SeaPerch Remotely Operated Vehicle, Construction Manual, Page: 17 / 110

SeaPerch ROV Construction Manual
– Version 2010-04NW
S-5
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Watch Out for Squirting Wax: During the final step of thruster potting,
when the lid is placed onto the thruster housing, melted wax can squirt
out of the small hole in the lid where the wires pass through. If the lid is
pressed quickly into place, wax can even squirt as high as the ceiling or
onto nearby walls and people. Placing a paper towel over the lid and
pressing slowly is recommended to avoid the wax-squirting problem.
Protect nearby walls and floor areas with paper or tarps. Obviously,
everyone in the area should be wearing eye protection.
Safety With Electricity and Batteries
The low-voltage (12 volts, direct current (DC)) battery power source used
with SeaPerch ROVs is relatively safe and well-
proven in students’ hands.
However, they should be cautioned about potential problems from short-
circuits as well as electrical safety issues in general.

Battery Short-Circuit Hazard: Although the battery can be used quite
safely when it is connected properly to the ROV, it can be damaged,
cause wires to melt, or even start a fire if its positive and negative
terminals are connected directly together. That is called a “short circuit,”
and it will allow the battery to essentially discharge all of its stored
energy at once. Besides resulting in sparks when such an improper
connection is made, the wire or metal object shorting across the terminal
will immediately become extremely hot and may even melt. That could
obviously cause burns or ignite an object in contact with the shorting
material. Never connect anything between the battery terminals except
an appropriate electrical “load” such as the ROV circuitry, through its
fused power cord. Be careful to keep the battery terminals covered or
away from all wires and metal objects when not in use. Do not connect
the ROV circuitry or components to the battery until instructed to do so.

Avoid Creating Other Short Circuits During ROV Construction:
When wiring circuits or conducting tests, take care to avoid unintended
connections or accidental short circuits. While handling partially or fully
completed circuits, ensure that wires do not move and touch together
where they should not. Always check the circuitry carefully and conduct
the recommended tests before connecting the battery.

General Electrical Safety: When working with electrical circuits with
power applied, do not allow any body parts to
“become part of the
circuit.
” In other words, do not touch both the positive and negative
terminals of a battery with your hands or touch a battery terminal with
one hand and part of the circuitry with the other. Make sure that all
switches are in their off positions while connecting or disconnecting the
battery, and connect just one power wire at a time.