Sanity Check on T6 Electrical System Design

[Scottishstu]

Hi everyone,


I’m in the middle of converting my 2018 VW T6 LWB and before I start ordering the remaining electrical components, I was hoping to get a sanity check from those with more experience.


The van currently has the factory leisure battery wiring under the passenger seat, so there’s an existing 10mm² feed from the engine bay. Rather than running a new cable, my plan is to use this and limit the Victron Orion XS to 30A.


Planned system

• Fogstar Drift Gen2 230Ah underseat lithium battery (driver’s seat)
• Victron Orion XS 12/12-50A DC-DC (limited to 30A)
• Victron Blue Smart IP22 30A mains charger
• Victron SmartShunt 500A
• Eberspächer Zeliox ZCM6
• 250A positive busbar
• 250A negative busbar
• 200A MEGA main fuse

12V Loads


The van will be running:

• Dometic NRX50 compressor fridge
• Autoterm diesel heater
• 6 LED ceiling spotlights
• 2 rear reading lights
• LED ambient lighting
• USB-A / USB-C charging sockets

I’m not fitting an inverter at this stage as I generally camp on hook-up or use portable power if needed, but I would like to leave provision for future solar.


ZCM6


Rather than using a traditional blade fuse board, I’m planning to use an Eberspächer Zeliox Control Module (ZCM6), which I was fortunate enough to be gifted.


From what I understand, it acts as a programmable 12V power distribution module with six individually protected outputs, replacing the need for a conventional fuse box. My plan is to use it to control and distribute power to the lights, USB sockets, fridge, water pump, etc.


If anyone has experience using a ZCM6 in a camper conversion, I’d be interested to hear your thoughts.


Proposed cable sizes

• Battery → MEGA fuse → positive busbar: 35mm²
• Battery negative → SmartShunt → negative busbar: 35mm²
• Factory feed → Orion input: existing 10mm²
• Orion output → positive busbar: 10mm²
• Blue Smart → busbars: 10mm²
• ZCM6 → busbars: 16mm²

Proposed fuses

• Main battery: 200A MEGA
• Orion input: 40A MIDI
• Orion output: 40A MIDI
• Blue Smart: 40A MIDI
• ZCM6: 80A MIDI

230V System


The EHU inlet is mounted under the bonnet and feeds a consumer unit under the passenger seat. From there it supplies:

• Victron Blue Smart charger
• One 230V radial socket circuit

Questions

1. Does the overall system architecture look sensible?
2. Does the fuse strategy look sensible?
3. Is 35mm² the right choice for the battery backbone?
4. Are the 40A MIDI fuses appropriate for the Orion when limited to 30A?
5. Would you use 10mm² or 16mm² from the Orion output to the busbar, considering it’s only around 0.5m?
6. Is there anything obvious you’d do differently before I start ordering everything?

Thanks in advance. I’ve spent quite a bit of time researching this and want to make sure I’ve got the fundamentals right before I start buying everything. I’m happy to change the design if there’s a better or safer way of doing it.

 

[t0mb0]

A wiring diagram might help, but my initial questions would be:

1) Not seen a ZCM6 before but is it really designed to replace a fusebox? Fuses are very simple devices for a reason - there's not much to go wrong. If this is thing isn't giving you genuine functionality you actually need, I'd probably eBay it...

2) Not sure I understand how a positive busbar fits in? These aren't usually used because anywhere you would use one you would usually use a fusebox? The only scenario I can think of is where you're joining a bunch of wires of the same size/rating such that the incoming fuse protects all of them - this isn't very usual though, usually you're splitting off into smaller feeds, in which case you need protection (i.e. a fusebox) anyway?

3) I would probably cable/fuse the Orion up to its full rated output, feels a bit weird to rely on a software setting to prevent something blowing.