20 kVA Three-Phase Isolation Transformer
Three-phase 20 kVA isolation transformer providing complete galvanic isolation for sensitive industrial equipment. Features low leakage inductance and excellent EMI suppression.
Ref. ISO-20-3PH · Lead time 3–4 weeks · Made to order from Hapur
See full engineering specification & variants
Key Features
Recommended For
Specifications
| Specification | Value |
|---|---|
| Capacity | 20 kVA |
| Primary Voltage | 415V, 3-Phase |
| Secondary Voltage | 415V, 3-Phase |
| Frequency | 50/60 Hz |
| Voltage Regulation | ±2% |
| Cooling | both air and oil cooled |
| Weight | 420 kg |
| Warranty | 3 years |
Reading the specification
What these numbers mean for your installation
A datasheet tells you what the unit does. This is what each figure changes about how you specify, feed and site it — worked out for the 20 kVA specifically, not the range in general.
28 A per phase
20 kVA at 415 V three-phase is about 28 A. Isolation transformers are sized on connected load, not on the diversified figure — total the nameplate rating of everything downstream rather than a metered average.
±2%
±2% describes how far output sags between no load and full load. It is not voltage correction: an isolation transformer passes incoming fluctuation straight through. If your supply itself is unstable, this belongs downstream of a servo stabilizer, not instead of one.
Standard 1:1 galvanic
A 1:1 galvanic barrier breaks the conductive path between supply and load, giving you a separately derived neutral and a clean local earth reference. That solves earth-loop and leakage-trip problems; it is not primarily a noise-filtering device.
Sizing Guide
When is 20 kVA the right choice?
20 kVA three-phase is the smallest rating that suits machine-level isolation. A single CNC machining centre with its drives and control transformer sits between 8 and 15 kVA; a laser cutter or EDM with its chiller lands in the same band. This rating covers one machine plus ancillaries with margin for the inrush that VFD-driven spindles produce at startup. It is also the standard choice for a medical imaging room — a CT or MR console and gantry supply, where a separately derived neutral is a code requirement rather than an optimisation. Above two machines, or where a shared bus feeds several drives, step to 50 kVA.
Before you order
Where 20 kVA goes in, and what the site needs
Typical installations
We supply 20 kVA most often into single cnc machining centres with drives, laser cutters / edm machines with chillers, medical imaging consoles (ct/mr gantry supply) and precision manufacturing cells, alongside industrial testing equipment and sensitive electronic systems. What separates those sites is the sensitivity of what sits downstream, not the kVA. The same rating protects a production machine and a metrology bench, but the earthing arrangement and shield termination that each needs are not the same, and getting that wrong wastes the transformer.
Site preparation
At 420 kg you need a pallet truck at minimum and a level, load-spreading base. Check the route for ramp gradients — a hydraulic truck carrying 420 kg will not climb much of one. Leave working clearance on the terminal side for cable entry and inspection. Sustained ambient above 45 °C, or an enclosed room without cross-ventilation, requires derating — send us the room conditions and we will confirm the rating still holds where you intend to put it.
Adjacent ratings
If 20 kVA is not the right size
Sizing rarely lands exactly on a catalogue rating first time. These are the ratings either side of it in the same range — compare the specification before you commit.
10 kVA Single-Phase Isolation Transformer
High-isolation single-phase transformer for sensitive electronic equipment protection.
View specificationUltra-Isolation Transformer50 kVA Three-Phase Ultra-Isolation Transformer
Industrial three-phase ultra-isolation transformer with advanced noise suppression.
View specificationAlso in the transformer range
Different equipment rather than a different size — often specified alongside this on the same project.
25 kVA Distribution Transformer (11kV)
Standard distribution transformer for 25 kVA load, 11kV primary voltage.
View specificationDistribution Transformer63 kVA Distribution Transformer (11kV)
63 kVA distribution transformer for medium-scale power distribution.
View specificationDistribution Transformer100 kVA Distribution Transformer (33kV)
Heavy-duty 100 kVA distribution transformer for medium-voltage grid integration.
View specificationEngineering detail on this configuration
The isolation transformer pages carry the full design rationale, comparison tables and application notes behind this SKU.
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