Best 2000W Inverters for Grand Design RV: Complete Installation Guide

Short Answer

For your Grand Design TT with factory 10/2 Romex wiring, I recommend the Victron Energy MultiPlus 12/2000/80-50 or AIMS Power 2000W Pure Sine Wave inverter. Given your prewired loop limitation, go with an external automatic transfer switch (ATS) like the Progressive Dynamics PD9245CV or Parallax Power Supply 7345 rather than relying on an internal switch, as this will give you better reliability and easier troubleshooting access in your travel trailer setup.

Understanding the Problem

Your Grand Design came factory-prewired with 10/2 Romex, which is actually perfect for a 2000-watt inverter installation. The 10 AWG wire is for the AC side output of the inverter and can safely handle the 20-amp AC load. However, you'll need much larger DC wiring (see DC wiring section below) to handle the approximately 185-195 amps that a 2000-watt inverter will draw from your 12V battery bank under full load.

The key consideration with your setup is that you have three main options for switching between shore power and inverter power: an inverter with built-in transfer switching, a separate external ATS, or a manual external switch. Each has pros and cons, but with a travel trailer, external components are generally preferred because they're more accessible for maintenance and troubleshooting than components buried inside an inverter housing.

Your existing Romex wiring suggests Grand Design installed a basic inverter prep package, which typically includes the AC wiring from the main panel to a designated inverter location, but you'll need to verify what circuits are actually on the inverter loop. Common circuits include outlets, lights, and sometimes the microwave, but usually not high-draw items like the air conditioner or water heater.

What You'll Need

For the inverter itself, you'll need either the Victron Energy MultiPlus 12/2000/80-50 (around $650-750) which includes a built-in 80-amp battery charger and transfer switch, or the AIMS Power PWRINV200012W (around $300-400) which is a pure sine wave inverter without built-in transfer switching. The Victron is the premium choice with excellent build quality and smartphone monitoring capabilities.

If you go with a basic inverter like the AIMS, you'll need a separate automatic transfer switch. The Progressive Dynamics PD9245CV (around $150-200) is specifically designed for RV applications and can handle 30-amp service. Alternatively, the Parallax Power Supply 7345 (around $120-180) is another solid RV-specific ATS option.

You'll also need appropriate DC wiring from your battery bank to the inverter location. Plan on 4/0 AWG cable or larger (see manufacturer specifications) for the 6-8 foot run typical in most travel trailers to handle the high amperage, along with a 250-amp fuse or breaker within 18 inches of the battery bank. Budget around $100-150 for proper DC cabling and fusing.

Additional items include battery bank expansion if needed (most 2000W setups work best with at least 400Ah of lithium or 800Ah of lead-acid), mounting hardware for the inverter, and potentially a battery monitor like the Victron BMV-712 to keep track of your power consumption.

How to Fix It

SAFETY FIRST: Turn off the main breaker and test all circuits with a voltage tester before beginning any electrical work. Start by locating your inverter prep wiring in the Grand Design. This is typically in a basement compartment or under a dinette bench. You'll find the 10/2 Romex terminated in a junction box, along with a 12V DC wire run back to the battery compartment. Verify which circuits are on the inverter loop by checking your electrical panel - they should be clearly marked or you can trace them with a circuit tester.

Mount your chosen inverter in a well-ventilated area near the existing prep wiring. The Victron MultiPlus needs at least 6 inches of clearance on all sides for cooling. Secure it firmly using the mounting brackets, as road vibration can cause connections to loosen over time. Connect the existing 10/2 Romex to the inverter's AC output terminals using the appropriate terminal connections as specified in the inverter manual.

Run your DC power cables from the battery bank to the inverter location. Install a 250-amp fuse or breaker at the battery end within 18 inches of the positive terminal. Use proper marine-grade terminals and ensure all connections are tight and protected from corrosion. The negative cable should connect to your RV's main DC negative bus or directly to the battery negative terminal.

If using a separate ATS, install it between your shore power inlet and main breaker panel. This typically requires some rewiring of your main electrical panel, so ensure you're comfortable with this level of electrical work or hire a qualified RV technician. The ATS will automatically switch between shore power and inverter power based on availability and quality of shore power.

Leave It to the Experts

While many RV owners can handle the inverter installation itself, the integration with your main electrical panel and ATS wiring should be done by a certified RV technician if you're not comfortable with 120V electrical work. Improper installation can create fire hazards or damage to your RV's electrical system. Most RV service centers charge $300-500 for professional installation of a customer-supplied inverter system.

Consider having the work done professionally if you're planning to add significant battery capacity, as this often involves modifications to your charging system and may require updated converters or DC-to-DC chargers. A qualified technician can also perform load calculations to ensure your planned usage won't exceed the capabilities of your electrical system or cause interference with other RV systems.

Professional installation also ensures proper grounding and bonding, which is critical for both safety and optimal inverter performance. Many warranty claims are denied due to improper installation, so the professional route often pays for itself in peace of mind and warranty protection.