445/455/458 - Victron Autotransformer

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Victron Autotransformer

Printed From: myHanse.com
Category: Hints & Tips
Forum Name: 445/455/458
Forum Description: 445/455/458 Hints, Tips and News
URL: https://www.myhanse.com/forum_posts.asp?TID=15465
Printed Date: 27 March 2026 at 03:08
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com

Topic: Victron Autotransformer

Posted By: MrPotatoHead
Subject: Victron Autotransformer
Date Posted: 08 December 2025 at 22:27

Hi, can someone with the 120V American option please post a picture of the internal wiring of the Victron Autotransformer? What is published in the documentation does not make sense based on what I am measuring. Thanks!

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Hanse 458 #126

Replies:

Posted By: Arcadia
Date Posted: 09 December 2025 at 13:00

I don’t have a photo but you should be getting 230-240 on the input side where the breakers are. This voltage comes from the inverter, generator or shore. The output is 115-120 volts and is between L1 and N on connection PCB. L2 is not used. My diagram supplied by Hanse shows hot and neutral reversed on the output, but actual wiring is correct. To be sure you should measure voltage between neutral and ground at the service outlets. It should measure zero volts.

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Leon / ARCADIA
2018 Hanse 588
Sag Harbor, NY

Posted By: MrPotatoHead
Date Posted: 09 December 2025 at 18:20

Thank you, yes, that is what the schematic shows. But, I am measuring the following:

L1 - L2 = 240V

L1 - N = 120V

L2 - N = 120V

L1 - GND = 240V

N - GND = 120V

L2 - GND = 0V

Based on that, I believe, N (Blue) should be connected to L2 and L (Brown) should be connected to N. GND shows that it is connected to CASE which is also connected to PE.

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Hanse 458 #126

Posted By: MrPotatoHead
Date Posted: 09 December 2025 at 19:02

OK, I think I figured it out. Load (hot) and Neutral are mislabeled on the input side as well. Getting that correct yields the correct and expected result on the output side.

FYI, the problem that I was seeing was with the inverter I installed. It has an automatic detection and pass-through feature. So, to install it I simply inserted it between the 120V output of the autotransformer and the 120V input to the AC panel. The autotransformer had labels written on the breaker (looked like pencil) and I reconnected it per the labels. This was obviously wrong... It seemed to work but the pass-through relay would just randomly trip (likely a gnd fault) regardless of load.

Lesson learned is to TAKE PICTURES and ignore the labels.

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Hanse 458 #126

Posted By: Arcadia
Date Posted: 09 December 2025 at 19:33

FWIW, the typical Hanse set up uses a 240 volt inverter/charger and it is placed after the shore power and generator (both 240 v) and then supplies the auto transformer via the feed thru. You placed your inverter AFTER the auto transformer. Is it a 120 volt unit?

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Leon / ARCADIA
2018 Hanse 588
Sag Harbor, NY

Posted By: MrPotatoHead
Date Posted: 09 December 2025 at 22:03

Yes, I installed a 120V inverter. Promariner TruPower 2000ps

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Hanse 458 #126