Cerulean 300m Electronics Enclosure Assembly

Assembly of the 300m Electronics Enclosure is analogous to mounting the electronics on the Electronics Stack Base.

First, assemble the cable penetrators to the case top. Don’t forget the penetrator O-rings. They need a light grease coating. Be sparing; lots more is not better. Leave the vent plug out or loose until assembly is complete. Leaving it out makes it less likely you will forget to tighten it at the end, but also makes it more likely to attract grit or hairs on the O-ring. It doesn’t really matter which cable installs into which hole in the top.

Plug the cables into the electronics stack. The connectors are all different sizes to make it harder (but alas, not impossible for the determined soul) to plug the cables into the wrong socket. Very little force is required to insert a JST-GH connector into its socket; one or two tens of grams is typical. If the connector is not mating easily, check the orientation, alignment, and pin count. The connectors latch into place. When un-mating, squeeze the locking tab and gently pull the connector straight out. If it doesn’t come easily you are probably not squeezing the tab all the way. Pulling harder won’t un-mate the connection but it will rip the socket off the board or the wires out of the connector.

Water seal is via O-ring. The O-ring is a standard Buna -232 size. The O-ring needs to have a light grease coating. When assembling make sure there is no dust or hair or grit on the O-ring or facing surfaces (bad stuff like that is attracted to the O-ring grease). Apply a light coating of grease to the inside of the shell before assembling. Take care not to trap a wire in the O-ring. You are responsible for achieving a water-tight seal.

Carefully stuff the wires up into the top of the case and carefully slide the electronics stack into the top. As the lip of the top approaches the O-ring, rotate the top with respect to the bottom to line up the radial retention holes (it doesn’t matter which holes line up with which). Squeeze the case closed. If you feel resistance, stop and figure out what is wrong. The cables may need to be re-arranged inside.

When closed, install either the supplied nylon M3 screws or the supplied 316-stainless cap screws in the retention screw holes. The nylon screws are corrosion resistant, but if you are banging the case around they may shear off. The stainless cap screws are stronger but may corrode or develop an electrolysis reaction with the aluminum case. Our recommendation is to use the nylon screws and don’t bang the case around.

Finally, install and/or tighten the vent plug in the top.