ML19268B967

Abnornal Occurrence 74-18:on 741010,1A Makeup Pump Motor Tripped on Phase Overcurrent & Ground Overcurrent.Caused by Burned Off Phase Lead in wire-to-motor Winding.Redundant Component Satisfactorily Tested

ML19268B967
Person / Time
Site:	Three Mile Island
Issue date:	10/11/1974
From:	Herbein J METROPOLITAN EDISON CO.
To:
References
NUDOCS 7910250751
Download: ML19268B967 (1)

Text

. __

~

h((l391hK J.'. c,'.~' y y, j

'E 3SLM -

HETROPOLITAN EDJSON COMPANY susswnrorcrutut ruoucunurasconmuun

>ST OFFICE DOX 4BO MIDDLETOWN PENNSYLVANIA 17057 TELEPHONE 717 344 4C41 October 11,1974 Mr. J.P. O'Reilly, Director Directorate Of Regulatory Region I 631 Park Avenne King Of Prutsia, 19t<06 Operating License DPR-50 Docket 50-289

Subject:

' Abnomal Occurrence flo. A0 74-18 ,

p

Dear fir O'Reilly:

This telegram is to confim the telecon between Lee Spessard-(Region I-AEC),

and J.G. Herbein (Station Superintendent) at 1030 hours0.0119 days <br />0.286 hours <br />0.0017 weeks <br />3.91915e-4 months <br /> 11 October 1974.

The following report is submitted in accordance with paragraph 6.7.2.a (page 6-11) of the technical specifications.

At 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br /> on 10 October 1974 the 1A l'akeup Pump Hotor tripped on phase overcurrent and ground overcurrent.

The Mahup Pm:p !!ctor tripped while perfoming the Engineered' Safeguards Loading Sequenca Quarterly Surveillance Test.. .

The redundant component (1C Makeup Picp) was satisfactorily tested.

Investigation into the 1A Makeup Pc::p overcurrent trip, revealed tJiat the A phase lead in wire to the entor winding had burned off due to a high resistance connection at the rotor tominal box.

The high resistance connection occurred through the use of a. bolt type "Burndy Quiklug," rather than the prescribed co pression lug, to connect the A phaso lead in to the rotor teminal box.

Resistance tests 4.ndicated no d: age had occurred to the c:otor winding.

.\

y