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� � <br /> Vcrizon Ylirelcrs <br /> $i=hQ ri�illN•00(j <br /> within a District I of the city. As the support cabinets are expected to operate 24 hours a day, <br /> they must meet the 45 d8(A) nighttime limit. <br /> Additionally, Everett Municipal Code 20.08.050 allows that during any one-hour period, the <br /> maximum permissible noise level may be exceeded by 5 d8(A)for a 15 minute period. <br /> Therefore, the generator must not exceed 60 dB(A) when running during daytime hours for <br /> maintenance testing. The generator is exempt during emergency operation. <br /> Predicted Equipment Sound Levels <br /> 24-Hour Operafion Equipment <br /> The proposed 24-hour operation equipment includes three Lucent Modcell 4.OB cabinets (two <br /> proposed and one future) and two Em�rson EBRE Baltery Cabinets. According to manufacturer <br /> data, the Lucent Modcell 4.08 has a snund power level of 65 d8(A) at 25'C. The manufacturer <br /> specifies lhe noise level for the Emerson EBRE Battery Cabinet is a maximum of 71 dB(A) at 5 <br /> feet with air conditioning unit and alarm installed'. The combined sound pressure level from the <br /> five cabinets is 74 d6(A) at 5 feet. <br /> To predict equipment noise levels at the receiving properties, this survey used the methods <br /> established by ARI Standard 275-97. Application factors such as location, height, and re8ective <br /> surfaces are accounted for in predicting the sound level at the nearest receivers. <br /> The nearest receiving property is 44 feet soulh of the equipment location. The proposed <br /> equipment is to be located on a 16 feet by 8 feet concrete pad to the south of the electric <br /> substation. The predicted sound Ievel at the nearest property is shown in Table 1 below. <br /> Table 1 <br /> Application Factors and Predicted Noise Levels <br /> Pro osed New E ui ment <br /> Line A lication Factor South <br /> 1 Combined Sound I'ressure Level at 5 ft. dBA , L 1 74 <br /> 2 Distance Factor(DF) -19 <br /> Inverse-S uare Law Free Field : DF = 2010 d1/d2 44 ft <br /> 3 New Equipment Sound Pressure Level at Receiver, Lpr 55 <br /> Add lines 1 and 2 <br /> As shown in Table 1, the combined sound pressure level from the proposed equipment cabinets <br /> at the nearest receiving property is 55 dBA which exceeds the 45 dBA code limit. <br /> Noise mitigation measures are necessary to meet the City of Everett noise code for the support <br /> cabinels. The inslallation of a noise barrier will reduce !he noise level to acceptable levels. <br /> 'Noiu Jata ohuinnUtom Iinxnnn tirt H.fNW OTU\Icl.can Air CunJilioning unit installd on cabincl. <br /> k�<"�{ll � <br />