10
hoUSe electrIcal - IntroDUctIon
This section contains guidelines, procedures and information that assist in understanding the electrical system
and the operation of various components. Refer to the OEM manuals included in the Owner’s Information File
box for their respective, in-depth, individual component operating instructions. Due to variations in options and
floor plans, some items and materials discussed in this section will not apply to all motorhomes.
General Overview:
The motorhome can utilize various sources of electrical power: shore power, generator, chassis batteries and
house batteries. All of these electrical power sources, while independent of each other, can be combined in a
variety of ways to provide a highly efficient electrical operating system. For the motorhome with 30 Amp shore
power two types of electrical systems are used: 120 Volt AC and 12 Volt DC. For the motorhome with 50 Amp
shore power two types of electrical systems are used: 120/240 Volt AC and 12 Volt DC.
Shore power is the most efficient and should be used whenever possible. The generator can be used when shore
power is unavailable. Two different sources supply the main AC circuit breaker panel with power: the shore
power cord or the on-board generator. The AC power source used is automatically selected by a switching device
known as a transfer switch.
WARNING:
The electrical system is engineered and tested for safety. Circuit breakers and fuses protect the
electrical circuits from overloading. When planning modifications or additions to the electrical
system, ensure safety of the electrical system. Please note that any modifications may void the
warranty.
WARNING:
Water is electrically conductive. DO NOT use any electrically powered item or outlet that may be
exposed to a water source. Such use can result in a serious shock causing injury or death.
The motorhome has two 12 Volt DC systems: chassis and house. These two systems, for the most part, are
separate from one another. The house system does not operate engine functions; the engine system does not
operate house functions. However, within the two systems there are some inner connections.
For example:
While the motorhome is driven, the alternator maintains the charge on the house batteries. Likewise, while the
motorhome is plugged into shore power, or the generator is running, the engine batteries are being charged. Each
system will supply 12 Volt DC power to the 12 Volt DC distribution panels.
The chassis and house systems have their own sets of batteries. The chassis batteries supply 12 Volt DC power
to the front distribution panel located outside in the front roadside bay. This panel contains mostly engine system
circuits and wiring such as headlights, taillight, dashboard functions, gauges, etc. The house batteries supply 12
Volt DC power to the load center 12 Volt DC fuses. These fuses are for the house interior lighting and appliances.
Become familiar with these fuses and the items they operate.
With all the technological advancements taking place in the past several years, manufacturers have now
incorporated electronics into these systems. It is important to keep the 12 Volt DC systems in good working order.
These systems, with their incorporated electronics, are voltage sensitive. Some items can be damaged if the DC
voltage is not maintained within the designed specifications.
A majority of the lighting and appliances are designed to operate from 12 Volt DC (direct current) power.
This is why the batteries play such an important role in the function of the motorhome. There are exceptions
with appliances such as the microwave or television; however, indirectly they still operate from 12 Volt DC
power as they can be operated from the inverter. The chassis functions (engine, transmission, dash air, etc.) are
also 12 Volt DC.
Shore Power:
The motorhome is equipped with a shore power cord to connect the motorhome to outside electrical services.
Shore power service is the most efficient source of electrical power. The plug end of the shore power cord is 50
Amp, 240 Volt AC. When this type of power service is not available, electrical adapters are required to allow a
proper and safe connection to the electrical service supply.