RV Leveling & Inverter Fuse Sizing: What You Need to Know

When it comes to setting up your RV or upgrading your electrical system, a few seemingly simple questions can have major consequences if done incorrectly. Whether you're trying to figure out when to extend your slides or what size fuse to use with your inverter, we've got the answers. Let’s dive into these two frequently asked questions that every RVer should understand.

When Should You Level Your RV and Operate Slides?

One of the most common questions new RVers have is: Should I level my RV before or after I extend the slides?

The answer depends on what type of RV you have:

For Towables (Travel Trailers & Fifth Wheels):Always level first, then extend the slides. Towables typically have slides that are essentially large boxes sliding into square openings. If the RV isn’t level, these slides can rack—meaning they move unevenly, which could lead to binding, mechanical damage, or motor failure. Once you're ready to leave, bring the slides in before reconnecting to your tow vehicle. Keeping the unit level throughout this process helps preserve the alignment and integrity of your slide mechanisms.

For Motorhomes:This can vary. You should always check your owner’s manual. Some manufacturers recommend extending the slides before leveling, while others recommend the opposite. Follow the factory instructions to prevent unnecessary wear and tear.

In short:

• Towables: Level first, then slides out. When leaving, slides in before reconnecting to your truck.

• Motorhomes: Follow your manufacturer’s guidelines.

What Size Fuse Should You Use Between Your Battery and Inverter?

If you're installing an inverter, knowing the proper fuse size is critical for safety and performance.

Here’s how to determine it:

1. Determine your inverter's wattage. For example, a 2000W inverter running on a 12V system will pull around 166 amps (2000W ÷ 12V = ~166A).

2. Choose a cable that can handle more than the continuous current your inverter will draw. In this case, a cable rated for 200–250 amps is ideal.

3. Fuse to protect the cable, not the inverter. Never install a fuse that exceeds the cable's amp rating. For a cable rated for 250 amps, use a 200A–250A fuse.

Always size the fuse conservatively to handle the heat and prolonged run times common in RV systems. It’s better to oversize your cable and fuse than to risk overheating or electrical failure.

Final Thought

Whether you’re troubleshooting power upgrades or just want to avoid costly slide-out repairs, understanding these foundational RV setup principles can save you time and money.

Looking to upgrade your RV’s power system?

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