramsey, NRR

(301) 492-1167 Attachments:

1. GE 10 CFR Part 21 Notification dated August 12, 1988

2. List of Recently Issued NRC Information Notices

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