victron energy 32 A Autotransformer Owner’s Manual

victron energy 32 A Autotransformer

Victron Energy Autotransformer

Specifications

• Pass Through Current : 32A and 100A

Product Description

• The Victron Energy Autotransformer (AT) is a versatile device that supports various wiring configurations. It is designed to enhance your system’s adaptability to different design and voltage requirements. Additionally, it can be used to balance loads in split-phase 120/240Vac systems. This autotransformer is particularly useful for specialty systems such as boats and vehicles, which may encounter different shore configurations while traveling. By offering flexibility and enabling connections to most grid configurations, the autotransformer simplifies electrical setups.
• The Victron Energy Autotransformer can create a Neutral to Ground bond within itself when used in conjunction with a Victron Energy MultiPlus or Quattro and interconnected relay terminals. This manual provides detailed instructions on how to safely install and wire the autotransformer, as well as explains its numerous applications. Section 2.4 delves into specific uses that can be realized by integrating an autotransformer into an installation. It is important to note that the AT does not provide isolation, and further specifications can be found in section 4.

Models
The autotransformer is available in two models

• 32A : Pass through current of 32A
• 100A : Pass through current of 100A

Both models have identical transformers. For more information, please refer to section 2.8.

Types of Use

Balancing a Generator or Stacked Inverters

• In some cases, the full power output from a split-phase supply source, such as a generator or stacked inverters, may be limited. This limitation arises because a single-phase load cannot draw more energy than its individual leg allows, even if the other leg is not fully utilized.
• To overcome this limitation and balance a generator or stacked inverters, the autotransformer can be utilized. By leaving the neutral of the split-phase supply unused, a new neutral can be created. Any load unbalance is absorbed by the autotransformer.
• The two legs of a split phase from an AT are independent from each other, with a fixed 180-degree phase shift between them. This phase shift results in a full opposite sine-wave of both legs, creating a double voltage from leg to leg rather than from leg to neutral.

FAQ

Q: Does the autotransformer provide isolation?
A: No, the autotransformer does not provide isolation. For more information, please refer to section 4 in the manual.

Safety

• These instructions are for use by qualified personnel only. Do not perform any servicing or installation other than that specified in the operating instructions unless you are qualified to do so. Incorrect installation or servicing may result in a risk of electric shock, fire, or other safety hazards.
• All electrical work should be performed in accordance with local and national electrical codes.
• This product is designed for indoor/compartment installation.
• Use insulated tools to reduce the chance of electrical shock or accidental short circuits.
• Select the wire size based on the protection provided by the circuit breakers.
• Before making any connections verify that the circuit breakers are in the off position including the inverter breaker. Double check all wiring before applying power.

The following safety symbols have been placed throughout this manual to indicate dangerous and important safety instructions.

CAUTION: This symbol indicates that failure to take a specified action could result in damage to the equipment.
Info: This symbol indicates information that emphasizes or supplements important points of the main text.

Introduction

Description

• The Victron Energy Autotransformer (AT) supports many different wiring configurations. It can increase your system’s ability
  to adapt to different design and Voltage requirements, and also be used to balance loads in split-phase 120/240Vac systems. Specialty systems such as boats and vehicles may face different shore configurations while traveling, an autotransformer can help by being flexible and enabling connections to most grid configurations.

• The Victron Energy Autotransformer has the ability to use a ground/earth relay to create a Neutral to Ground bond in the AT itself, if coupled with a Victron Energy MultiPlus or Quattro and the relay terminals are interconnected.

• This manual will explain the many uses for this device and how to safely install and wire it. Below there are general examples of four ways the Autotransformer can be applied. There are several specific uses that can be realized in the integration of an autotransformer into an installation and are explained in section 2.4. The AT does not provide isolation. See section 4 for specifications.

Models

• 120/240V – 32A
• 120/240V – 100A

Pass through current is 32A and 100A respectively, the transformers are 100% equal in both models. See more information in section 2.8.

Types of Use

Balancing

• Balancing a Generator or Stacked Inverters
• Full power from a split phase supply source such as a generator or stacked inverters is sometimes limited, as a single phase load cannot draw more energy than its individual leg will allow even though the other leg isn’t fully utilized.
• If balancing a generator or stacked inverters is required, the AT can accomplish this by leaving the neutral of the split phase supply unused, to create a new neutral, as shown in the illustration below. Any load unbalance is “absorbed” by the autotransformer.
• The two legs of a split phase from an AT are independent from each other, beside the fact there is a fixed phase shift between them. This (180Deg) phase shift means the sine-wave of both legs is in full opposite (creating a double voltage from leg to leg rather than that of leg to Neutral).

With an AT, energy from one leg can be “transferred“ to the other leg which creates a far higher total load level, unlocking the full potential of power available from a generator or stacked inverters..

See diagram below for wiring instructions.

Inverter Balancing

Stepping Up Voltage

• Alternative to Stacked Inverters.
• Loads such as deep well water pumps and air conditioning units sometimes require Split-Phase 120/240Vac power.
• When the available AC power source is not what is needed in the installation, the autotransformer can create the needed voltage by doubling the incoming voltage.
• The alternative to stacking two 120Vac inverters to provide a 120/240Vac Split-Phase is a single 120Vac inverter with an additional autotransformer.

Other possible cases for stepping up the Voltage are shown in the wiring diagrams below.

Step Up Mobile

Step Up Stationary

Step Up

Stepping Down Voltage

• Flexibility in Using Split-Phase for Single-Phase Inverters
• One case for using the autotransformer to step down voltage could be in installations that use a Split-Phase generator and a Single-Phase inverter, the autotransformer makes it possible to use all available power from both legs of the generator to power loads and to charge batteries.
• When the available AC power source is not what is needed in the installation the autotransformer can create the needed voltage by decreasing the incoming voltage.
• Other possible cases for stepping down the Voltage are shown in the wiring diagrams below.

Step Down

Step Down

Step Down

Ground Relay

• In most energy systems for residential or mobile use a TT configuration is used, which means the Neutral of the AC system is grounded. This is to ensure the GFCI breaker will trip in case there is an earth failure (The connection N/PE will ensure a current will flow in the secondary circuitry which is detected by the GFCI).
• As an autotransformer is also able in some systems to “create” a neutral different from the incoming neutral, a ground relay is included in the unit. This relay can be controlled by a Multi/Quattro (by disabling the internal ground relay in the inverter/charger through VE Config or Victron Connect and interconnecting the “ground relay” terminal block in Multi/Quattro and Earth terminal block in Autotransformer by Positive and Negative conductors. In some of the diagram examples in Section 2.4.1 through 2.4.3 it is mentioned when it is possible to use the ground relay.

When the Internal ground relay is not selected in VE Config or Victron Connect, there is 12V on the external terminal of the Multi/Quattro for the ground relay control (on all models 12/24/48V this voltage is 12V).

Temperature Protected

• In case of overheating, the autotransformer is disconnected from the supply. When the transformer is warm the fan will operate and the Red LED be illuminated. Disconnect some of the 120V load if this occurs.
• When the transformer is overheated the MCB will switch off. The little blue switch will be out of the MCB.
• To reset this manually cycle the circuit breaker.

Over Current Protection
In case of over current the MCB will switch off. Disconnect some of the load.

The MCB is for Over Current and Temperature Protection and switching the unit ON/OFF.

Sizing Limitations
The Autotransformer comes in two models, a 32A model and a 100A model. This value is defined in the amount of current there can be in pass through, so in other words the current which is forwarded without being converted. The transformer itself is equal in both models and has a 32A capacity (peak) and 28A nominal. This is the maximal current that can be used to transfer energy from leg to leg or from 120Vac to 240Vac.

Installation

Installation Considerations
Ensure that the Autotransformer is used under the correct operating conditions. Never operate it in a wet or dusty environment. The AT is rated to IP21.
Ensure that there is always sufficient free space around the product for ventilation (10cm or 4 inches), and that ventilation openings are not blocked. See specification table for dimensions in Section 4.
Install the product in a heatproof environment. Ensure therefore that there are no chemicals, plastic parts, curtains or other textiles, etc. in the immediate vicinity of the equipment.

Mounting

• Using a level if needed, install the wall hanger in the desired position with provided fasteners. Place AT on to wall hanger and pull down to achieve a snug fit. Install fasteners in the 2 holes provided at the lower portion of the enclosure.
• The AT can be mounted in any orientation. Note that the Vertical position is the optimal orientation because it has maximum heat dissipation and easy access the terminal board.

Wiring

• The Autotransformer has several possible configuration options and must therefore be installed correctly for the desired outcome. The terminal block may be used as an input for certain applications, and in other applications the terminal block is used as output.
• Remove cover by removing 4 fasteners found in all four corners. Carefully remove front cover keeping in mind the 3 LED status lights.
• See diagrams in Sections 2.3.1 through 2.3.4 for the placement of conductors that correspond with the desired configuration.

Conduit
Both models of the AT can be fitted with conduit if required. For the 32A model remove supplied cable glands/strain relief and replace with 1/2” (.5 inch) or ¾” (.75 inch) NPT (National Pipe Thread) conduit fittings. See illustration below. The 100A model will require lager conduit fittings.

Specifications

Enclosure Dimensions

Warranty

• This product has a 5-year limited warranty. This limited warranty covers defects in materials and workmanship in this product and lasts for five years from the date of original purchase of this product. To claim warranty the customer must return the product together with the receipt of purchase to the point of purchase. This limited warranty does not cover damage, deterioration or malfunction resulting from alteration, modification, improper or unreasonable use or misuse, neglect, exposure to excess moisture, fire, improper packing, lightning, power surges, or other acts of nature. This limited warranty does not cover damage, deterioration or malfunction resulting from repairs attempted by anyone unauthorized by Victron Energy to make such repairs. Non-compliance with the instructions in this manual will render the warranty void. Victron Energy is not liable for any consequential damages arising from the use of this product. The maximum liability of Victron Energy under this limited warranty shall not exceed the actual purchase price of the product.

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