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Glossary
We at Jayco know that when you are new or even experienced in RVing, there are many words that you hear a lot but may not know the meaning. If that is your situation, then you are in the right place.
A
- AC/12 DC/Propane Gas
The power sources on which RV refrigerators operate; 120 AC is 120-volt alternating current (same as in houses); 12 DC is 12-volt direct current (same as in motor vehicles); PROPANE-gas. Some RV refrigerators can operate on two of the three sources, others on all three. ↑
- Adjustable Ball Mount
A ball mount with adjustable increments allows the ball to be raised, lowered and tilted. This is needed when using equalizer bars and to help compensate for the tow vehicles weight when it is lowered onto the ball. ↑
- Anode Rod
An anode rod, when used in a water heater, attracts corrosion causing products in the water. These products attack the anode rod instead of the metal tank itself. The anode rod should be inspected yearly and changed when it is reduced to about 1/4 of its original size. The rods are used in steel water heater tanks - an aluminum tank has an inner layer of anode metal to accomplish the same thing. Anode rods should not be installed in an aluminum tank! ↑
- Axle Ratio
The ratio between the pinion and ring gears in the differential that multiply the torque provided by the engine. It is the number of drive line revolutions required to turn the axle one time. As an example, with a 4.10:1 axle the drive line turns 4.1 times for each full axle revolution. The higher the number, the more torque and thus more towing power. However, the higher the number also means less speed. ↑
B
- Backup Monitor
A camera mounted on the back of a motorhome to aid in backing up. Also can be used while driving to keep an eye on a towed vehicle. ↑
- Ball Mount
The part of the hitch system that supports the hitch ball and connects it to the trailer coupler. ↑
- Basement Storage
This is an alternate term for storage areas beneath the floor of the RV. ↑
- Battery
Battery The source of DC power for use inside an RV or for powering the DC requirements of the RV's engine and chassis in the case of motorhomes. Batteries are designed for two different applications, starting and deep cycle. The starting battery is designed to give a sudden burst of power to turn over an engine. The deep cycle battery is designed for steady low to medium amperage discharge with occasional bursts of high amperage requirements (as for running a microwave oven via an inverter. ↑
- Black Water
Waste water from the toilet system. ↑
- Blue Boy
Also known as a honey pot. Refers to a portable waste holding tank that has wheels on one end. These tanks often are manufactured out of blue plastic, hence the nickname. ↑
- Boon Docking
Also known as dry camping. Camping without electrical and water hookups. ↑
- Brake (Exterior) System - Brake Controller
A device mounted under the dash of a towing vehicle to control the braking system of the trailer. Most Brake Actuators are based on a time delay application; the longer the brakes are applied tighter the trailer brakes react. ↑
- Brake Actuator
A device mounted under the dash of a towing vehicle to control the braking system of the trailer. Most Brake Actuators a based on a time delay, the more time the tow vehicle brakes are applied the "harder" the trailer brakes are applied. ↑
- Breakaway Switch
A switch designed to activate the trailer brakes to lock up in the event the trailer becomes disconnected from the hitch while in motion. ↑
- BTU (British Thermal Unit)
A measurement of heat that is the quantity required to raise the temperature of one pound of water 1 degree F. RV air-conditioners and furnaces are BTU-rated. ↑
- Bumper Mount Hitch
A ball (with or without a bracket) attached to the bumper. ↑
C
- Camber - Wheel Alignment
Camber is the number of degrees each wheel is off of vertical. Looking from the front, tops of wheels farther apart than bottoms means "positive camber". As the load pushes the front end down, or the springs get weak, camber would go from positive to none to negative (bottoms of wheels farther apart than tops). ↑
- Castor - Wheel Alignment
The steering wheels' desire to return to center after you turn a corner. ↑
- Condensation
Condensation is a result of warn moisture laden air contacting the cold window glass. Keeping a roof vent open helps to reduce the humidity levels. Added roof vent covers help to prevent cold air from dropping down through the vent while still allowing moist air to escape. Using the roof vent fan when showering or the stove vent fan when cooking also helps prevent excess moisture buildup. ↑
- 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. ↑
D
- 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. There is now a version of stove tops that light the burners with a DSI ignition. ↑
- Dual Electrical System
RV equipped with lights, appliances which 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. ↑
- 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
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) ↑
E
- Equalizing Hitch
A hitch that utilizes spring bars that are 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. This hitch is also known as a weight distributing hitch.
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F
- Fresh (Water) Tank
The gallons of fresh water that can be stored for later use. ↑
- Full Hookup
The ability to connect to all three of the campground's facilities; electric, water and sewer. ↑
- Full-Timers -or- Full-Timing
The term used for people who live in their RV full time, or at least the vast majority of their time ↑
G
- Generator
An engine powered device fuelled by gasoline or diesel fuel, and sometimes propane, for generating 120-volt AC power. ↑
- Gray Water
Disposal water from sinks, shower. In some units, this is held in a tank separate from black water; is also dumped in tanks at campgrounds. ↑
- Gross Axle Weight Rating (GAWR)
The manufacturers maximum load weight, in pounds, that can be placed on the axle. If an axle has a 3500-lb. GAWR and the RV has two axles (tandem axles), then the RV would have a Gross Vehicle Weight Rating (GVWR) of 7000 lbs. ↑
- Gross Combined Weight Rating (GCWR)
The manufacturers maximum load weight, in pounds, allowed for the trailer and tow vehicle. This rating includes the weight of the trailer and tow vehicle plus fuel, water, propane, supplies and passengers. ↑
- Gross Trailer Weight (GTW)
Gross trailer weight is the weight of the trailer fully loaded in its actual towing condition. GTW is measured by placing the fully loaded trailer on a vehicle scale. The entire weight of the trailer should be supported on the scale. ↑
- Gross Vehicle Weight Rating (GVWR)
The manufacturers maximum load weight, in pounds, allowed for the vehicle. This rating includes the weight of the vehicle plus fuel, water, propane, supplies and passengers. ↑
H
- Heat Exchanger
A heat exchanger is a device that transfers heat from one source to another. For example, there is a heat exchanger in your 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 the blown through the ducting system for room heating. The 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 are typically 1500 watt elements (about the same wattage as an electric hair dryer) and have limited function. Basically they "take the chill off." ↑
- Hitch Weight
The amount of a trailer's weight that rests on the tow vehicle's hitch. For travel trailers this weight should be 10% to 15% of the total weight of the trailer. For fifth wheels this weight should be 15% to 20% of the total weight of the trailer. ↑
- Holding Tanks
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.
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I
- Inverter
An inverter is a device that changes 12 volt battery power to 120 volt AC power. It is used when "boon docking" (camping without hookups) to power certain 120 VAC only devices like a microwave oven. The amount of available power depends on the storage capacity of the batteries and the wattage rating of the inverter. ↑
J
K
L
- Laminate
A sandwich of structural frame members, wall paneling, insulation and exterior covering, adhesive-bonded under pressure and/or heat to form the RV's walls, floor and/or roof. ↑
- Livability Packages
Items to equip a motorhome for daily living, which may be rented at nominal cost from rental firm, rather than brought from home. Include bed linens, pillows and blankets, bath towels, pots and pans, kitchen utensils, cutlery. ↑
M
- Motorcoach
A motorhome that is built on a bus-type chassis. ↑
N
- Net Cargo Carrying Capacity (NCC) Or Payload Capacity
Sometimes called the payload capacity, this is the maximum weight of fuel, water, propane, supplies and passengers that can be added to an RV without exceeding the Gross Vehicle Weight Rating (GVWR). ↑
O
P
- Part-Timers
The term used for people who use their RV more than usual (more than just a few weekend trips a year), but who still use it less than full time. ↑
- Pilot
A pilot is a small standby flame that is used to light the main burner of a propane fired appliance when the thermostat calls for heat. Pilots can be used in furnaces, water heaters, refrigerators, ovens and stove tops. ↑
- Popup Or Pop-Up
Another name for a folding camping trailer. ↑
- Porpoising
A term used to define the up and down motion in an RV while traveling ↑
- Propane
LPG, or liquefied petroleum gas, used in RVs for heating, cooking and refrigeration. Also called bottle gas, for manner in which it is sold and stored. This is the proper term in the RV industry when referring to "LP Gas." ↑
- Pull Through
A camping site that allows you to pull through while setting up and leaving the area. A site where you do not have to back in or out. ↑
Q
R
- Roof Air Conditioning
Air conditioning unit mounted on roof of RV, to cool the RV when it is parked. When moving, most RVs are cooled by separate air conditioning units which are components of the engine, or they may be cooled by a roof top if a proper size generator is installed. ↑
S
- Self-Contained
RV which needs no external electrical, drain or water hookup. Thus, it can park overnight anywhere. Of course, self-contained units can also hook up to facilities when at campgrounds. ↑
T
- Thermocouple
A thermocouple is 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. ↑
- Tip-Out
The term used for an area or room in an RV that tips out for additional living space. The Tip-Out was generally used in older RVs. Newer RVs mainly use a slide-out. ↑
- Toad
A "toad" is an RVers term referring to a vehicle that is towed behind a motor home. Some vehicles can be towed without any modifications - others cannot be towed at all, or at least without extensive alterations. For more information on this subject: Towing World ↑
- Toe - Wheel Alignment
Toe is the measure of whether the front of the wheels (looking down from the top) are closer (toe-in) or farther (toe-out) than the back of the wheels. ↑
- Tongue Weight
Tongue weight (TW) is the downward force exerted on the hitch ball by the trailer coupler. In most cases, it is about 10 to 15 percent of GTW. TW of up to 300 lbs. can be measured on a household scale by resting the trailer coupler on the scale and placing the scale on a box so that the coupler is at its normal towing height. The trailer must be fully loaded and level.
For heavier tongue weights, place a household scale and a brick that's as thick as the scale three feet apart. Set a length of pipe on each and rest a beam across the pipes. Re-zero the scale to correct for the weight of the beam and pipe. Securely block the trailer wheels. Rest the trailer jack on the beam, one (1) foot from the pipe on the brick and two (2) feet from the pipe on the scale.
To obtain the TW, multiply the scale reading by three (3). For greater tongue weights, place the scale and brick four (4) feet apart, rest the jack on the beam three (3) feet from the scale and multiply the scale reading by four (4).
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U
- Underbelly
The RV's under-floor surface, which is protected by a weatherproofed material. ↑
- Unloaded Vehicle Weight (UVW) Or Dry Weight
Sometimes called the Dry Weight, it is the weight of the RV without adding fuel, water, propane, supplies and passengers. The manufacturers UVW will not include any dealer-installed options. ↑
V
W
- Waste Water Tanks
The gray water tank holds the waste water from the sinks and showers. The black water tank holds the waste from the toilet. ↑
- Weights - What Weighs What?
-Propane weighs 4.25 pounds per gallon
-Water weighs 8.3 pounds per gallon
-Gasoline weighs 6.3 pounds per gallon
-Diesel fuel weighs 6.6 pounds per gallon ↑
- Wet Weight
The weight of the vehicle with the fuel, freshwater and propane tanks full. ↑
X
Y
Z
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