220V 60h USA >> Quattro 15k 230V>> Dual Victron autotransformer >> 160A @ 240V and 50A @ 120V

DIY
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Apologies for the length, but I wanted to ensure I provide adequate context. I am working on a food truck that will operate all its equipment from a battery-based system. Below, I have outlined the system specifications, the proposed setup, and a few technical questions

System Overview:

We are aiming to run the entire food truck operation electrically, with a 48V / 80kWh battery system, which must be fully charged daily. A 3kW solar array is available, but it alone cannot meet the daily charging requirements, hence the need to integrate a Level 2 EV charger for supplemental charging.

System Components and Configuration:

  1. Battery Configuration:
  • Five (5) 48V x 16kWh batteries
  • Each battery lands on a Victron Lynx Distributor, aggregating to power a 15kVA Victron Quattro inverter/charger
  • The Quattro’s maximum DC input current is 350A @ 48VDC
  1. Charging Source:
  • A ChargePoint Level 2 EV charger providing 50A @ 220V
  • Capable of charging the battery system from 10% to 90% in approximately 7 hours
  1. Grounding:
  • The neutral-to-ground bond will be disabled on the Quattro to allow for external bonding control
  1. Load Requirements:
  • Max 160A @ 240V
  • Max 50A @ 120V

Proposed Setup:

Input Side:

  • The Level 2 charger will supply 50A @ 220V via two hot wires and one ground wire to a J1772 Type 1 Socket Inlet (preferred).
  • An optional secondary shore power inlet (also 50A @ 220V) may be installed.
  • Both inlets will exclude a neutral conductor for safety considerations.
  • An Automatic Transfer Switch (ATS) will manage the switch between shore power and EV charger input.

Output Side:

  • Each of the Quattro’s AC outputs will connect to a 100A Victron Autotransformer.
    • Configuration: 2 x 100A @ 220V and 2 x 32A @ 120V
  • both autotransformers outputs will feed into the main AC breaker panel.

Technical Questions:

  1. Input Side Safety:
  • Is this input configuration (two hot wires and ground only, without neutral) safe and compliant, particularly with the use of a J1772 inlet and ATS?
  1. Equipment Grounding:
  • Given the high voltage and current in the system, is it safe and advisable to bond equipment enclosures (such as inverter housings, breaker panels, transformer casings) to the vehicle chassis?
  1. Neutral Bonding Strategy:
  • Since the grid input does not supply a neutral, and the only neutral exists on the output side of the autotransformers, do I still need to establish a neutral-to-ground bond in the AC breaker panel?
  • If so, what are the implications of bonding in the panel while the system is charging or in passthrough mode? Is there a risk of back-feeding or ground loop issues?
  1. Autotransformer Isolation:
  • What is the recommended method to **wire the two autotransformers outputs ** to the AC breaker panel in such a way that, if one transformer shuts down or fails, power from the other transformer does not back-feed into the inactive unit?

Thank you very much for your time and assistance.

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Anything metal that contains hazardous AC voltages should be bonded to AC ground.
The real question is, “should AC ground be bonded to the vehicle chassis?”
I would think so, but I’m not an expert on vehicle grounding.

There must always be one and only one neutral-ground bond at all times regardless of power configuration. That can be very challenging to implement with an AT.

The big problem with using an autotransformer is that its neutral must be bonded as well.
But if you mix neutrals, the AT will try to balance shore power (not good).
Or, if there are two N-G bonds while in passthrough, the ground lines will carry objectionable current (very bad). There is no clean way to fix this without switching neutrals, and that is dangerous as well. Autotransformers are fine in fixed static installations, and painful for mobile use where multiple power sources are available.