Transformers
Distribution, dry type, oil immersed, pad mounted and power transformers, quoted against the rating, the voltages and the loss rules at the destination.
kVA · MVAIEC 60076 · IEEE C57.12
Transformers · Substations · Switchgear
Transformer, substation and switchgear sourcing
Daverlan is an independent sourcing company. Send a rating, a single line diagram or a full bill of materials. We check it for gaps, source against it, and set the quotations out so scope, standard and delivery terms can be compared.
IEC, EN and IEEE specifications · Ratings in kVA and MVA · English and German
- Equipment
- Transformers, substations, switchgear
- Rating basis
- kVA and MVA
- Specification
- IEC, EN or IEEE
What we source
Four families · specified by rating, voltage and site
Substations
Compact, secondary and package substations, with the transformer, the medium voltage switching and the low voltage board specified as one arrangement.
PrefabricatedIEC 62271-202
Switchgear
Medium voltage switchgear, ring main units and low voltage switchboards, specified by rated voltage, rated current, short circuit rating and insulation medium.
MV · LV · RMUIEC 62271-200 · IEC 61439
Protection and control
Circuit breakers, protection relays and control panels, selected against the protection scheme rather than bought as loose parts.
Breakers · relaysIEC 62271-100 · IEC 60255
Shown for illustration. Not a product of this company, and no stock or manufacturer relationship is implied. Full image credits
Who sends us requests
Six kinds of buyer, each arriving with a different starting document.
| Buyer | Usually arrives with | Start here |
|---|---|---|
| Electrical contractors | A rating and voltages from the design, and a date tied to the programme | Request a quote |
| EPCs and engineering firms | Equipment schedules, single line diagrams and specifications covering several packages | Upload the specification |
| Industrial facilities | Nameplate data of a unit being replaced, or a load increase to size against | Industrial facilities |
| Commercial and data centre teams | A redundancy scheme, transformer and LV board ratings, and indoor constraints | Data centres |
| Utilities and network operators | Network specifications and standard ratings, often for several units | Utilities and infrastructure |
| Equipment dealers | Ratings or models to source for their own customers | Request a quote |
How a request is handled
- 01
Review
The request is checked against a fixed set of fields. Gaps and contradictions are raised with you first.
- 02
Confirm
The standard, the loss rules and any restriction at the destination are confirmed, not assumed.
- 03
Source
Equipment is sourced against the specification rather than against one supplier's range.
- 04
Compare
Quotations are set out on one basis: scope, standard, documents, condition, delivery terms and validity.
- 05
Order
The order is placed against the agreed specification, with the documents the quotation lists.
What you can expect
- One request, several packages
- Transformers, switchgear and substations can sit in the same request.
- Gaps raised early
- Missing voltages, standards or dates are raised before a supplier sees the request.
- Comparable quotations
- Offers come back on the same basis, so the difference between them is visible.
- A plain no
- If a request is not something we can source well, we say so.
- New by default
- Surplus or refurbished units are considered only when you ask for them and their condition can be documented.
How manufacturers are chosen, and who is responsible for what
Find a transformer by rating
Standard ratings, with the full load current that sizes the low voltage side.
| Rating | Current at 400 V | Current at 433 V | Distribution | Dry type |
|---|---|---|---|---|
| 100 kVA | 144 A | 133 A | View | |
| 160 kVA | 231 A | 213 A | View | |
| 200 kVA | 289 A | 267 A | View | |
| 250 kVA | 361 A | 333 A | View | |
| 315 kVA | 455 A | 420 A | View | |
| 400 kVA | 577 A | 533 A | View | View |
| 500 kVA | 722 A | 667 A | View | View |
| 630 kVA | 909 A | 840 A | View | View |
| 800 kVA | 1155 A | 1067 A | View | View |
| 1000 kVA | 1443 A | 1333 A | View | View |
| 1250 kVA | 1804 A | 1667 A | View | View |
| 1600 kVA | 2309 A | 2133 A | View | View |
| 2000 kVA | 2887 A | 2667 A | View | View |
| 2500 kVA | 3608 A | 3333 A | View | View |
Currents are calculated as S / (√3 × V) and rounded. Impedance, dimensions, weight and declared losses belong to the unit offered and come with the quotation.
Standards and destinations
Specifications written to IEC and EN standards are accepted, and so are IEEE specifications for 60 Hz markets. Which standard governs at the destination, and whether the network operator adds its own requirements, is confirmed for each request rather than assumed.
Some destinations add rules of their own. In the EU and Great Britain, transformers within scope must meet the ecodesign loss limits, and in the EU new SF6 switchgear up to 24 kV may not be put into operation from 1 January 2026, with limited exemptions.
| Standard | Covers |
|---|---|
| IEC 60076 | Power transformers, with dry type transformers in part 11 |
| IEEE C57.12.00 | Liquid immersed distribution and power transformers, general requirements |
| IEEE C57.12.34 | Pad mounted, three phase distribution transformers, 10 MVA and smaller |
| IEC 62271-202 | Prefabricated substations, above 1 kV up to and including 52 kV |
| IEC 62271-200 | Metal enclosed AC switchgear, above 1 kV up to and including 52 kV |
| IEC 61439-1 and -2 | Low voltage switchgear and controlgear assemblies |
Applications
All industriesEach application is a different equipment chain.
Data centres
Redundancy decides how many transformers there are and how each is loaded.
Industrial facilities
Motor starting decides the rating more often than the running load.
Commercial buildings
Space, access and fire rules usually decide between dry type and liquid filled.
Renewable energy connections
Export duty and the network operator's protection requirements govern the arrangement.
Technical resources
Reference material, free to use and cite.
| Type | Title | Purpose | Link |
|---|---|---|---|
| Calculator | kVA and amps calculator | Convert a rating to the current that sizes the board | View |
| Reference | Transformer loss limits | The EU and GB tier 2 maximum losses for every rating in the tables | View |
| Guide | Transformer sizing guide | How a rating is decided, and what makes estimates wrong | View |
| Reference | Standards cross reference | Which standard governs which equipment, and what replaced what | View |
Have a specification, drawing or bill of materials?
Upload it once. Gaps are raised before it reaches a supplier.