Phase switching on Zaptec GO 2 not working

[netsloh]

Describe the bug

I am currently struggling with the phase change from single-phase charging to three-phase charging on the Zaptec Go 2 wallbox. Fast charging with three phases works perfectly.

However, if the charging process starts in PV mode and evcc switches from single-phase charging to three-phase charging, it usually does not work.

I have attached two support files. In the file evcc-20251225-134840-trace.log, you can see that the switch to 3P took place at 13:47:06 and that the switch worked.

In the file evcc-20251225-140242-trace_NOT.log, you can see that the switch was also made at 13:57:20, but the change did not work.

I have already opened a ticket with Zaptec. A setting has been changed and, according to support, it is apparently no longer a problem with the box.

Update 2025/12/26:

A phase change should have taken place today at 12:18 p.m., which I triggered via power consumption. The GUI did not display the usual “switching up” symbol or a timer. I can't find any reference to this in the debug file either. I have added the debug file evcc-20251226-122406-debug.log. It's all very strange.

evcc-20251225-134840-trace.log
evcc-20251225-140242-trace_NOT.log

evcc-20251226-122406-debug.log

Steps to reproduce

1. Start charging with 1P
2. Wait for phase switching to 3P

Configuration details

# open evcc at http://evcc.local:7070
network:
  schema: http
  host: evcc.local # .local suffix announces the hostname on MDNS
  port: 7070

log: error

# unique installation id
plant: 123456

interval: 30s # control cycle interval

meters:
- name: HM2
  type: template
  template: sma-home-manager
  usage: grid
  host: 192.168.1.63

- name: Tripower 
  type: template
  template: sma-inverter
  usage: pv
  host: 192.168.1.240 # IP-Adresse oder Hostname
  password: "1234" # Passwort für Benutzergruppe Benutzer (optional) 

vehicles:
- type: template
  template: tesla
  title: Tesla Model 3
  clientId: 12345
  accessToken: 12345
  refreshToken: 12345
  vin: 12345
  capacity: 79
#  targetsoc: 90
  icon: car
  name: tesla

site:
  title: Zuhause
  meters:
    grid: HM2
    pv: Tripower

hems:
  shm: sma
  AllowControl: false

chargers:
  - name: go-e-charger
    type: template
    template: go-e-v3
    host: 192.168.1.54 # IP-Adresse oder Hostname
  - name: Zaptec-GO-2
    type: template
    template: zaptec
    id: # ID, Wallbox ID (optional)
    user: 12345 # Benutzerkonto, bspw. E-Mail Adresse, User Id, etc. (optional)
    password: 12345 # Passwort, Bei führenden Nullen bitte in einfache Hochkommata setzen (optional)
    passive: # Passivmodus, evcc erteilt nur Ladefreigaben/Ladesperren (keine Stromregelung). Aktiviere diese Option nur, wenn die Wallbox Teil eines externen Lastmanagement Systems ist und Stromänderungen ablehnt (HTTP 403). (optional)

loadpoints:  
- title: go-e-charger
  charger: go-e-charger
  mode: pv
  vehicle: tesla
  phases: 0
  mincurrent: 6
  maxcurrent: 16
#  resetOnDisconnect: true
  guardduration: 5m
  priority: 0
  enable:
    threshold: 0
    delay: 1m
  disable:
    threshold: 0
    delay: 3m
- title: Zaptec-GO-2
  charger: Zaptec-GO-2
  mode: pv
  phases: 0
  mincurrent: 6
  maxcurrent: 16
#  resetOnDisconnect: true
  guardduration: 5m
  priority: 0
  enable:
    threshold: 0
    delay: 1m
  disable:
    threshold: 0
    delay: 3m
tariffs:
  currency: EUR # (default EUR)
  grid:
    # static grid price
    type: fixed
    price: 0.29 # [currency]/kWh

  feedin:
    # rate for feeding excess (pv) energy to the grid
    type: fixed
    price: 0.08 # [currency]/kWh

sponsortoken: 12345

Log details

See files

What type of operating system or environment does evcc run on?

Linux

External automation

• I have made sure that no external automation like HomeAssistant or Node-RED is active or accessing any of the mentioned devices when this issue occurs.

Nightly build

• I have verified that the issue is reproducible with the latest nightly build

Version

0.211.1 (5253330)

[andig]

/cc @tbaehler

[netsloh]

Zaptec support changed a setting again, but I couldn't test it because of the weather. Even if it works, I still don't understand why EVCC sometimes doesn't even try to switch over. I haven't observed this behavior with my go-e charger in the last > 2 years.

PS: Perhaps a simulation mode would not be a bad idea. It would allow you to test different PV surplus values. However, I don't know how often this causes problems...

[andig]

Evcc always does the same. Maybe the Zaptec implementation doesn‘t. Only log analysis can tell.

[tbaehler]

you need to allow the phase switching in the zaptec portal.
Go to portal.zaptec.com open settings -> installations select your wallbox --> go to Settings
Then choose Tab Power Management.
Make sure that "Allow chargers to return to three phase charging is enabled"
Make sure that "Switches allowed before locking to single phase is set to your needs. Otherwise zaptec is locked to single phase

[andig]

@tbaehler would you mind adding this to the template? Seems it's not entirely obvious.

[netsloh]

I had those settings from the start:

They where discussed here:
#23278 (comment)

Zaptec Support changed another Setting after that (I' didn't see a difference in the zaptec portal). That didn't do the trick, now they seem to have switched to 6A.

But for me to test it, it has to stop snowing first. ;-)

[helijunky]

With Zaptec, the phase switch is not executed until the current is updated. That means the phase switch is blocked until the current is set to another value. That's why phase switching is sometimes delayed when there is no current adjustment. This behaviour has been confirmed by Zaptec support for Zaptec Pro, but it might also apply to GO.

I have implemented two things to fix this:

1. milliampere steps for current (api chargerex)
2. update current by +/- 0.1A immediately after phase switching to force the execution

It works very well in both directions 1p->3p and 3p->1p

You can try it using my branch: https://github.com/helijunky/evcc/tree/feature/api-chargerex

[andig]

@helijunky wanna open a PR?

[netsloh]

@helijunky Thank you very much. I'll definitely give it a try!

[helijunky]

@helijunky wanna open a PR?

#26573