Victron VE.Bus Virtual Switch Generator Setup Guide

Updated 6 September 2026 · By SolarNevs Research Desk, Dealer surveys + verified sources · 1 source · Method ↗

Key Takeaways

  • The VE.Bus Virtual Switch automates generator start/stop based on system conditions.
  • Configuration requires VEConfigure software, not direct inverter controls.
  • Relay contact order for wiring varies significantly by MultiPlus/Quattro model.
  • Always isolate all power sources (PV, battery, AC) before wiring the alarm relay.

How do I set up my Victron system to automatically start and stop a generator?

The Victron VE.Bus Virtual Switch feature allows your MultiPlus or Quattro inverter/charger to automatically manage a generator. This automation helps maintain battery state of charge or provide backup power when grid conditions are poor. You configure this feature using the VEConfigure software.

Diagnosis: Checking your Victron model and relay connections

Before configuring the Virtual Switch, it is important to identify your specific Victron model and understand its relay connections. The physical wiring of the generator control input to your Victron inverter/charger depends on the model.

  1. Identify your MultiPlus or Quattro model. The relay contact order varies significantly between models.
  2. Locate the "Alarm relay" connector. This is the relay and connector block designed for generator control.
  3. Determine the correct relay contact order for your specific model. This is critical for proper wiring.
    • MultiPlus and Quattro models of 3000VA and above: The contact order from left to right is Normally Closed (NC), Normally Open (NO), Common (COM).
    • MultiPlus-II models: The contact order from left to right is Normally Open (NO), Normally Closed (NC), Common (COM).
    • MultiPlus 500VA to 1600VA models: The contact order from left to right is Common (COM), Normally Closed (NC), Normally Open (NO).
    • MultiPlus Compact models: The contact order is Normally Open (NO), Common (COM), Normally Closed (NC).
  1. Note relay detachability. For MultiPlus and Quattro models of 3000VA and above, the relay block is detachable. For MultiPlus Compact models, this relay block is also removable. This can make wiring easier.
  2. For Quattro models used in a backup system, confirm AC-in wiring. The generator should be wired to AC-in 1, and the mains power should be wired to AC-in 2.

Configuration Steps

The VE.Bus Virtual Switch is configured using the VEConfigure software. This table outlines the key settings. Note that specific threshold values (e.g., battery voltage, state of charge) are not provided in the manual and must be set based on your specific battery type and system requirements.

Setting Name

Values/Description

Configuration Tool

Virtual Switch Feature

Select 'dedicated generator control'

VEConfigure

Stop generator when AC2 available

Check this box if you want the generator to stop when AC input 2 (e.g., grid) becomes available.

VEConfigure

Safety: Wiring the Alarm Relay

Working with electrical systems, especially those involving generators and inverter/chargers, carries inherent risks. Always prioritize safety.

  • Isolate Power: Before attempting any wiring to the alarm relay, ensure all power sources are completely isolated. This includes disconnecting the PV array, turning off battery breakers, and switching off all AC input and output breakers.
  • Insulated Tools: Use only insulated tools when working with electrical connections.
  • Avoid Short Circuits: Be extremely careful to prevent accidental short circuits across relay terminals or other components. A spanner across a battery bank can short hundreds of amps, causing severe burns or equipment damage.
  • Ventilation: If your generator is combustion-based, ensure adequate ventilation to prevent carbon monoxide buildup.
  • Authorized Service: Opening the inverter/charger unit for any reason other than accessing the detachable relay block (if applicable) is authorized-service work and should only be performed by qualified personnel.

When to call a technician instead

While configuring the Virtual Switch is a software task, the physical wiring of the alarm relay requires careful attention. If you are unsure about identifying your model's relay contact order, performing the wiring safely, or setting appropriate generator start/stop thresholds, it is best to consult a qualified Victron installer or electrician. Incorrect wiring can damage your equipment or the generator, and improper settings can lead to inefficient system operation or premature battery wear.
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Frequently asked questions

What is the Victron VE.Bus Virtual Switch for generator control?

The VE.Bus Virtual Switch is a feature in Victron MultiPlus and Quattro inverter/chargers that allows for automatic control of a generator. It uses programmable conditions to start and stop a generator, integrating it seamlessly into your energy system.

Which Victron models support generator control via Virtual Switch?

The VE.Bus Virtual Switch for generator control is available on MultiPlus and Quattro models. Specific relay contact orders vary by model, including MultiPlus and Quattro models of 3000VA and above, MultiPlus-II models, MultiPlus 500VA to 1600VA models, and MultiPlus Compact models.

How do I configure the Virtual Switch for generator control?

Configuration is done using the VEConfigure software. You navigate to the Virtual Switch settings and select 'dedicated generator control.' You can also set options like 'Stop generator when AC2 available'.

What are the relay contact orders for different Victron models?

The relay contact order varies by model. For MultiPlus and Quattro models of 3000VA and above, it's Normally Closed (NC), Normally Open (NO), Common (COM). For MultiPlus-II models, it's NO, NC, COM. MultiPlus 500VA to 1600VA models use COM, NC, NO, and MultiPlus Compact models use NO, COM, NC.

Where do I connect the generator to a Victron Quattro for backup?

For Quattro models used in a backup system, the generator should be wired to AC-in 1, and the mains power should be wired to AC-in 2. This ensures correct operation with the Virtual Switch generator control.

References

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