Eliminates electrical noise
Reduces high-frequency noise and disturbances that affect PLCs, drives, and sensitive instrumentation.
Isolation & Ultra-Isolation Transformers
Isolation & Ultra-Isolation Transformers for Clean, Protected Power
Voltaire isolation transformers provide galvanic isolation, noise suppression, and harmonic reduction for sensitive equipment including CNC/VMC machines, medical systems, IT racks, and laboratory instruments. Designed as industrial-grade isolation transformer solutions, they deliver clean, protected power for mission-critical loads.
Isolation TransformerUltra-Isolation TransformerGalvanic Isolation
The Principle
What an isolation transformer actually does
An isolation transformer transfers power between two windings that have no metallic connection to each other. Power crosses the magnetic field; nothing else does. That property — galvanic isolation — is the entire product, and it produces three distinct benefits that get confused with one another constantly.
The first is safety. With no shared conductive path back to the supply's earth, a single contact with a secondary conductor does not complete a circuit. It takes two simultaneous faults to create a hazardous path, which is why isolation transformers appear in wiring codes for wet locations, test areas, and medical environments rather than only in noise-control specifications.
The second is a clean earth reference. The secondary is a separately derived system, so a fresh neutral-to-earth bond is established at the transformer. Every piece of equipment downstream then sits on a local, defined earth rather than inheriting the neutral displacement and circulating earth currents that build up across a large plant's earthing system. In a great many industrial specifications, this — not noise — is the actual reason the transformer was called for.
The third is noise rejection, and this is where the product splits into two grades. Disturbances that appear equally on line and neutral relative to earth don't need a conductive path to get through: they couple capacitively across the gap between the windings. A standard isolation transformer reduces this incidentally, through physical separation. An ultra-isolation transformer attacks it deliberately, with earthed electrostatic shields between the windings that divert the coupled current to earth before it reaches the secondary.
What it does not do is regulate voltage. A 1:1 isolation transformer passes your input voltage through unchanged, sags and surges included. If the supply itself is unstable, that is a servo stabilizer's job — and in plants on a poor grid feed, the two are routinely installed in series, the stabilizer correcting amplitude and the isolation transformer handling isolation and noise.
Choose Your Variant
Which isolation transformer do you need?
Two questions decide it, and they're independent of each other.
First: what problem are you solving?
If the requirement came out of an electrical consultant's earthing design, a safety code, or a need for a separately derived neutral — a standard isolation transformer is what was intended, and paying for shielding you don't need is just overspending. If it came out of a measured or observed problem — instrumentation drifting without a process cause, controllers resetting intermittently, communication or encoder errors, equipment that misbehaves only when a large drive nearby starts — that symptom profile is common-mode noise, and only an ultra-isolation transformer will fix it.
Second: where does it sit in the installation?
At or near one piece of equipment — a bench, an instrument, a control panel — it's a single-phase unit, and the specification is dominated by inrush and load linearity rather than by capacity. At a distribution board, isolating a machine group, a line, or an area, it's a three-phase unit, where winding configuration, phase balance, and harmonic loading all enter the sizing calculation.
Isolation Grade
Standard
Galvanic separation, done properly.
Isolation Grade
Ultra-Isolation
When the problem is noise, not voltage.
Phase Configuration
Single Phase
Bench, lab, and instrument-level isolation.
Phase Configuration
Three Phase
Feeder-level isolation for plant loads.
Why Isolation & Ultra-Isolation
Why use an isolation transformer?
A Voltaire isolation transformer creates a dedicated, electrically separated supply for critical loads. It breaks direct electrical continuity with the grid while attenuating noise, spikes, and transients.
Protects against spikes & transients
Buffers voltage spikes, surges, and switching transients coming from the upstream network.
Breaks the direct electrical path
Provides galvanic isolation between input and output, cutting direct conductive paths and improving safety.
Prevents shock hazards
Helps in reducing touch potential and leakage-related risks in specialized installations.
Reduces common-mode noise
Electrostatic shields and optimized winding geometry reduce common-mode and differential-mode noise.
Improves overall power quality
Delivers cleaner, more stable power to precision loads, extending equipment life and reliability.
Technical Specifications
Isolation transformer specifications
Standard ratings and configuration options for Voltaire isolation and ultra-isolation transformers. Project-specific ratings and constructions are available on request.
| Ratings | 1 kVA – 500 kVA |
|---|---|
| Insulation class | Class F or Class H |
| > Efficiency | > 96% typical |
| Core & winding | CRGO core with copper windings (other options on request) |
| Electrostatic shields | Single or multiple shields available for noise attenuation |
| Construction | Isolation / ultra-isolation depending on application criticality |
| Mounting | Floor-mounted / panel-integrated designs as per project requirement |
Recommended Applications
Recommended for sensitive & high-value equipment
Voltaire isolation transformers are deployed wherever clean, isolated power is essential for safety, precision, and uptime.
CNC, VMC & Laser MachinesMedical Imaging & DiagnosticsIT Racks & ServersTelecom & Data CentersLaboratory InstrumentsPrecision Measurement & Testing
Sizing
How isolation transformers are sized (and how sizing goes wrong)
Adding up nameplate ratings and buying the next kVA size up is the most common sizing method — and the most common cause of a transformer that runs hot, dips under load, or ages early. Three factors sit outside that arithmetic.
Inrush
Equipment with switch-mode power supplies, capacitor-input rectifiers, or motor loads draws several times its running current at start-up. A transformer sized tightly to steady-state load produces a visible voltage dip every time that equipment starts.
Harmonics
Non-linear loads — drives, SMPS, rectifiers, LED lighting at scale — draw current with substantial harmonic content, producing eddy-current and stray losses that heat the windings beyond what RMS current predicts. The transformer needs derating, or an appropriate K-factor rating.
Phase imbalance
On three-phase units, significantly unbalanced downstream loading produces neutral current and uneven winding heating, and the unit will not deliver nameplate performance.
We do this sizing as part of quoting rather than leaving it to the buyer. Send the load schedule with the non-linear proportion identified — and the single-line diagram if you have one — and we'll confirm capacity, configuration, and lead time.
Common Questions
Isolation transformer FAQs
No. It passes input voltage through unchanged at a 1:1 ratio, including sags and surges. Voltage correction is a servo stabilizer's function; the two are commonly installed together where both problems exist.
Talk to an Engineer
Get detailed specs for Voltaire isolation transformers.
Request detailed ratings, wiring diagrams, mechanical dimensions, and test reports for Voltaire isolation and ultra-isolation transformers. Ideal for consultants, OEMs, and procurement engineers specifying clean power solutions for sensitive loads.
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For customized ratings or OEM-specific designs, speak to our engineering team.