Ac switch turns off when L1 returns in three phase system

We have a 3-phase system. Multiplus 2 10000. At the setup stage, we turned on the A C side. without a battery. To check, we turned off the Inverter L1 button, the AC output L2 and L3 also turned off automatically. The next step is to turn on L1 inverter and during the switching of the relay in the middle of the inverter, the input AC break for all 3 inverters (100 A) turns off the input AC voltage automatically.

9.1 Webinar with Margreet Leeftink - Three-phase and parallel system theory (43:36)

They do the same thing in this video, but they don’t show the switching moment. Why does it switch off? :grinning:

Why are you powering a system without a battery? This is unsupported, the system is not designed to be operated like that and you risk damaging the input relays.

1 Like

for setting up inverters. I have not seen information that they cannot be turned on without a battery. when setting up, you can use either the network or the battery. what happens to the input relay when switching on without a battery?

You just need to read the manual.
The startup/connection process is absolutely clear:
Connect battery THEN connect AC.

It has been stated many times in the forums as well, easily searched, that these systems should not be run without a battery. They are pre-charged via battery.
Powering without a battery will put stresses on the input relays and cause unexpected operation.

1 Like

thank you for your reply. I am from Ukraine and we in the country from the war need to quickly learn new information, and viktron has a lot of information that needs to be learned, it is good because there is the necessary information. Can you help us check our system or tell us what points we need to pay special attention to? Now we begin the installation of DC wiring.

after the first time, do not turn on the inverters until they are fully connected.

Couple of comments just based on your picture:

  1. Add batteries
  2. Wires to bus bar is way to small to handle 10000W for inverters, looks like you have 4AWG or so. You have 200A each inverter can use from battery, you need at least 2x1AWG for each positive and negative wire for each inverter, otherwise you will burn the wire or the house
  3. For 3 phase system installation is better to find proper installer as inverters need to be properly configured. Avangard is one of the trusted installer in Ukraine

β€”β€”β€”β€”
Edit after I posted this: I see inverters are 140A, so you need something like 0AWG or so, check in manual

β€”β€”β€”β€”
Edit after edit :slight_smile: disregard my last comments about wires size - I see you connected 2 wires per positive. Just be sure that total size is proper one

  1. batteries are ready - custom assembly 53 kWt.

  2. 50 mm2 cable, two pieces for positive and negative. the total cross-section will be 200 mm2 per inverter. by the way, with the choice of cable, we have the β€œKGNV” specification, but two different types. Added a photo.

question about the cable.
A) left cable - rigid internal insulation and soft external insulation are used. - all internal wires in one.
B) Right - the internal insulation is soft, the internal wires consist of 5 separate wires that are woven into one.

  1. thanks I will contact them to see if they can set up the system.

The manual has all the recommendations including wiring and fuse size
Your bus bar is a bit small. It should be equal at least to the sum of the (2x 50mmΒ² x 3) cable for the DC.
And the gauge wire from the battery bank to the bus the same. (Or more)
This would be true even if it was not victron.

  1. bus bar : pure copper 50 x 10 mm = 500 mm2
    length 600 mm

Are the DC cables the same length on all three Multis?

the first inverter is 75 cm, the second is 35 cm. It was planned to compensate for the length on the negative bus.

You MUST have the same length of ALL cables from inverters to DC bus and from DC to batteries. Please read this guide https://www.victronenergy.com/upload/documents/The_Wiring_Unlimited_book/43562-Wiring_Unlimited-pdf-en.pdf