Victron Energy

Victron Energy Autotransformer 120/240V 100A, Step-Up, Step-Down & Split-Phase Balancing, for MultiPlus & Quattro, ITR000100102

Victron Energy Autotransformer 120/240V 100A, Step-Up, Step-Down & Split-Phase Balancing, for MultiPlus & Quattro, ITR000100102

πŸ”€ 120V ↔ 120/240V Step-Up & Step-Down|βš–οΈ Split-Phase Balancing|πŸ”Œ 100A Breaker Built In|πŸ›‘οΈ 5-Year Victron Warranty
Price: $509.15
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Price: $509.15
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  • πŸ‡ΊπŸ‡ΈFree ShippingContiguous 48 states
  • πŸ›‘οΈ5-Year WarrantyVictron limited warranty
  • πŸ”€Step-Up & Step-Down120V ↔ 120/240V
  • βš–οΈLoad BalancingSplit-phase legs
  • πŸ”Œ100 A Breaker IncludedTwo-pole input MCB
  • πŸ“žReal Human SupportSystem design help

Victron Energy Autotransformer 120/240V 100A (ITR000100102): a toroidal autotransformer that steps 120V up to 120/240V split-phase, steps split-phase down to 120V, and balances unequal loads on the two legs. Pair it with a 120V Victron MultiPlus, MultiPlus-II or Quattro to power 240V well pumps, A/C and other split-phase loads from a single inverter/charger, or let a 120/240V generator or shore supply feed a 120V inverter/charger using power from both legs. A built-in 100 A two-pole breaker doubles as the on/off switch, a ground relay controlled by the inverter/charger handles neutral-ground bonding, and temperature protection shuts it down if it overheats. This is the current 2026 revision of Victron's 100 A model. Backed by Victron's 5-year limited warranty.

100 A240V feed-through
45 ANeutral, continuous
55 ANeutral, 30 minutes
120/240 VSplit-phase, 50/60 Hz

Ratings from Victron's 2026 manual for the 50 A and 100 A autotransformers, at 40Β°C (104Β°F).

⚑ Is It Right for Your System?

Built for 120V and 120/240V split-phase systems with Victron inverter/chargers. Common uses:

  • Off-grid homes & cabins
  • 240V well pumps & A/C
  • RVs & boats on 50 A shore
  • Generator balancing
  • Backup power
πŸ“ Quick check before you order:
  • You have a Victron MultiPlus, MultiPlus-II or Quattro, or a split-phase generator or shore supply to balance.
  • Your 240V loads stay within 100 A feed-through, and the imbalance between legs (neutral current) stays within 45 A continuous (55 A for 30 minutes).
  • You understand it doesn't provide isolation; it's an autotransformer, not an isolation transformer.
  • You'll mount it indoors or in a compartment (IP21), vertically, with 10 cm (4 in) of clearance.
  • Plan for AC cabling (terminals take up to 35 mmΒ² / AWG 2) and a control cable for the ground relay from your inverter/charger.
  • Need UL? Victron doesn't list UL certification for this autotransformer. Call us if your inspector needs specific paperwork.
Not sure? Tell us your inverter, loads and power sources, and we'll confirm the right setup before you buy.

Why Choose a Victron Autotransformer

πŸ”€

Step-Up

Make 120/240V split-phase from a single 120V inverter/charger to run 240V loads like well pumps and A/C.

⬇️

Step-Down

Let a 120/240V generator or 50 A shore supply feed a 120V inverter/charger using power from both legs.

βš–οΈ

Load Balancing

Absorb leg imbalance on split-phase generators or stacked inverters so neither leg is overloaded.

πŸ”Œ

100 A Breaker Built In

A two-pole input breaker protects the unit and doubles as the on/off switch.

🌍

Ground Relay

A built-in neutral-ground bonding relay is switched by the inverter/charger for correct grounding on and off grid.

🌑️

Temperature Protection

The fan runs when warm, and the unit disconnects and shows a red LED if it overheats.

πŸ”§ What It Does

Mode Example
Step-up One 120V MultiPlus or Quattro powering 120/240V split-phase loads
Step-down A 120/240V generator or shore supply feeding a single 120V inverter/charger
Balancing Evening out unequal loads on a split-phase generator or stacked inverters
Ground relay Neutral-ground bond switched by the inverter/charger (24 V signal)

Victron's system schematics (AT-1 to AT-5) on the product page show typical wiring with Quattro and MultiPlus inverter/chargers.

πŸ“¦ What's Included & What You'll Need

  • Victron Energy Autotransformer 120/240V 100AVictron Autotransformer 120/240V 100APart number ITR000100102
  • 100 A Two-Pole BreakerBuilt in (input breaker and on/off switch)
  • Wall Hanger & Cable GlandsIncluded, per Victron's manual
  • AC CablingNot included. Terminals take up to 35 mmΒ² / AWG 2
Plan to add: AC cabling and conduit (1-1/4-inch NPT fittings can replace the supplied glands), and the control cable for the ground relay. Ask us and we'll put together everything your install needs.

🧰 Installation Notes

🧲

MultiPlus & Quattro

Disable the inverter's internal ground relay (SW1) and keep the relay enabled in settings so the autotransformer handles bonding.

πŸ”

MultiPlus-II

Disable the ground relay in the MultiPlus-II settings when using the autotransformer's ground relay.

πŸ“

Mounting

Vertical mounting is preferred, indoors or in a compartment, with 10 cm (4 in) of clearance.

πŸ”„

Reset

If the breaker trips on overload or overtemperature, let it cool and cycle the breaker to reset.

πŸ›‘οΈ 5-Year Victron Limited Warranty

Years 1–5Victron limited warranty from the original end user's purchase date (max 66 months from Victron's invoice date)
Up to Year 10Optional extension to 10 years, sold through Victron's direct customers. Ask us about eligibility.

Warranty claims are made through the place of purchase, which is us. Victron's warranty doesn't cover physical damage or alteration, misuse (reversed polarity, poor or loose connections, liquid or condensation, lightning), improper installation, repairs by anyone other than Victron or an authorized repair centre, or the cost of removal, shipping and reinstallation. Full terms in Victron's warranty policy below.

πŸ“‹ Full Specifications

Autotransformer
Model / Part Number Victron Autotransformer 120/240V 100A / ITR000100102 (2026 revision)
Input / Output Voltage 120/240 V, 50/60 Hz
Max 240V Feed-Through Current 100 A
Neutral Current 55 A for 30 minutes; 45 A continuous (at 40Β°C / 104Β°F)
Input Breaker 100 A two-pole, included (also the on/off switch)
Ground Relay Built in, controlled by the inverter/charger (24 V signal)
Temperature Protection Fan when warm; disconnects with red LED on overheat
Isolation None (autotransformer)
Physical & Certifications
Transformer Type Toroidal
Terminals Screw terminals, 35 mmΒ² / AWG 2
Enclosure Aluminium, IP21 (indoor or compartment)
Weight 13.5 kg (29.8 lb)
Dimensions (H Γ— W Γ— D) 460 Γ— 214 Γ— 110 mm (18.1 Γ— 8.4 Γ— 4.3 in)
Certifications EN 60076, EN-IEC 60335-1, EMC; Victron doesn't list UL
Warranty 5-year Victron limited warranty

πŸ“„ Manuals & Downloads

🌐Victron Product PageAutotransformersVICTRON β†—πŸ“˜Owner's ManualAutotransformer 50A & 100A (PDF)PDF β†—πŸ“ŠOnline ManualAutotransformer 50A & 100A, full specsVICTRON β†—πŸ“Dimension DrawingAutotransformer 50A & 100A (PDF)PDF β†—πŸ”ŒStep-Up Schematic120V to 240V with a Quattro 120V (PDF)PDF β†—πŸ“œVictron Limited WarrantyFull warranty policy (PDF)PDF β†—

Victron doesn't publish a full box contents list. Manuals, drawings and schematics above link straight to Victron.

❓ Common Questions

Can I run 240V loads from a single 120V MultiPlus or Quattro?
Yes. In step-up mode the autotransformer creates 120/240V split-phase from a single 120V inverter/charger, within its 100 A feed-through and 45 A continuous neutral (imbalance) rating.
Can I use a 240V generator with a 120V inverter/charger?
Yes. In step-down mode it lets a 120/240V generator or shore supply feed a single 120V inverter/charger, using power from both legs.
Does it provide isolation?
No. It's an autotransformer, so the input and output aren't galvanically isolated.
What happened to the 32 A rating?
That's Victron's older 32 A model. This 100 A revision (ITR000100102) is rated for 55 A of neutral current for 30 minutes and 45 A continuously.
Do I need to change settings on my inverter/charger?
Yes. With a MultiPlus or Quattro, disable the internal ground relay with SW1 and keep the relay enabled in settings; with a MultiPlus-II, disable the ground relay in settings.
Is it UL listed?
Victron doesn't list UL certification for the autotransformer. Call us if your inspector needs specific paperwork.
How does the warranty work?
Victron covers it for 5 years from the original end user's purchase date. Warranty claims go through the place of purchase, so contact us and we'll handle it with Victron.

Questions About Your Setup? Ask Us First.

Tell us your inverter/charger, loads and power sources, and we'll confirm the autotransformer setup before you order.

πŸ“ž Call 833-664-7433πŸ“§ Email Us