Appliance amperage
requirements
Watts = Volts X amps
Each of our electrical
appliances in our motorhomes uses a particular amount of electricity. Our Motorhome electrical systems can carry
only so much electricity. Rexhalls come in two sizes,
30 amps and 50 amps.
If we try to use more
electrical appliances than our RV is designed to handle, something will blow
(fuse or circuit breaker). Damage to
appliances may also occur.
So it is helpful to have a
list of how many amps or watts each of the electrical appliances in your RV
demands. Although this information is
usually somewhere on the appliance, it is often not easy to find. And although there are lists available in a
number of books, I have found it helpful to have them written down so I can
refer to them easily. Some RVers post
them inside a kitchen cabinet or near their electrical monitor panel for quick
reference before turning on that extra appliance.
Also keep in mind that if
you have a 50 amp RV and you are plugged into a 30 amp campground, you can only
use 30 amps at any one time.
Most motor driven electrical
appliances, as typified by an air conditioner, may require two or three times
as much power (watts or amps) to start up than they do to run once they are
going.
Also remember that if you
are using an extension cord, the bigger and shorter the better. The most common use of an extension cord is
when we plug in at home or when staying at a friend or relative’s home. A 12 gage wire extension cord is about as
small as you should go, and a 10 gage is better. The dilemma is how long to have the cord, and
although shorter is better from a power standpoint, practicality usually
dictates a cord long enough to reach the majority of our uses. Mine is 100 feet. Don’t forget that household plugs carry only
15 amps.
120 Volt AC power
Appliance Amps
Air conditioner 13
Coffee maker 12
Water heater (electric) 12
Washer/dryer 13
Microwave 8
Convection 15
Refrigerator 3.5
Converter (charging) 8
Space heater (1600 watts) 13
Space heater (800 watts) 6.5
Iron 8
Electric blanket 2
Hair dryer (1500 watts) 13
Hair dryer (400 watts) 3.5
Curling iron 0.7
TV .5-1.0
VCR 0.2
Computer 2
12 Volts DC power
Appliance Amps
Lights 0.5-1.5
Basement light 0.5
Porch light 1.5
Bathroom light 4
Dinette light 6
Vent fan 1
Fantastic fan 3
Furnace fan 7-9
Water pump 5
When we are plugged in to
shore power, part of the 120 volt electricity goes directly to running our
appliances (air conditioner, microwave, electric outlet plugs, etc). The other part of the 120 volt current goes into
the converter, which converts it to 12 volt DC electricity. The converter uses some electricity (amps) to
make this change, and send part of the resulting 12 volts to recharge the house
batteries and part of the 12 volt current to run the 12 volt “appliances”.
These include lights,
various fans, water pump if turned on, a number of monitoring panels and
devices and anything else that runs off the house batteries.
The Rexhall Club website has
a technical section which includes the Rexhall Company Newsletter of Winter
2001 which presents some of the above information. If you are interested you might want to look
at it.
Remember, if you can find
the wattage on an appliance, divide by 120 (volts) to get the amperes.
Keep in mind that the secret
to all this is to turn off one big power user before turning on another big
power user. Some campers post this list
so they can check before turning on another appliance.
Doug