11 KV / 22 KV / 33 KV Distribution Transformers
Oil-cooled and cast-resin distribution transformers for 11 KV, 22 KV and 33 KV incomers, stepped down to plant LT voltage and rated to your connected load.
About 11 KV / 22 KV / 33 KV Distribution Transformers
A distribution transformer takes the 11 kV, 22 kV or 33 kV supply from the electricity board and steps it down to 433 V, three-phase, for your plant or building. Because it stays energised round the clock while load varies through the day, it is designed for low iron (no-load) loss and good efficiency at part load.
Microtech supplies distribution transformers from Schneider Electric, CG Power (Crompton Greaves), Power Star and Globe Rectifiers. Oil-immersed units are built to IS 1180, which covers three-phase ratings up to 2500 kVA on systems up to 33 kV, and sets maximum total losses at 50% and 100% load for five energy-efficiency levels. Schneider's Minera ground-mounted oil-immersed range goes up to 2.5 MVA at 36 kV; larger power transformers follow IS 2026. Cast-resin dry-type units suit indoor substations and fire-sensitive areas where oil is not acceptable.
We size the transformer to your connected load with growth margin, select the efficiency level, tap range and vector group, and supply it with the HT and LT switchgear for the substation.
Key specifications
| Primary voltage | 11 kV, 22 kV or 33 kV class |
|---|---|
| Secondary voltage | 433 V, 3-phase, 50 Hz |
| IS 1180 preferred 3-phase ratings | 16, 25, 63, 100, 160, 200, 250, 315, 400, 500, 630, 800, 1000, 1250, 1600, 2000, 2500 kVA |
| Energy efficiency | IS 1180 Levels 1 to 5 (maximum total loss at 50% and 100% load) |
| Recommended impedance (IS 1180) | 4.5% up to 630 kVA; 5% for 800–1250 kVA; 6.25% for 1600–2500 kVA |
| Construction | Oil-immersed; cast-resin dry-type for indoor use |
| Tap changing | Off-circuit tapping or on-load tap changer |
| Temperature rise (IS 1180-1) | Winding/top oil 40/35 °C up to 200 kVA; 45/40 °C for 250–2500 kVA |
Features & benefits
- Built and tested to IS 1180 or IS 2026 by the manufacturer
- Choice of energy-efficiency level to suit running hours and loss cost
- Copper or aluminium windings as specified
- IS 1180 fittings include liquid level gauge, pressure relief device and, above 1000 kVA, Buchholz relay
- Off-circuit or on-load tap changing to hold LT voltage
- Supplied with matching HT VCB/RMU and LT panel when required
Where it’s used
- Factories and industrial plants
- Hospitals and institutional campuses
- Commercial complexes and malls
- Residential townships and housing societies
- Cold storages and rice mills
- Solar plant evacuation
Standards & compliance
11 KV / 22 KV / 33 KV Distribution Transformers — FAQs
What size transformer do I need?
We work from your connected load, diversity and expected growth, then pick the next IS 1180 standard rating with margin. A load list or recent electricity bills with maximum demand is enough for a first estimate.
What are IS 1180 energy efficiency levels?
IS 1180 sets maximum total losses for each kVA rating at 50% and 100% load, in five levels. A higher level means lower losses and lower running cost, at a higher purchase price. We help you compare them against your operating hours.
Oil-immersed or dry-type?
Oil-immersed transformers are the usual choice outdoors. Cast-resin dry-type transformers are used indoors, in basements and in fire-sensitive buildings where oil is not acceptable.
Do you supply 33 kV transformers in Uttar Pradesh?
Yes. We supply 11 kV, 22 kV and 33 kV distribution transformers across Uttar Pradesh and neighbouring states, along with the HT and LT switchgear, installation and testing.
