Document oMyzgb3OQj0XOVKeLoMJqDk2g

FILE NAME: Electrical Insulation (ELEC) DATE: 1985 May 15 DOC#: ELEC016 DOCUMENT DESCRIPTION: Memo 1 tan Ease Pittsburgh, 9N40 WW 299-4741 WiB - May 15, 1985 SuSieci Atlantic Electric Co. Air Circuit Breakers - Tm j p Asbestos /U-, /ja-c C 4 -& 7 M //1 (A}071? Y f/z t J Allentown Office - Jack Sobo ta Reference Customer's letter of March 21, 1985 to you regarding asbestos in breaker arc chutes. Prior to 1977 all type DH and DHP breaker arc chutes were built with asbestos r o p e spacers between the ceramic plates of the interrupter stack assembly. Thn 6pacerB were formed by flattening 3/16" diameter asbestos rope to approximately 1/8" thickness. Theasaemblies were held together with a white baking enamel w h i c h covered the asbestos rope except for the 1/8" exposed surface between the ceramic places. Starting approximately January 1, 1977 the asbestos rope was replaced by glass r o p e in all DH and DHP arc chutes. In addition to the asbestos rope DH aud DHP arc chutes, depending oh the rating a n d vintage, may have some pieces of asbestos cement board in them. This is a hard, dense (90 lbs/cu.ft) asbestos fiber-hydraulic cement board which contains approximately 29% asbestos. This material is still being used, T h e asbestos content of the arc chutes in question is as follows! 50DH150 - Asbestos rope Asbestos board - approx. .15 lba - approx. ,28 lba (29% X .98 lba) Total % Asbestos - 1.1% ^.15 + .28 X 100, L 40 ' - 50DH150E - Asbestos rope Asbestos board -- approx. .175 lbs - approx, .77 lba (29% X 2.64 lba) Total % Asbestos 0.95% ,.175 * .77 X 100, ' 100 lSODHPSOO - Built prior to January 1977 licarjae: Asbestos rope Asbestos board - approx. .4 lb - approx. .25 lba (29% X .84 lba) Total 7. Asbestos - 0.26% ..4 * .25 X 100. ' .250 ' Exhibit f .7) CORK-4490 uf^i^od - 2- 150DMP5Q0 - Built after January 1977 Asbestos board - .25 lbs (29% X .84 lbs) Total Z Asbestos * Under normal handling or operation, flberous asbeacos Is not given off. If the breaker has undergone a major fault current Interruption, there is a remote possibility that a few fibers of asbestos could.be released. Therefore, prior to the breaker being examined for maintenance or other reasons, the following procedure should be used. The breaker and assembly should bo completely de-energized p e r the prescribed procedure given in the instruction manual, When de-energized, a n y particulate matter should be removed by a damp cloth from the inside of the cubicle and the exterior of .the breaker and arc chute assembly. (Note* The equipment should be dry before any electrical testing. The cloth should be disposed of by approved methods for asbestos waste material). W hen cleaning the interior of the arc chutes, which involves blowing dry compressed a i r thru .them, some flberous asbestos may be blown off. Therefore, personnel should be protected using NI0S11 approved personnel protection equipment. A. tomeo, Manager M.V. C.O.E. COliIC-4491