Can you run an RV generator while plugged into shore power?

In this blog post, we will answer the following question: Can you run an RV generator while plugged into shore power? We will explain how an RV generator works and share with you a few safety tips for using the electrical system of your motorhome. 

Can you run an RV generator while plugged into shore power?

Yes, you can run an RV generator while plugged into shore power. We get how this may cause concern as it seems counterintuitive, but remember that RV generators are built with a transfer switch, thus all the power will come from the shore power while the generator will remain charged and risk-free. 

To better understand, you must know how an RV generator set works. We will do our best to explain it! 

An RV has a network of batteries supplying the comfort equipment with 12 V direct current or 220 V alternating current via a current converter:

  • The batteries which are recharged while driving by the motorhome motor discharge quickly as soon as the machine is used at the station without driving.
  • Starting the engine without the motorhome rolling is not sufficient to recharge the batteries, especially with the use of comfortable electrical devices such as television.
  • It is then necessary to resort to another means of electric power supply which can be the 220 V connection on a terminal of a fitted out area.

On an isolated site, the RV generator set is the easiest and most affordable way to obtain the desired amount of current on-demand.

The choice of a generator is made first by its power, which must be calculated by the consumption of the devices to be supplied, then according to criteria of weight, size and operation-specific to motorhomes and caravans.

How does the RV generator work?

The generator in an RV basically consists of an electric winding driven by an internal combustion engine, diesel, gasoline or gas, capable of producing alternating current. The type of fuel will be determined primarily by the fuel used in your vehicle’s main engine. In the case of caravans, a very popular option is those fueled by propane gas.

If you have a 30 amp electrical system in your motorhome you can basically use 3,600 watts before exceeding the capacity of the electrical system. 30 amps x 120 volts = 3,600 watts. This is why manufacturers of motorhomes with 30-amp electrical systems equip them with 4,000-watt generators. RVs with 50 amp electrical systems are equipped with larger generators.

Motorhomes with two air conditioners up to 15000 BTU can be equipped with an 8000-watt generator to supply all the consumption on board, although it is true that the dryer or the washing machine cannot be used with both breaths of air on. RVs with three air conditioners typically have a 10,000-watt generator.

How long can I use an RV generator?

The main question is often the frequency and duration of periods of electrical connections. What is my actual need for electrical energy? If you want to move around in complete autonomy for weeks on end, without giving up the comfort of television, air conditioning, Nespresso machine, etc., you will not be able to do without a photovoltaic installation, a generator or a fuel cell.

When you consider that a stand-alone power supply can quickly eat up 2,000 francs or more, there is no harm in tapping into the grid every now and then. We use our vehicle for approx. 40 days a year, with a maximum of 50% mains current, which means that we pay around 100 francs per season for ground power. For the rest, the calculation is simple.

If there is no connection to the network, the need must be covered by our 100 Ah passenger compartment battery. Since the refrigerator runs on gas, we make our coffee with an Italian coffee maker and don’t dry out hair, we can last two good nights. 

So far, we have not used a rectifier. In the spring and fall, when we happen to watch television for two hours and need more light, the situation can become critical. Even after three hours of driving, the alternator may not be able to charge the battery sufficiently.

How to connect an RV generator to a shore power

An RV generator provides a backup source of power in your home. You may connect your trailer’s generator to your home in the event of a power outage. RVs generally come equipped with a generator; the devices are also available separately at an RV store. 

RV generators typically range between 2,500 and 15,000 watts.

Here’s how to connect an RV generator to a shore power:

  1. Turn off switch boxes in both the RV and the external source.
  1. Check the RV generator for capacity in amps and wattage, the amperage should match the items you are driving. Home and RV generators include 30 amps – or 110 volts – power.
  1. Extend the RV plug at the end of your RV’s generator cord
  1. Plug in an RV generator cord adapter, an RV plug is different from outlets found in the typical home. The most common adapters are the “dog bone” and “hockey puck” adapters. Both are available in RV stores.
  1. Plug the generator into the shore power. Use a heavy-duty extension cord if connecting the generator to an indoor outlet.

Tips for the use and maintenance of your RV electrical system

The electrical system of the RV should be checked at regular intervals. Ideally, the check is done annually if you are driving a high mileage.

Keeping electrical equipment in good condition and having appliances repaired if necessary is a matter of safety. Damaged or worn electrical cables and cords should be replaced immediately.

It is well to remember not to abuse electrical devices by forcing them to work beyond their capacities … Unplug all internal devices from the caravan before connecting or disconnecting from the site power supply.

Another important tip: check the operation of the differential circuit breaker using the test button each time the caravan is connected to the power supply of a terminal. If a fuse or an earth leakage circuit breaker trips, turn off the power. Then check the cause before replacing the fuse.

Final tips

Always make sure that the power cable connected to the site is completely unwound when in use. If necessary, layout the excess cable in parallel rows next to the vehicle. Spirals or any windings should not be made. These latter practices sometimes cause the cable to overheat and it can catch fire.

An RV does not leave the cables connected to the site’s electrical network when their vehicle is not parked there. This constitutes a major security danger. For example, mowing the grass while you are away, children who may be playing with the cable, etc. Unplug the cable and wind it up next to the terminal, or just take it with you!

Please let us know if you have more questions or perhaps some suggestions about the subject. 

FAQ on Can you run an RV generator while plugged into shore power?

Can you plug an RV into a house outlet?

To plug an RV into a house outlet you will have to connect your RV to the house’s electrical system. We told you how to do it step-by-step in this article. 

Where can I plug in my RV for free?

You can plug an RV for free in community parks, churches, terminals with camping permissions and RV dealers. 

How to install an RV power supply?

The safest and simplest way to install a home connection for a recreational vehicle or RV is to use a power pedestal manufactured for this purpose. Power pedestals are similar to the hookups in most campsites, usually made with a built-in 50 amp outlet and a 30 amp outlet and one or two 20 amp outlets. 


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