A portion of this post was provided by RV LIFE Technical Reviewer Steve Hericks.
Avoid Having To Deal With A Space Heater Fire In Your RV
Using a space heater can be a great way to keep your RV warm and toasty on cold winter days. While your RV’s propane furnace will meet most of your heating needs, a space heater can quickly provide heat where you need it. The problem is, space heaters can cause (sometimes fatal) RV fires when we aren’t careful with them.
The National Fire Protection Association (NFPA) reported that 9 out of 10 fire-related deaths involved the use of mounted or fixed electric space heaters. According to the report, space heaters were the leading cause of catastrophic fires in the US.
That being said, space heater fires in RVs are usually far more devastating than home fires due to their multitude of highly flammable components. The chances of you losing your life in an RV fire are far greater than losing your life in a house fire.
Have a fire escape and a fire extinguisher on hand
There are more than 2,000 RV fires each year. It makes good sense to be well prepared in case you are ever faced with this nightmare in your RV.
For instance, it’s a good idea to have a fire escape plan and practice your fire escape route before you need to use it. And don’t be shy about sharing it with everyone who stays or travels with you in the RV. Everyone in the RV should be familiar with the fire escape plan and routes.
You should also have a fire extinguisher within easy reach at all times. While most RVs come with a single fire extinguisher, having an extinguisher within easy reach at all times requires a minimum of three fire extinguishers, depending on the size of your RV.
Inside the RV, you should have a fire extinguisher in the kitchen and one in the sleeping area. Outside, you should have a fire extinguisher in an unlocked compartment and/or one in the tow vehicle.
While electric space heaters can be used safely in RVs, warming up an RV with a space heater requires more caution than using a space heater in a sticks-and-bricks home. This is due to both the limited size of the RV and the limited electrical supply in an RV.
Living within the Capacity of an RV’s Receptacle Branch Circuit
Operating 120-volt plug-connected equipment in an RV shares similarities with a home but with notable differences due to the RV’s limited capacity. This reduced capacity increases the likelihood of overloading the system. Smaller RVs typically have a single 15A/1800W circuit, unlike homes which usually have multiple 20A/2400W circuits. With multiple receptacles on each RV circuit, it’s easy to connect enough loads to cause an overload.
Understanding Circuit Breaker Limitations
It’s crucial not to rely solely on a circuit breaker to prevent damage or fire. Circuit breakers are designed to withstand brief overloads, such as those caused by motor startups. This means they may not trip immediately even when the circuit is slightly overloaded, allowing the circuit to function under these conditions for extended periods. A well-functioning 15A breaker, for instance, won’t trip when loaded at 15A and can operate at 19.5A (130%) for up to an hour without tripping.
Risks of an Overloaded Circuit
An overloaded circuit can cause breakers and wiring to overheat. Loose connections may become hot enough to char wire insulation and melt receptacles or plugs, presenting significant safety hazards.
Managing Loads to Prevent Overloading
To avoid overloading a receptacle branch circuit, it’s essential to be aware of and manage the loads that are operating simultaneously. “Operating” refers to devices that are turned on, not just plugged in. Some devices, like wall transformers, do not have a power switch and are operational whenever plugged in.
It’s generally understood that a 15A receptacle branch circuit should not operate more than 15A of combined continuous and intermittent duty loads. “Continuous duty” loads are those that run for more than 3 hours in a 24-hour period, like space heaters, portable A/C units, and fans that typically operate all day. “Intermittent duty” loads, such as lights or kitchen appliances, run for less than 3 hours in 24. Furthermore, a 15A circuit should be limited to no more than 12A (80%) of continuous duty loads.
Understanding ‘Rated’ Power vs. Actual Draw
The ‘rated’ power of loads often differs from their normal operational draw. It typically represents the maximum draw under less-than-ideal conditions (like high demand or low campground voltage). For those serious about safely maximizing their RV’s power system, measuring each device’s running load with tools like a ‘Kill-a-watt’ meter is crucial.
Guidelines for Managing Loads on an RV’s Receptacle Branch Circuit
To effectively manage and operate loads on the same receptacle branch circuit in an RV, follow these steps:
- Identify the Circuit’s Operating Capacity:
- Determine the receptacle branch circuit’s capacity in amps, which is indicated on its breaker.
- If you are uncertain about which sockets correspond to which breaker, conduct a simple test. Turn on only one breaker at a time and plug a device like a light into various sockets to identify which ones are powered by that specific breaker. Repeat this process for each outlet breaker in your RV’s breaker panel. This will give you a clear understanding of which outlets are connected to which breakers.
- Calculate Individual Load:
- Ascertain the load in amps for each device. This information can usually be found on the device’s data plate or through measurement.
- Classify Load Duty:
- Classify each load based on its intended use – either continuous or intermittent duty.
- Add the Loads Appropriately:
- Ensure the combined loads do not exceed 15A, with continuous duty loads not surpassing 12A.
- Example 1 – Space Heater:
- Rated Power: 1500W
- Data Plate Reading: 12A
- Load Class: Continuous duty
- Analysis: This heater uses the circuit’s entire continuous duty capacity of 12A. The remaining 3A capacity can accommodate up to 3A of intermittent loads, such as lights or small appliances.
- Example 2 – Blow Dryer:
- Rated Power: 1800W
- Data Plate Reading: 15A (on high heat & fan)
- Load Class: Intermittent duty
- Analysis: This dryer alone occupies the entire 15A circuit. No other loads should be used concurrently, especially on high settings. If used on lower settings, measure its running load to reassess concurrent use.
- Example 3 – Portable A/C and Fan:
- Devices: Portable 9kBTU A/C (12A) and Fan (3A)
- Load Class: Both continuous duty
- Analysis: Combined, they exceed the 12A limit for continuous loads. However, real-world power draw might differ. The fan’s rating is for its highest speed, which might not be necessary, and the A/C’s actual running draw could be lower (7-9A). Though breakers can handle overcurrent during motor start-ups, it’s vital to measure each device’s running current separately. If their combined continuous duty current is under 12A, test the setup by connecting both to the circuit. Check if the A/C starts multiple times without tripping the breaker. If successful, this configuration is viable.
Additional Space Heater Fire Safety Tips
Here are some additional fire safety tips to prevent having to deal with a space heater fire in your RV.
- Be sure to buy a heater that has a seal from Underwriters Laboratories. Look for the UL seal on the space heater you are considering.
- Get a heater with a thermostat and overheat protection.
- Be sure to choose a space heater that has an auto shut-off feature, so it turns itself off if it gets too hot or tips over.
- Keep the space heater at least three feet away from any object or material that could possibly burn. Remember, the electric fireplaces that many RVs come with now are actually just decorative space heaters. Don’t put dog beds or other flammable objects next to them.
- Only use space heaters on a solid, flat, non-carpeted surface.
- Keep space heaters out of the way in places where they won’t get tripped over.
- Space heaters should only be used when you are present and awake. Never leave a space heater plugged in when you go to sleep or leave the RV.
- Always keep children, pets, and their toys away from space heaters.
- Never plug a space heater into an extension cord or power strip.
- When you are using a space heater, frequently check the power cord and plug for heat. If the cord or plug seems warm, unplug it immediately.
Get tips from other RVers
Forums such as iRV2.com and blog sites like RV LIFE, Do It Yourself RV, and Camper Report provide all the information you need to enjoy your RV. You’ll also find brand-specific information on additional forums like Air Forums, Forest River Forums, and Jayco Owners Forum.