Wednesday, December 26, 2007

Protecting Your RV's Electrical Systems

Sponsored by Jody's RV in Greenwood, SC

Visit us at www.jodysrv.com1425 Hwy 72/221 East,  Greenwood, SC  29649 Call us at (864) 227-6500 or email me at

Managing Your Electrical Needs

RV electrical systems come in a variety of configurations and may be sized differently based upon their intended use. For example, most small to medium sized recreational vehicles incorporate 30 amp circuitry, which is sufficient to operate the rooftop air conditioner and some fairly small appliances. Larger, more elaborate units may be wired for 50 amp service if the vehicle uses multiple rooftop air conditioners or is equipped with a washer/dryer set up.

However, the electrical systems found in most "casual use" RV's share one distinct commonality ... they are ALL wired for 110 volt, single phase power sources. Because the 30 amp three-pin angled and 50 amp four-pin offset plug configurations found on most campers look similar to those on the old dryer outlet at home, many novice RVers assume that these units require 220 volt service. Obviously, this can be an extremely costly mistake, in some cases requiring a complete re-wire of the unit and replacement of some or all of the appliances and electronic systems. Always make certain that your RV is connected to a 110 volt, 30 or 50 amp power supply as per the manufacturer's specifications. Heavy appliance wiring in the home such as clothes dryers, stoves, etc., are usually wired to a 220 volt service and, though the outlets look similar to the shore line plug on your camper, will seriously damage your systems.

"Why do my breakers keep tripping?"

Another common misconception among inexperienced RVers is the notion that RV electrical systems perform to the same level as those in the home. We field questions ranging from 'Why do my breakers keep tripping?' to 'Why did my shore line plug melt?' on an almost weekly basis. Electrical systems in the home are wired and sized specifically to meet the power needs of the home. The operative word here is "sized". Most home electrical power supply lines are fed by 200 amp or higher panel capacity and is expandable as greater load is required. As a result, virtually all appliances in a home environment may be operated simultaneously with little or no interruption of service.

RV systems, on the other hand, are limited to ONLY 30 or 50 amps of incoming power. A bit of simple math will reveal the problems that can result from overloading these systems. The following example, which assumes a unit with 30 amps of electrical service and many of the standard appliances demonstrates the underlying causes of these problems.

The13,500 BTU - Roof top Air Conditioner draws around 16.9 amps when the compressor is on. Likewise, the amperage draw on an electric water heater averages 7 - 9 amps, the refrigerator compressor averages 7-10 amps and a 1000 watt microwave draws 8.33 amps. Given that all of these appliances are being used simultaneously, the total amperage draw is 39.23 and that's without the TV, hair dryer, 12 volt converter, lights, etc. Per the example, we ONLY have 30 amps of incoming power supply, yet we're drawing 39.23 total amps. This equates to a low voltage situation and low voltage translates to heat. Heat buildup is what triggers circuit breakers to trip folks and it's going to happen in this situation!

The moral of this story is, don't overload your power supply!!! It not only damages your on board systems, it is a potentially dangerous situation since the possibility of fire is present. Don't operate heavy amp draw appliances simultaneously such as the microwave and air conditioner. Also, changing the water heater over to gas operation will also help to reduce the load and stop worrying ... you won't blow the camping budget on propane gas just because you heat your water with it! Besides, gas water heaters recover faster and provide hotter water than electrical systems anyway.

One final piece of advice ... Even though you own a nifty little adapter, which allows you to plug your RV shore line into a standard "house-type" outlet, you need to keep in mind that these outlets typically deliver only 15 to 20 amps. Obviously, the math gets even more critical here, since 15 amps is not even sufficient to meet the needs of the air conditioner!! Oh and one more thing ... excessively long drop cords, especially undersized ones add to the resistance load to your unit and just like low voltage, resistance equals heat!! Don't run your air conditioner or other heavy draw appliances unless you're connected to a full 30 or 50 amp power supply!!

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