AC Electrical Amperage Draw

Electrical appliances consume power, measured in amps. When your RV is connected to shore power, that connection will make a specified amount of power available and if you exceed that amount, a circuit breaker trips and you are left in the dark.

The key to keeping the lights on is managing your electrical power consumption and to do that you must be aware of your amperage consumption.

RVs have two electrical systems; a 12-volt DC and 120-volt AC. This article is about 120-volt AC power.

30-amp Power Supply

Excessive power draw, leading to failure, is predominantly experienced with RVs is connected to a 30-amp power supply. When more than a 30-amp demand is placed on the system, a circuit breaker in the RV or the power supply line will trip, disconnecting the power.

RVs are designed with either 30-amp or 50-amp electrical systems. As 50-amp systems, connected to a 50-amp power source, encounter excess power draw far less frequently, we'll concentrate on 30 and 50-amp RVs connected to a 30-amp power source. Without this safeguard, the system could be overloaded resulting in a fire and/or damaged electrical components.

This can usually be rectified by reducing your power draw and re-enabling the circuit breaker. A better solution is to be cognizant of your power consumption and maintain your power draw to less than 30-amps.

Know Your Amps

There are different levels of awareness regarding amperage use in your RV. The easiest, but unfortunately also the least accurate, is to reference a generic amperage approximation chart. Charts, such as the listing below, show the approximate amperage draw of common RV appliances. Keep in mind, your appliances may draw more or less.

I created an Amperage Draw Chart for a project and I thought it might be of interest to members. Feel free to copy it and print a hard copy to carry in your RV or save it to your smartphone.

Amperage Draw Chart

Appliance Amps

air conditioner (starting) 16 - 18

air conditioner (running) 13 - 16

absorption fridge 5 - 8

blender 5 - 15

blow dryer 7.5 - 13

charger (small electronic) 0.5 - 2

coffee maker 5 - 15

converter (charging) 6 - 8

curling iron 4 - 10

crockpot 2 - 5

dryer 12

electric blanket 4.2

Appliance Amps

electric kettle 5 - 15

electric frying pan or grill 8 - 15

electric water heater 10 - 15

induction cooktop 10 - 15

lights (per bulb) 0.5 - 1.5

iron 8 - 13

laptop computer 1.5 - 3

microwave oven 10 - 13

microwave/convection oven 7 - 15

printer 0.5 - .07

residential fridge (21 cu ft) 10

roof fan 3 - 5

Appliance Amps

furnace fan 7 - 10

space heater (800 watt) 4 - 10

space heater (1600 watt) 7 - 13

television 1.5 - 4

toaster 7 - 13

toaster oven 10 - 13

satellite receiver 0.5 - 1

vacuum cleaner 2 - 6

water heater (heating) 8 - 13

washing machine 4

washer/dryer combo 11

Calculating Amps

Appliances list their electrical specifications. The maximum power requirement for each device is imprinted into the device or a label affixed to it. You can use this to calculate its maximum amperage draw.

Some appliances list their power requirements in amps and others specify this value in watts and volts, which can be converted into amps using the following formula.

watts ÷ volts = amps

To demonstrate this I'll use our Ninja Foodi 5 in 1Grill/Air Frier. Its label specifies "120 V ~ 60 Hz 1760W". Let's do the math.

1760W ÷ 120V = 14.67 amps

This indicates the maximum amperage consumed by this device is 14.67.

As is the case with many electrical devices, their power requirement fluctuates during use. many items require maximum power initially and then less during ongoing use. The next measurement method addresses real-world consumption.

Monitoring Amps

Inexpensive electronic meters are available to measure electric load in real-time, while a device is in operation.

A "Kill A Watt" meter or similar devices measures electrical consumption in several ways, including the amperage. They cost a modest $20 to $45 (US) and they are as easy to use as plugging it in and pressing a button.

The metering device plugs directly into your wall outlet and your device plugs into its electrical receptor. It then measures any draw going through the device. This allows you to observe the initial power draw and typical draw while in operation.

Hidden Amperage Draw

The above enables you to be aware of the power being drawn by your electrical appliances. There are other systems and devices in your RV that may also be drawing amps without your knowledge. An inverter/converter, battery charger and more can also draw power unbeknownst to you. Some items, such as a battery charger can place a considerable load on your power supply.

These are items you must be aware of and considered when managing a limited power supply. Some systems empower you to turn some of these off to provide greater control over power usage.

Automated Amps Management

Some RVs automate the power management task. An example of this is the Magnum Energy system in our motorhome.

Our motorhome has a 50-amp power system but also provided a 30-amp power setting for occasions when we must step down our power for a 30-amp supply. With this setting enabled, it will shut down power to certain outlets and devices to maintain a consumption level of less than 30-amps.

You'll have to check your Owner's Manual to determine if your RV has this capability.

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