Get the basics on your in-house electrical system
By John Fleming
In the last issue we discussed the wiring on your houseboat’s engine/s. In this issue we will take up the subject of wiring in the houseboat itself. The houseboat may have a single 12-volt current source. It may also be provided with a second 120-volt current source and even perhaps a third 220-volt current source. The 12-volt current source is provided by the storage battery or batteries and replenished from the engine generator/s, the auxiliary generators, or dockside current. The 120-volt current source may be available only at the dockside or it may be provided by a separate, auxiliary, engine powered generator carried onboard the vessel.
Those large houseboats which employ a 220-volt current source may derive that current from either dockside connections only or from an auxiliary generator. This 220-volt current source may be necessary to supply power for larger appliances such as an electric range.
The wiring in any houseboat properly begins with a switch panel which employs ground fault breakers. The single panel may include switches which deliver 12 volt starting current from the storage batteries to the main engine/s as well as the auxiliary generator/s.
The 12-volt current for the bilge pump/s, bilge blower/s and all of the 12 volt accessories aboard the vessel comes through this panel. There will generally be switches for bilge pump/s and blower/s available at the helm but the current derives from this main panel.
This same panel should also deliver 12-volt current for “housekeeping.” It powers the 12-volt lighting system, the water pressure pump/s for the freshwater system/s and powers such appliances as the running or anchor lights.
The 120/220 volt system/s may appear in the same panel or a separate panel. If the vessel is equipped with the original factory wiring and accessory system there will generally be a single panel for all circuits. If a generator was added later or if dockside wiring was added to the vessel after delivery then the systems will vary with the installer.
Even small houseboats have a fairly complex wiring system and the larger boats have many hundreds of feet of conductor strung through the vessel. It is absolutely essential that the integrity of this wiring system be preserved and maintained in proper order.
Improper wiring in any vessel can be deadly. Even low voltage current can start a fire. High voltage circuits can start a fire or electrocute the unwary. The houseboat has a well thought out grounding system that serves to control stray current in the vessel and reduce galvanic corrosion.
Any disturbance of this system can cause damage to the propellers, rudders, shafts, and any other underwater gear. The grounding system must be maintained in good condition and any conductors or terminals which show damage should be replaced immediately.
The houseboat will employ a 3 wire system with the third wire serving the ground fault breaker. The smallest amounts of current applied to this conductor will cause the breaker to trip and interrupt the flow of current. This protects both the vessel and the boater.
It is also essential that this system never be compromised and that nothing be done to disable the operation of the ground fault breakers. If your breakers are tripping there is a reason and you should be glad that they do so. It may be a nuisance but they are trying to tell you something. Find out why they are opening the circuit and repair the problem.
Should you decide to add any appliances or additional circuits to the houseboats’ wiring system be certain to add an additional breaker to the panel and label it properly. The panel initially installed in the vessel will generally have additional spaces available for these added breakers.
Larger houseboats may have “demand” systems on the generator/s. These systems automatically start the generator/s when any 110 volt or 220 volt switch is turned on, if they are not already running. The demand generator system is only one of the many sophisticated systems employed on a modern houseboat.
Systems such as these, and many others, are easily defeated by the unwary, wannabe electrician. If you do not truly know what you are doing, leave the wiring to your mechanic. It may cost you initially but it may also save you a great deal of money over a period of time. It can save your life.
I am not going to try to tell you how to wire a houseboat in this article. First there is not room here and second you should have specialized skills before you attack the problem.
If you do intend to tackle a wiring problem, I will offer a few ideas. Always keep the wiring as near to the factory provisions as possible.
If you think you have found a flaw in the original system, consult the factory before changing it. There may be considerations of which you are not aware. Anything that you change may adversely affect something else and some changes may have disastrous results. A great deal of thought and work went into the original system.
If you do change any portion of your houseboats wiring, be certain that you record the change in the ships log and make the needed alterations to the wiring diagram. The next person who addresses the wiring system is unlikely to intuit the thinking that prompted your change.
Wiring on the houseboat is a modern marvel and it is interesting to see the system as it evolves in the factory. If you should have a chance to visit the manufacturer of your houseboat or any other you should specifically ask to see the wiring process in development. It is a real eye opener.
