120AC 12DC -The power sources on which RV refrigerators operate.... 120 AC means 120-volt alternating current (same as in houses); 12 DC means 12-volt direct current (same as in automobiles). Some RV appliances can operate on either electricity source and/or LP-gas (see below).
Black water - disposal water from toilet system, held in holding tank until you dump it, in large tanks or dumping station available at most campgrounds.
Boondocking - Camping without hookups. The term is also used among campers who like to enjoy all of nature, regardless of the terrain while avoiding redundant commercial campground fees.
Brake controller - A control unit mounted inside your RV that allows electric trailer brakes to become activated in harmony with the braking of the tow vehicle. This device can be used to adjust trailer brake intensity, or to manually activate the trailer brakes.
Breakaway switch - A safety device that activates the trailer brakes in the event the trailer becomes accidentally disconnected from the hitch while traveling.
Class A motorhome - An RV with the living accommodations built on or as an integral part of a self-propelled motor vehicle. Models range from 24 to 40 feet long.
Class B motorhome - Also known as a camping van conversion. These RVs are built within the dimensions of a van, but with a raised roof to provide additional headroom. Basic living accommodations inside are ideal for short vacations or weekend trips. Models usually range from 16 to 21 feet.
Class C motorhome - An RV with the living accommodations built on a cutaway van chassis. A full-size bed in the "cabover" section allows for ample seating, galley and bathroom facilities in the coach. Also called a "mini-motorhome" or "mini." Lengths range from approximately 16 to 32 feet.
Condensation - Condensation is a result of warm moisture laden air contacting a cold window glass. In an RV, keeping a roof vent open helps to reduce the humidity levels especially when using the shower of the stove.
Converter - A converter is device that converts 120 volt A/C (alternating current) to 12 volt DC (direct current). The RV devices mostly run on 12 volt DC power that is supplied by the battery, which allows the RV to function independently. When "shore power" (an electrical supply) is available, the converter changes the voltage from 120 to 12 volt to supply the appliances and to recharge the battery.
Curb Weight (CW) - Also known as Net Weight. The weight of the RV as it is sitting on the lot, without the personal load you will be adding.
Dinette - booth-like dining area. The table usually drops to convert the dinette into a bed at night.
Dinghy - A vehicle towed behind a motorhome, sometimes with two wheels on a special trailer called a tow dolly, but often with all four wheels on the ground.
Dry Weight (DW) - The weight of the RV without adding fuel, water, propane, supplies and passengers. The manufacturers UVW will not include any dealer-installed options. Also known as Unloaded Vehicle Weight.
DSI ignition - Direct Spark Ignition. This term refers to the method of igniting the main burner on a propane fired appliance. The burner is lit with an electric spark and the flame is monitored by an electronic circuit board. This ignition system is used in refrigerators, furnaces and water heaters.
Ducted AC - Air conditioning supplied through a ducting system in the ceiling. This supplies cooling air at various vents located throughout the RV.
Ducted heat - is warm air from the furnace supplied to various locations in the RV through a ducting system located in the floor (similar to house heating systems).
Dual electrical system - RV equipped with lights, appliances that operate on 12-volt battery power when self-contained, and with a converter, on 110 AC current when in campgrounds or with an onboard generator.
Engine oil cooler - A heat exchanger, similar to a small radiator, through which engine oil passes and is cooled by airflow.
Fan Switch - A normally open switch that closes at a preset temperature. It causes the furnace to run for a short time after the thermostat opens, allowing the furnace to cool down.
Fifth-wheel trailers - Fifth-wheel trailers are trailers designed to be coupled to a special hitch that is mounted over the rear axle in the bed of a pickup truck. These trailers can have one, two or three axles and are the largest type of trailer built. Because of their special hitch requirements, fifth-wheel trailers can only be towed by trucks or specialized vehicles prepared for fifth-wheel trailer compatibility.
Furnace Ignition Control Board - When powered, initiates gas valve opening and spark sequence which lasts approximately 7 seconds. Newer boards are 3 try (ie. will attempt to ignite 3 times at approximately 60 second intervals). Older models are 1 try.
Gas Pressure - LP gas pressure must be 11" of water column (6.25 oz per sq. in.). A manometer is required to check and adjust the pressure.
Gross Axle Weight (GAW) - The total weight supported by each vehicle's axle (front or rear). To obtain this number, you have to weigh the vehicle and the trailer on a scale.
Gross Axle Weight Rating (GAWR) - The manufacturer's rating for the maximum allowable weight that an axle is designed to carry. GAWR applies to tow vehicle, trailer, fifth-wheel and motorhome axles.
Gross Combined Weight (GCW) - The actual weight of a vehicle and trailer combined. To obtain this number, you have to weigh the vehicle and the trailer together on a scale.
Gross Combination Weight Rating (GCWR) - The maximum allowable weight of the combination of tow vehicle and trailer/fifth-wheel, or motorhome and dinghy. It includes the weight of the vehicle, trailer/fifth-wheel (or dinghy), cargo, passengers and a full load of fluids (fresh water, propane, fuel, etc.).
Gross Vehicle Weight (GVW) - The actual weight of a vehicle when fully loaded. (Base Curb Weight + Cargo Weight)
Gross Vehicle Weight Rating (GVWR) - The total allowable weight of a vehicle, including passengers, cargo, fluids and hitch weight.
Generator - An engine powered device fuelled by gasoline, diesel fuel or propane for generating 120-volt AC power.
Grey water - disposal water from the sinks and the shower. In some units, this is held in a tank separate from black water. As with Black water, it is dumped in large tanks or dumping station available at most campgrounds.
Heat exchanger - A heat exchanger is a device that transfers heat from one source to another. In a furnace, the propane flame and combustion products are contained inside the heat exchanger that is sealed from the inside area. Inside air is blown over the surface of the exchanger, where it is warmed and then blown through the ducting system for room heating. Combustion gases are vented to the outside air.
Heat strip - A heat strip is an electric heating element located in the air conditioning system with the warm air distributed by the air conditioner fan and ducting system. They typically have 1500 watt elements (about the same wattage as an electric hair dryer).
Holding tanks - Tanks that hold water. There are three different holding tanks on most RVs; fresh water tank, gray water tank and black water tank. The fresh water tank holds fresh water that can be stored for later use. The gray water tank holds the waste water from the sinks and showers. The black water tank holds the waste from the toilet.
Hookups - Connections to a campground's facilities. The major types of hookups are electrical, water and sewer. Hookups may also include telephone and cable TV in some campgrounds. Full hookups refer to a combination of water, electricity and sewer.
Igniter Electrode - Similar to a spark plug. There are two versions; a three 3 probe (remote sense) and a 2 probe (local sense).
Inverter - An inverter is a device that changes 12 volt battery power to 120 volt AC power. The amount of available power depends on the storage capacity of the batteries and the wattage rating of the inverter.
Laminate - A sandwich of structural frame members, wall paneling, insulation and exterior covering that is adhesive-bonded under pressure and heat to form an RV's walls, floor and roof.
Light Weight RV - RVs that are designed to be easily towed behind most Minivans, light-duty trucks and cars! The most common being a pop-up trailer.
Limit Switch - A furnace safety switch that is normally closed but that opens if it gets to hot. When it opens, it turns off the power to the gas valve and igniter board.
LP gas - Liquefied Petroleum gas, either propane or butane. Propane fuels RV appliances, such as the stove and refrigerator.
Maximum Loaded Trailer Weight - The maximum allowable fully loaded weight of a trailer. (GCWR - GVW).
Net Carrying Capacity (NCC) - The amount of cargo, passenger and fluid weight that can be added to an RV without exceeding its GVWR. The NCC label in an RV may not include the weight of dealer installed or factory installed options already on the vehicle. Subtract UVW from the GVWR and the result is what can be added to the factory weight.
Pilot - A pilot is a small stand-by flame that is used to light the main burner of a propane fired appliance when the thermostat calls for heat. Pilots are common in furnaces, water heaters, refrigerators, ovens and stove tops.
Pop-up Trailer - Also known as a folding trailer, great for first timers due to its simplicity and relatively low cost.
Propane - LPG or liquefied petroleum gas. Used in RVs for heating, cooking and refrigeration.
Roof air conditioning - An air conditioning unit usually mounted on the roof of an RV to "cool off" the inside of the RV when it is parked. When moving, most RVs are cooled by separate air conditioning units that are components of the engine. Some can be cooled by a roof top if a proper size generator is installed.
RV - Recreational Vehicle is a motorized or towable vehicle that combines transportation and temporary living accommodations for travel, recreation and camping. RVs come in all shape and sizes for any budget or need. They range from camping trailers costing a few thousand dollars to luxurious motorhomes with prices well into six figures. RVs refer to multiple RV and RVers refer to their owners.
Safety chains - A set of chains that are attached to the trailer A-frame and connected to the tow vehicle while towing. Safety chains are intended to keep the trailer attached to the tow vehicle in the event of hitch failure, preventing the trailer from complete separation. They should be installed using an X-pattern (criss-crossed) so the coupler is held off the road in the event of a separation.
Self contained - An RV which needs no external electrical, drain or water hookup. A self contained unit can park overnight anywhere.
Thermocouple - A device that monitors the pilot flame of a pilot model propane appliance. If the pilot flame is extinguished, the thermocouple causes the gas valve to shut off the flow of gas to both the pilot flame and the main burner thus preventing major disasters.
Tongue Weight (TW) - The amount of weight imposed on the hitch when the trailer is coupled. Also referred to as "hitch weight". Tongue weight for a travel trailer can be 10-15 percent of overall weight; fifth-wheel hitch weight is usually 18-20 percent of the overall weight.
Tow bar - A device used for connecting a dinghy vehicle to the motorhome when it's towed with all four wheels on the ground.
Trailer brakes - Brakes that are built into the trailer axle systems and are activated either by electric impulse or by a surge mechanism. The overwhelming majority of RVs utilize electric trailer brakes that are actuated when the tow vehicle's brakes are operated, or when a brake controller is manually activated. Surge brakes utilize a mechanism positioned at the coupler that detects when the tow vehicle is slowing or stopping and activates the trailer brakes via a hydraulic system.
Transmission cooler - A heat exchanger similar to a small radiator through which automatic transmission fluid passes and is cooled by airflow.
Travel trailer - Also referred to as "conventional trailers" these types of trailers have an A-frame and coupler and are attached to a ball mount on the tow vehicle. Travel trailers are available with one, two or three axles.
Umbilical cord - The wiring harness that connects the tow vehicle to the trailer, supplying electricity to the trailer's clearance and brake lights, electric brakes and a 12-volt DC power line (to charge the trailer's batteries).
Underbelly - The RV's "underfloor" surface that is protected by a weatherproofed material.
Unloaded Vehicle Weight (UVW) - The weight of the RV without adding fuel, water, propane, supplies and passengers. The manufacturers UVW will not include any dealer-installed options. Also known as Dry Weight.
Van Conversion - A fully loaded van and the smallest of the fully enclosed motorhomes. These are constructed on a van chassis with elevated roof lines but no modifications to the length or width of the original chassis. Gross vehicle weights are in the 6000 to 8000 range with heights of 7 to 8 feet and lengths of 17 to 19 feet.
Weight carrying hitch - Also known as a "dead-weight" hitch, this category includes any system that accepts the entire hitch weight of the trailer. In the strictest sense, even a weight-distributing hitch can act as a load-carrying hitch if the spring bars are not installed and placed under tension.
Weight distributing hitch - Also known as an "equalizing" hitch, this category includes hitch systems that utilize spring bars that can be placed under tension to distribute a portion of the trailer's hitch weight to the tow vehicle's front axle and the trailer's axles.
Wet weight - The weight of the vehicle with the fuel, freshwater and propane tanks full.
Wheelbase - The distance between the center lines of the primary axles of a vehicle. If a motorhome includes a "tag" axle, the distance is measured from the front axle to the center point between the drive and "tag" axle.
Wheelbase - Distance between center lines of the primary axles of a vehicle. If a motorhome includes a tag axle, the distance is measured from the front axle to the center point between the drive and tag axles.
Yaw - Refers to the "fish-tailing" action of a trailer caused by external forces that set the trailer's mass into a lateral (side-to-side) motion. The trailer's wheels serve as the axis or pivot point. Also known as "sway".