Abstract: A method and apparatus for identifying a ground fault in a motor drive system that includes at least one three phase power conditioner that is linked to three phase supply lines and to positive and negative DC buses, the method comprising the steps of controlling the power conditioner at an operating frequency to convert power, while controlling the power conditioner to convert power, controlling the power conditioner to apply a common mode signal on each of the three phase supply lines where the common mode signal has a frequency that is different than the operating frequency, sensing the common mode signal on at least one of the three phase supply lines and when the common mode signal on the at least one of the three phase supply lines is greater than a threshold level, indicating that a ground fault has occurred.

Abstract: A method and apparatus for identifying a ground fault in a motor drive system that includes at least one three phase power conditioner that is linked to three phase supply lines and to positive and negative DC buses, the method comprising the steps of controlling the power conditioner at an operating frequency to convert power, while controlling the power conditioner to convert power, controlling the power conditioner to apply a common mode signal on each of the three phase supply lines where the common mode signal has a frequency that is different than the operating frequency, sensing the common mode signal on at least one of the three phase supply lines and when the common mode signal on the at least one of the three phase supply lines is greater than a threshold level, indicating that a ground fault has occurred.

Abstract: A temporary gravesite marker for use in identifying a gravesite until a permanent gravestone is available includes a marker tablet which has a generally rectangular solid form with an upper surface to be marked with alphanumeric characters providing information regarding the deceased. The marker tablet is fabricated from a durable material and includes an upper surface and a substantially parallel bottom surface, both of which are substantially flat. The preferred marker tablet has a two-to-one (2:1) aspect ratio and measures 5-½ inches by 11 inches with a 1- 1/16 inch thickness. The density of the material selected, based upon the overall volume, yields a weight for the marker tablet of approximately ten pounds. The alphanumeric characters are inscribed into the upper surface of the marker tablet by means of a prepared stencil and by sandblasting.