Victron Autotransformer

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Quantity Image Name Price
Autotransformer 120/240V-100A
Autotransformer 120/240V-100A
For step up, step down and split phase balancing
$1,131.00 Back Order
Autotransformer 120/240VAC-32A
Autotransformer 120/240VAC-32A
For step up, step down and split phase balancing
$888.00 Back Order

The Autotransformer: for step up, step down and split phase balancing

An autotransformer can be used for step up, step down and split phase output balancing purposes. While the step up and step down functions are fairly straightforward, split phase output balancing may require some more attention.

Consider for example a 30A 120/240V split phase supply. The supply could be the grid, a generator or two stacked inverters. Some of the loads connected are 240V, others are 120V. On each 120V leg the load should not exceed 30A. The problem is that as soon as 120V loads are connected, the two legs will show a different current. This is because the 120V loads on the two legs will never be balanced. A 120V 1200W hairdryer, for example, will draw 10A from one leg. A 120V washing machine could even draw in excess of 20A from one leg. Between the two legs the difference in current, or current unbalance, will therefore often be 20A or more. This means that the 30A supply will not be used up to its full potential. By the time one leg draws 30A, the other leg may be drawing no more than 10A, and increasing the 240V load, for example, will result in an overload of one leg while the other leg still has spare capacity.

Theoretically, the total power that can be drawn from a 30A 120/240V supply is 30 x 240 = 7,2 kVA. In case of 20A unbalance, the practical maximum will be 30 x 120 + 10 x120 = 4,8kVA, or 67% of the theoretical maximum.

The solution is an Autotransformer.

By leaving the neutral of the split phase supply unused, and connecting an Autotransformer to create a new neutral, as shown in figure 1, any load unbalance is ‘absorbed’ by the Autotransformer. In case of a 30A supply, the load can be increased to 7,2kVA, and a 20A load unbalance will result in one leg supplying 40A, and the other leg 20A. The 20A difference will flow through the neutral and the windings of the Autotransformer. The current through both 120V wires of the split phase supply will be 30A

 

Ground relay for use with Multi or Quattro Inverter/Chargers included

When operating in inverter mode, the neutral output of the inverter/charger must be connected to ground to guarantee proper functioning of a GFCI. In case of a split phase supply the neutral must be grounded. For this purpose a grounding relay is built in the autotransformer’s enclosure. The relay is controlled by the 230/240V Multi or Quattro. (The internal grounding relay in the 230/240V Multi or Quattro must be disabled)

 

Temperature protected

In case of overheating, the Autotransformer is disconnected from the supply. Reset is manual.

 

An alternative to stacked inverters

The alternative to stacking two 120V inverters to provide a 120/240V split phase supply is a 240V inverter with an additional Autotransformer.

Two stacked 120V 3kVA inverters will supply up to 25A to each 120V leg. If the load on one leg is less than 25A, the maximum load on the other leg is still limited to 25A.

One 240V 5kVA inverter with a 32A Autotransformer will supply up to 21A of balanced load to each 120V leg. Fewer loads on one leg will however result in more power being available on the other leg, with a maximum unbalance of 32A. Therefore the load can be up to 38,5A on one leg if the load is not more than 3,5A on the other leg (maximum unbalance: 38,5 – 3,5 = 35A). If load unbalance is to be expected, a lower power 240V inverter with autotransformer will therefore be preferable to the stacked inverter solution.

(VIC-AutoTransformer)

Victron Energy Limited Warranty Policy


Victron Energy warrants its products to be free from defects in workmanship and materials for a period of 5 years from the date of purchase by the end user, with a maximum of 66 months from the Victron Energy invoice date. Exceptions on this are: lead acid batteries; 2 years from date of purchase by the end user, with a maximum of 30 months from the Victron Energy invoice date, Lithium-ion batteries; 3 years from date of purchase by the end user. In addition to this proof of correct battery usage is required when making a battery warranty claim.


During this period, Victron Energy will, at its option, repair or replace the defective product free of charge. The warranty does not include performing or reimbursing de‐installation, transportation and re‐installation. This warranty will be considered void if the unit has suffered any physical damage or alteration, either internally or externally, and does not cover damages arising from improper use like:
• Reverse of battery polarity.
• Inadequate connection.
• Mechanical shock or deformation.
• Contact with liquid or oxidation by condensation.
• Use in inappropriate environment (dust, corrosive vapor, humidity, high temperature, biological infestation...).
• Breakage or damage due to lightning.
• Connection terminals and screws destroyed or other damages, like overheat, due to insufficient tightening.
• For any electronical breakage except due to lightning (reverse polarity, over‐voltage due to external cause), the state ofthe internal control diode and of the inputs/output X and Y capacitors determine the warranty.


This warranty will not apply where the product has been misused, neglected, improperly installed, or repaired by anyone else than Victron Energy or one of its authorized Qualified Service Partners. In order to qualify for the warranty, the product must not be disassembled or modified.


Repair or replacement are our sole remedies and Victron Energy shall not be liable for damages, whether direct, incidental,special, or consequential, even caused by negligence or fault.


Victron Energy owns all parts removed from repaired products. Victron Energy uses new or reconditioned parts made by various manufacturers in performing warranty repairs and building replacement products. If Victron Energy repairs or replaces a part of a product, its warranty term is not extended. In case of replacement the new component has a warranty of 6 months, without effect on the initial warranty period. All remedies and the measure for damages are limited to the above. Victron Energy shall in no event be liable for consequential, incidental, contingent orspecial damages, even if having been advised of the probability of such damages. Any and all other warranties expressed or implied arising by law, course of dealing, course of performance, usage of trade or otherwise, including but not limited to implied warranties of merchantability and fitness for a particular purpose, are limited in duration to a period of two (2) years from the date of purchase.


Life Support Policy
As a general policy, Victron Energy, does not recommend the use of any of its products in life support applications where failure or malfunction of the Victron Energy's product can be reasonably expected to cause failure of the life support device or to significantly affect its safety or effectiveness. Victron Energy does not recommend the use of any of its products in direct patient care. Victron Energy will not knowingly sell its products for use in such applications unless it receives in writing assurances satisfactory to Victron Energy that the risks of injury or damage have been minimized, the customer assumes all such risks, and the Liability of Victron Energy is adequately protected under the circumstances.


As a product requires service, it must be brought back to the place of purchase. In case no contact can be taken with the merchant, or if he is either unable or not allowed to provide service, direct contact should be taken with Victron Energy.


Warranty on Repairs
The warranty period on products or on printed circuits boards repaired by Victron Energy as well as on printed circuit boards for replacement is 6 months from delivery by Victron Energy.


Transport
It is the responsibility of the sender to sufficiently package these products. The transport must be organized in a way to avoid any damage, especially when a single unit or heavy unit is sent.


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For Australia only
Our goods come with guarantees that cannot be excluded under the Australian Consumer Law. You are entitled to a replacement or refund for a major failure and compensation for any other reasonably foreseeable loss or damage. You are also entitled to have the goods repaired or replaced if the goods fail to be of acceptable quality and the failure does not amount to a major failure.


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