Victron Three-Phase Home Battery Q&A and Cable Trunking

Steps

1. 1

   Step 1: Explaining the Main Switch and Fuse Rule

   One sharp viewer noticed in my previous video that I went straight from the main breaker to the subpanel. As Google points out, you are not allowed to go directly from your main switch to a subpanel without an automatic circuit breaker or fuse first. This is to ensure that the cable running to your shed or elsewhere is fully protected against short circuits or damage.

   I will follow this rule in my own setup by running from my main breaker through a 4-pole residual current circuit breaker to the shed. Inside the shed, I will have a main switch, followed by three 2-pole residual current circuit breakers, and then I will go to the inverters. I want to keep a clear view of the switches at all times so nobody turns them on while I am working on the system.

   Warning

   Never go directly from your main switch to a subpanel without a fuse or circuit breaker first to protect the cable.

2. 2

   Step 2: Why I Chose Victron Over Cheaper DIY Brands

   Viewer dromer1967 asked why I chose a cheap DIY battery but selected a relatively expensive system like Victron. The answer is that Victron is known for great quality and long lifespan. While cheaper brands exist, Victron is a reliable brand that I prefer to trust.

   Additionally, Victron is more like Lego. You can build it modularly, configure things, add separate modules, and expand your system to fit whatever you need. A viewer named Thiemo van Veenendaal mentioned that choosing a Deye hybrid inverter would have meant being done already, but with less content. I have never heard of that brand before, so I stick with Victron which has been producing since 1975 compared to Deye since 2007, giving Victron 32 more years of experience.

3. 3

   Step 3: Using an Old Laptop for HomeWizard Energy Monitoring

   Viewer edwinvivaro noted that I can install an old tablet with a QR code via Victron for an energy display, and mentioned he did the same in his living room under his TV. I did a similar setup under my TV by placing an old laptop that opens a webpage showing HomeWizard data.

   Via HomeWizard, I can see exactly what our current power consumption is, how the phase distribution looks, what we have generated, how much we consumed, and our daily balance. It is not that I stare at the screen all day, but it is very fun to casually check how we stand with the power balance. Later on, I plan to use this laptop or another screen for the Victron system as well.

   What I used

   Item	Amount	Notes
   Laptop	1	Old laptop used to display HomeWizard webpage
   Tablet	1	Alternative option mentioned by viewer

4. 4

   Step 4: 3D Printing Custom Cable Trunking Covers

   Viewer bartconinckx mentioned that people might nitpick about 3D printing parts of the cable run, though he did it himself using PETG. As you know, I do a lot with laser cutters and 3D printers, and I print everything from small brackets up to complete wind turbine blades.

   When I mounted my cable trunking against the brick wall, my holes had to go through the wall, causing a small piece of the wall to break off near the end of the trunking. To avoid leaving a small gap where the cables are visible, I used my 3D printer to design a nice cap that fits over the cable trunking to cover the cable neatly. While it does not change the electrical safety, it does look a lot better.

   What I used

   Item	Amount	Notes
   3D printer	1	Used to print custom cable trunking covers
   PETG filament	1 spool	Used for printing durable parts

5. 5

   Step 5: Discussing Battery Fire Safety and Extinguishers

   Tom Straetemans asked if I will make an automatic shutdown mechanism in case of fire. I am looking into how to best integrate this with Victron to shut down above a certain temperature, and I am also looking into adding a fire extinguisher in the steel cabinet. However, water extinguishers are useless for electrical fires, powder extinguishers leave a mess, so a CO2 extinguisher is best for extracting heat since it is ice cold and chokes the oxygen without damaging battery cells.

   There is a huge difference between battery chemistries. While lithium-ion cells in hoverboards, electric scooters, and Teslas can suffer thermal runaway and spray open oxygen to fuel fierce fires, LiFePO4 cells do not do this. The electrolyte inside LiFePO4 cells is not flammable, and if a cell faults, the vent on top opens to let pressure out without a violent explosive fire.

   • Water extinguisher

   • Powder extinguisher

   • CO2 extinguisher

   Tip

   CO2 extinguishers are great for electrical fires because they remove heat and choke oxygen without damaging battery cells.

   What I used

   Item	Amount	Notes
   CO2 fire extinguisher	1	Recommended for extracting heat without damaging battery cells

6. 6

   Step 6: Viewer Compliments and Future System Expansion

   AlexanderKoelewijn left a nice message saying it is nice to see people work neatly on DIY projects at home after seeing enough messy projects. I admit I make mistakes too, which serve as a learning curve, and I try to share what I learn with you.

   I have currently hung up one MultiPlus unit while the other two are still underway due to family circumstances. For the main cable running from the meter cabinet to the shed, I am using a 5-core 6 square millimeter cable over a length of 5 meters. According to internet specifications, a 6 square millimeter cable can safely handle 25 amperes up to 70 meters, so 5 meters will cause no problems at all.

   What I used

   Item	Amount	Notes
   5-core 6 mm² cable	5 m	Run between the meter cabinet and the shed

7. 7

   Step 7: Addressing Low-Frequency Transformer Noise

   Sikker de Baard mentioned that there is a thick transformer in the MultiPlus that vibrates at 50 Hz, and noted that using three hanging points and thick rubber vibration dampers stopped him from hearing it anymore. I hear this from many people, as the MultiPlus makes quite a sound when working hard, and unfortunately, there is not much we can do about the transformer itself.

   Many people also report that the cooling fan makes a lot of noise because it is driven by a very low PWM frequency, causing it to vibrate and make an annoying humming sound at lower speeds. Replacement controllers are available to fix this if you want it as quiet as possible, and I plan to install replacement controls since I want my setup to be as silent as possible.

8. 8

   Step 8: Takeaways

   • Always protect subpanel cables with a fuse or circuit breaker directly from the main switch.

   • Victron offers a modular and reliable system with extensive upgrade options.

   • 3D printing with PETG allows you to create custom covers for a neat finish.

   • LiFePO4 batteries are much safer and less prone to violent thermal runaway than lithium-ion cells.

   • CO2 fire extinguishers are ideal for electrical fires because they remove heat safely.