‘K’ Rated Isolation Transformer are designed to reduce the heating effect of harmonic currents produced by non-linear loads. A standard transformer is design based on resistive load calculation and will overheat and fail prematurely when connected to Non - linear loads.
K- Factor is defined as a ratio between the additional losses due to harmonics and the resistive losses at 50 Hz.Transformers with a rated K-factor of 4, 7, 13, 20 and 30 are available. The ANSI/ IEEE C57. 110 has derived a system of weighing how much harmonic load currents a Transformer can handle without exceeding its maximum temperature rise level.
A ‘K’ factor of 1 indicates no harmonics, while a K factor of 50 is the harshest harmonic environment possible. Typically a K Factor of 13 is sufficient for most applications. K factor must be determined to calculate the right size transformer that is needed.
| Parameter | Description |
| KVA Rating – Three Phase | 10 to 2500 KVA |
| Cooling | Air & Oil Cooled. |
| Impedance | 3 - 4 % or as required. |
| Input Voltage | 380 / 400 / 415 / 440 - 3 Phase or as required. |
| Output Voltage | 380/400/415 / 200 / 220 V 3 Phase or as required. |
| Input / Output configuration | Dyn11 standard / Zig Zag & other Vector Group on request. |
| Construction | Double wound, Common core, Varnish and vacuum impregnated. |
| Winding | Electrolytic grade Copper / Aluminum |
| Neutral Conductor Rating | 200 % |
| Frequency | 50 +/- 3 Hz / 60 Hz on request. |
| Insulation Class / Level | H Class / 180 deg. C |
| Maximum temperature rise | 115 deg. C. |
| Efficiency | Better than 96 %. |
| Regulation | 2 – 4 % or as required. |
| Common mode Noise Attenuation | 60 – 80 dB / other on request. |
| High Voltage Breakdown Test | 2.5 KV for one Minute Between windings and Earth. |
| Termination Type | Terminal Board / Stud – Bolts / Bus Bar |
| Enclosure Protection Class | IP21 / As per Requirement. |
| Environment | Temperature Range 0 to 45 °C. Suitable for indoor Tropical use 90% RH (non-condensing). |
| Reference Standard | IS2026 / IS11171 UL-1561 |
| Life Expectancy | 25 Years |