OCF24 / OCF36 / OCF52 / OCF72 — outdoor current transformers, 24–72.5 kV
OCF is a series of dry-type current transformers for outdoor installation at voltages from 24 to 72.5 kV. The aluminium base and the cast cycloaliphatic resin housing withstand aggressive and polluted environments. They are used in outdoor switchyards of substations, at metering points on overhead lines and at collector substations of wind and solar farms.
- OCF24-1 / -2
- 27.5/50/150 kV; up to 400 / 1250 A; Ith 36 / 60 kA for 1 s; creepage 690 / 860 mm; 18 / 40 kg
- OCF36-2 / -3 / -4
- 36/70/200 kV; up to 1250 / 3200 / 3200 A; Ith up to 60 kA; creepage 1050–1120 mm (OCF45-3 — 1300 mm); 45 / 65 / 105 kg
- OCF52-2 / -3 / -4
- 52/95/250 kV; up to 400 / 3200 / 3200 A; Ith 40–60 kA; creepage 1278–1500 mm; 55 / 80 / 130 kg
- OCF72-3 / -4
- 72.5/140/325 kV; up to 1250 / 3200 A; Ith 40 / 60 kA; creepage 2250 mm; 115 / 213 kg
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
The OCF series covers voltages from 24 to 72.5 kV. All transformers are dry-type, with an aluminium base and a cast cycloaliphatic resin housing, and operate at −50…+50 °C. Frequency is 50/60 Hz, dynamic current up to 2.5 Ith. A dual transformation ratio is obtained by tapping the secondary winding or by switching the primary. Accuracy classes under IEC are 0.1–PX, with 5PR and 10PR also available for the larger models, under CSA 0.3–10L, and under IEEE as applicable. Standards are IEC 61869-2, CSA C61869-2 and IEEE C57.13.
The 24 kV class includes OCF24-1 and OCF24-2. OCF24-1 is compact: insulation up to 27.5/50/150 kV, primary current up to 400 A, short-time thermal current up to 36 kA for 1 s, one core, creepage distance 690 mm (arcing distance 293 mm), mass about 18 kg. OCF24-2 is rated for 1250 A and 60 kA, has 1–3 cores, a creepage distance of 860 mm and a mass of 40 kg. The 36 kV class has insulation up to 36/70/200 kV. OCF36-2 is rated for 1250 A, with creepage 1050 mm and a mass of 45 kg. OCF36-3 is rated for 3200 A, with creepage 1120 mm (arcing distance 425 mm) and a mass of 65 kg, and as an option the creepage distance is extended to 1300 mm in the OCF45-3 version. OCF36-4 is also rated for 3200 A and has a mass of 105 kg. Short-time thermal current in this class reaches 60 kA for 1 s.
The 52 kV class has insulation up to 52/95/250 kV. OCF52-2 is rated for 400 A and 40 kA, with creepage 1278 mm and a mass of 55 kg. OCF52-3 is rated for 3200 A and 60 kA, has 1–2 cores, creepage 1500 mm and a mass of 80 kg. OCF52-4 is also rated for 3200 A and 60 kA, with 1–3 cores, creepage 1400 mm and a mass of 130 kg. In the 72.5 kV class the insulation is up to 72.5/140/325 kV. OCF72-3 is rated for 1250 A and 40 kA and has a mass of 115 kg. OCF72-4 is rated for 3200 A and 60 kA, has 1–3 cores, creepage 2250 mm, arcing distance 790 mm and a mass of 213 kg.
The secondary terminal uses a polyamide PG21 cable gland for cable Ø 10–18 mm; a nickel-plated brass PG21 or a 1″ NPT adapter can be fitted as an option. The primary connection is made of tinned copper or to the customer's specification. The transformers are used in outdoor switchyards of 10–66 kV substations, at commercial metering points on overhead lines, for connecting outdoor reclosers and circuit breakers, and at collector substations of wind and solar farms.
Technical specifications
| OCF24-1 / -2 | 27.5/50/150 kV; up to 400 / 1250 A; Ith 36 / 60 kA for 1 s; creepage 690 / 860 mm; 18 / 40 kg |
|---|---|
| OCF36-2 / -3 / -4 | 36/70/200 kV; up to 1250 / 3200 / 3200 A; Ith up to 60 kA; creepage 1050–1120 mm (OCF45-3 — 1300 mm); 45 / 65 / 105 kg |
| OCF52-2 / -3 / -4 | 52/95/250 kV; up to 400 / 3200 / 3200 A; Ith 40–60 kA; creepage 1278–1500 mm; 55 / 80 / 130 kg |
| OCF72-3 / -4 | 72.5/140/325 kV; up to 1250 / 3200 A; Ith 40 / 60 kA; creepage 2250 mm; 115 / 213 kg |
| Housing | aluminium base, cycloaliphatic resin |
| Cores | 1–3 |
| Temperature | −50…+50 °C |
| Standards | IEC 61869-2, CSA C61869-2, IEEE C57.13 |
Replacement for
ТОЛ-35, ТФЗМ-35А, ТЛК-35, ТОЛ-10 (outdoor), ТВЛМ-10
selected by purpose and main parameters, please confirm with our manager
Request a price and lead time
OCF24 / OCF36 / OCF52 / OCF72 — outdoor current transformers, 24–72.5 kV. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Questions and answers
Which insulation levels does the OCF series have?
OCF24 has insulation up to 27.5/50/150 kV, OCF36 up to 36/70/200 kV, OCF52 up to 52/95/250 kV and OCF72 up to 72.5/140/325 kV.
What are the highest primary current and short-time thermal current?
The OCF36-3, OCF36-4, OCF52-3, OCF52-4 and OCF72-4 models are rated for primary current up to 3200 A. Short-time thermal current reaches 60 kA for 1 s.
Which standards do the transformers comply with and what temperature range do they cover?
They comply with IEC 61869-2, CSA C61869-2 and IEEE C57.13 and operate at −50…+50 °C.
Similar equipment from other manufacturers
