Improving electrical saftey in an electrolytic cell line

Abstract

Due to the design and layout of the electrolytic cell production plant, electrical safety is challenging. The cells, which are connected in a series circuit creating a large layout, are powered by a 200–500 volt DC source, which is intentionally ungrounded to provide personnel and equipment protection. Detection of the first ground connection of the electrolytic cell line is critical to ensure safety to personnel. Traditional methods of ground connection monitoring of a cell line, such as midpoint zero-volt detection, require constant analysis of data to determine if the first ground exists. This method can easily lead to human error, since the zero-volt location changes when cells are removed or added to the cell line. Also, the midpoint zero-volt method only functions when the cell line is energized, which makes troubleshooting not only a safety concern but also difficult. Moreover, if the ground connection occurs at the zero-volt location, there is no indication of the increased electrical hazard. Protection from electrical shocks and electrocution is safety critical and requires an instrument that continuously monitors the dynamic insulation resistance-to-ground of the entire cell line. The instrument must perform this vital safety function whether the cell line is energized or de-energized, so that finding the first ground quickly is easy and can be achieved without applying power to the cell line. Existing DC ground fault detection equipment, or insulation monitoring device, used in the mass transit and other industries has been adapted to accomplish this necessary ground fault detection in the electrolytic cell line; thereby, improving electrical safety in an electrolytic cell line.