Guidelines for estimation of cabinet dynamic amplification

The use of GERS (generic equipment ruggedness spectra) for screening purposes in plant relay evaluations requires the comparison of relay GERS to mounting point response spectra. At best, only rough estimates of floor spectra (base input to an enclosure or panel0 are available. Since at the outset of a relay evaluation the specific location of a given relay is, in general, unknown, a simple approximate method of estimating the mounting point response is desirable. Based upon review of test data and judgmental evaluation of narrow- and broad-band response comparison, conservative single value amplification factors are recommended. Examples of MCC (Motor Control Center) and flexible panel screening amplification factors are presented. Screening amplification factors of 3.0 and 6.0 for MCC and flexible panels, respectively, are recommended for use in relay evaluations. (orig.)