Victron Energy 50A Split-phase Shore Power Solutions

Modern RV comforts like air conditioning and clothes dryers can be difficult to run because many RV power systems can’t keep up with the high power demands. Many sites aren’t equipped to supply the split-phase power that these appliances require, or any power at all. 

Victron Energy’s lineup of inverter/chargers allow you to have your cake and eat it! - now you can boondock or choose lower power shore power hookups without having to roast in the summer heat or not have access to a clothes dryer when it’s cold and wet outside. Having the right power system can make all the difference in your comfort level on outings.

In this article, we'll explore how a 50A split-phase shore power setup and Victron's inverter/chargers can enable you to run split-phase 240V power seamlessly in your RV.

Case Study: Victron System Upgrade in a Brinkley Model Z

Kathy and Gary's power system system includes:

• 2 x 3,000VA MultiPlus-II inverter charger converts DC power from the battery bank to AC power to run appliances. It also charges batteries with shore power when available. When connected to 50A service the batteries are able to be refilled with 2800W+ of charging.
• 6 x 12V 200Ah LiFePO4 batteries provide enough power to run the RV for 48 hours.
• 720 W of solar mounted on the roof of the fifth wheeler.
• 2 x 50 Amp SmartSolar MPPT solar charge controllers convert energy from the solar panels and store it in the battery bank.
• An Orion-Tr Smart DC-DC charger connected to the battery and alternator in the tow vehicle maintains and recharges the batteries while driving.
• A Lynx Distributor consolidates DC charging sources and loads. 
• A Cerbo GX device is the central communications hub between the battery bank, inverter, and other Victron ​Energy devices. The Cerbo also uploads data to the Victron VRM portal for online system monitoring and provides visual and audible alarms if any system parameter needs attention. 
• A GX Touch 50 display panel mounted in the RV's control cabinet provides a data display and touchscreen controls for adjusting system parameters. 
• Ruuvi Bluetooth sensors monitor temperature and humidity in the equipment bay, RV refrigerator, and primary living space.

This system is able to make full use of a 50A shore power supply. While connected to shore power, the entirety of the loads on this system are able to be powered via pass-through, all the while charging the battery bank with nearly 3000W of power. This kit is a great option for anyone wanting to run high powered loads while on shore power, while still being fully capable of living off-grid for days at a time.

What is 50A Shore Power?

30A and 50A are the two main shore power options you’ll encounter in North America. 

30A typically refers to a single-phase 120-volt connection that can supply 30 amps. This is a great option for lower power devices, and in many places it’s all that is available.

50A shore power provides a split-phase 240-volt connection that is rated for 50 amps. “Split-phase” means that there are two 120V circuits that are 180 degrees out of phase. You can run standard 120V circuits from either hot wire (L1 or L2) to neutral, or you can connect higher power 240V devices across L1 and L2 to get 240V. This configuration is great if you want to run 240V appliances like a washer/dryer combo or a dual AC setup.

For purposes of this article, we will refer to 120V single-phase power and 240V split-phase power as 30A shore power and 50A shore power.

How Victron Inverter/Chargers Work with Split-Phase Power

There are two main options for designing a 50A shore power system with Victron inverter/chargers:

1. Only need high-power split-phase appliances on 50A shore power? Victron 2x120 Inverter/Chargers (Multiplus-II 2x120V and Quattro-II 2x120V) are a powerful option for systems that don’t have the battery capacity to run high-power loads when not connected to shore power. They can provide split-phase power when attached to split-phase 50A shore power. When split-phase 50A shore power isn’t available, high-power loads (see middle diagram below, AC out 2, L1-L2) are automatically shut off to preserve battery charge. When no shore power is available, AC Out 2 is completely disabled to disconnect non-critical loads. They also have a contactor that automatically bridges L1 and L2 when split-phase power is unavailable, so 120V loads will continue to operate.

Note: If the power to L1 and L2 is in phase, as in we are either a) feeding the system with 120V or b) inverting, the voltage between L1 and L2 will be zero. In that case, the 240V equipment can not power up, and you don’t have to worry about them turning on or experiencing low voltage.

2. Need high-power split-phase appliances when limited or no shore power is available? Thanks to the advanced features of the Multiplus-II line of inverter/chargers, two (or more!) 120V Multiplus-II units can be combined to provide split-phase power that rivals the power output of shore power. By using two Multiplus-II inverter/chargers, you’ll be able to run split-phase loads on demand. When you’re on shore power, you can use any excess power (up to a configurable limit) to charge your battery pack. One advantage of this system is that it can still be plugged into lower power 30A single-phase services to charge your batteries - and you’ll still be able to use split-phase appliances.

Conclusion

Victron's 2x120 inverter/chargers come in 12 and 24V 3000W models. With their unique switch gear and intelligence, they check all the boxes most RV owners have in an elegant package that meets the high standard set by Victron power systems.

If you’re unsure about how to set up these systems or need help sizing a Victron inverter/charger for your RV or upgrade, Intelligent Controls is ready to help. Send us a message and one of our experts will help you design a Victron power system to fit your needs.

Contributors: Dave Cutting, Technical Writer