Low Power J Boxes

Low Power J Boxes

The second class of junction box is the Low Power J-Box (LP J-Box) that receives input voltage at 48 Volts DC and an input data link at 10/100Base-T. The LP J-Box also has eight instrument ports that provide 12 to 48 V and has 10/100BASE-T, RS232 or RS485 data links. The junction boxes will include a pressure housing mounted on a frame with wet-mateable connectors. The ROV wet-mateable connectors will be on the outside of the frame for access by an ROV. Depending on what will be connected to a specific LVN and node location, not all of the possible ROV wet-mateable connectors may be populated. Depending on the distance from the J-Box, the J-Box is attached to a short (<100 m) cable with a wet-mate connector to plug into the junction box or it may just have a wet-mate connector on its frame that the input cable will be plugged into. If a sensor that is attached to the junction box is not attached its frame it may connect to the junction box through a wet-mate connector. Junction boxes are key to adapting the system to numerous types of sensors with a few standard infrastructure components. The initial RSN architecture will deploy junction boxes to support core instrumentation and sensors, with anticipation that more will be added during the 25-year life of the OOI to expand the coverage area and number of sensors on the network. Additional finormation about nodes and junction boxes is provided in the RSN Secondary Infrastructure White Paper, 2007.