Ten Deadly Conditions to Check for in Your Boat's Electrical System - Part 2
http://www.bluesea.com/Article_detai..._ID=292&id=387
In the September newsletter, 1 through 5 of the ten deadly conditions were presented at: http://www.bluesea.com/Article_detai..._ID=292&id=383
Deadly conditions 6 through 10 are presented below
6. Using non-ignition protected devices in explosive areas, or, making areas explosive with
dinghy fuel and
barbecue bottles
It is dangerous to store
dinghy fuel or portable
barbecue bottles on board boats that are not designed for ignition protection. This includes
diesel propulsion fuel or gasoline-fueled systems for externally mounted
outboard motors. Bringing alternative fuels on board, even in small quantities, can lead to explosive situations.
7. Hot/Neutral reversal on AC connectors at the
dock or onboard
If a shore cord is incorrectly wired so that the hot and neutral wires are reversed, there is inadequate AC circuit protection. Your boat should have a two pole main breaker if wired for 120V. It should also have a reverse polarity indicator or warning device.
8. Undersized or absent
inverter and
charger DC grounding
Inverters and
battery chargers are bridges between a boat's AC and DC
power systems. The high voltage of the AC system presents a shock hazard and can be lethal if it exists on an ungrounded case. The DC system is not normally a shock hazard but can provide a lot of current, and so is potentially a source of fire. A suitable ground must be installed between the AC and DC system.
9. Missing or faulty GFCI
According to the ABYC Standards, when an AC receptacle is installed in a
head,
galley, machinery space, or on a
weather deck, it shall be protected by a Type A Ground Fault Circuit Interrupter (GFCI). These GFCI's protect receptacles and therefore the
appliances that are plugged into them. It is possible to use the output of one GFCI receptacle to feed other receptacles and permanently-wired devices thereby protecting these downstream receptacles and devices.
10. Operating power tools in potentially explosive atmospheres
Portable power tools operated by
batteries or by AC have brush-type universal or DC motors. The spinning commutator generates sparks and the space is usually well ventilated and even has a fan forcing outside air through the space.
Electric drills, routers and saws are bad. Shop vacuums are worse. They are designed to collect air and dirt through the hose and bring it inside. The air passes through a filter and then some of it through the
motor. More than one explosion has taken place when a wet/dry vacuum was used to vacuum up a fuel spill in the
bilge. A shop vacuum is a wonderful way to pick up water spills, but it also excellent at mixing and igniting explosive gas. Nobody thinks about getting killed by a vacuum cleaner but it can take out the operator, the boat and possibly the neighbors!
Blue Sea Systems, Inc. Copyrighted 2006.