Medium-voltage current transformers
Application and description
APPLICATION: These transformers are used to isolate measuring and protection devices from high voltage and to transform measured currents to a value suitable for measuring and protection devices. They are intended for installation in switchgear with voltages up to 38 kV. They supply ammeters, current circuits of electricity meters, protection relays and other devices. The transformers can operate continuously at currents up to 20% higher than rated, while still meeting the specified accuracy class.
DESCRIPTION: The main insulation of these transformers is epoxy resin. Their cores are made of high-quality cold-rolled grain-oriented magnetic steel. The secondary terminals are brought out into a separate terminal box that can be sealed. The transformers are made with 1, 2, 3 or more cores and the same number of independent secondary windings. The primary winding can be made in two sections, allowing the transformer to be primarily switchable. The designation 2x100A means that the transformer can be used for rated primary currents of 100A and 200A.
Burden and correct selection
EFFECT OF THE BURDEN ON THE SECURITY FACTOR AND ACCURACY LIMIT FACTOR OF CURRENT TRANSFORMERS: The standard values of the security factor and accuracy limit factor given by the manufacturer refer to the rated burden of the current transformer cores. If the rated burden is not connected to the secondary of the current transformer, the security factor (or accuracy limit factor) will change. For an exact calculation and for finding the right type of transformer, please refer to the contact page.
CORRECT SELECTION OF INSTRUMENT TRANSFORMERS: Three-system metering requires 3 current and 3 voltage instrument transformers rated for the voltage level of the network where the metering takes place. It is important that the transformation ratio and the burden of the instrument transformers are determined as accurately as possible, so that the metering is as precise as possible. The primary current of the current transformers is the line current calculated from the rating of the power transformer in front of which the unit is installed, rounded up to the nearest higher standard value. Since the power transformer itself is not always loaded with its rated power, the rated primary current of the current transformers should be determined as realistically as possible.
Filters
Support-type current transformers 12-38 kV
Voltage: 12 kV, 24 kV, 38 kV | Mounting: Indoor / Outdoor | Insulation: Epoxy resin
Variants: 1, 2, 3 or 4 cores; primarily switchable or non-switchable; secondarily switchable or non-switchable.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core.
Current transformers with one core
STEM-N 1211, STEM-N 2411, STEM-N 3811
Mounting: Indoor | Voltage: 12, 24, 38 kV | Single core
We manufacture these transformers as standard for a thermal current of 100In, but we can also make them for higher thermal currents, depending on the transformation ratio, accuracy class and core burden.
| TECHNICAL DATA | STEM-N 1211 (STEM-N 1210) | STEM-N 2411 (STEM-N 2410) | STEM-N 3811 (STEM-N 3810) |
|---|---|---|---|
| Rated primary voltage (kV) | 10 | 20 | 35 |
| Highest voltage for equipment (eff.) (kV) | 12 | 24 | 38 |
| Rated power-frequency withstand voltage, 1 min. (kV) | 28 | 50 | 70 |
| Rated impulse withstand voltage 1.2/50 µs (kV) | 75 | 125 | 170 |
| Rated frequency (Hz) | 50/60 | ||
| Rated primary current (A) | 5 to 600 or 2x5 to 2x600 | ||
| Rated secondary current (A) | 5 (or 1) | ||
| Rated accuracy class | 0,2; 0,5; 0,2S; 0,5S; 1; 3; 5P; 10P | ||
| Rated thermal current 1 sec. | Ith = (100-500) In | ||
| Rated dynamic current | Idyn = 2,5 Ith | ||
| Rated continuous thermal current | Icth = 1,2 In | ||
| Number of cores | 1 | ||
| Rated core power (VA) | 5; 7,5; 10; 15; 30 | ||
| Security factor / Accuracy limit factor | 5; 10 / 5; 10; 15; 20; 30 | ||
| Temperature class of insulation | E/B | ||
| Possibility of sealing | On primary and secondary side | ||
| Type of basic insulation | Epoxy resin | ||
| Valid standards | IEC 61869-1; IEC 61869-2 | ||
Dimensions (mm)
| Type of transformer | A | B | C | D | E | F | G | H | I | J | Mass (kg) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| STEM-N 1211 | 216 | 158 | 162 | 134 | 27 | 72 | 63 | 220 | 66 | 15 | ~11 |
| STEM-N 2411 | 200 | 180 | 176 | 156 | 30 | 63 | 53 | 270 | 69 | 15 | ~15 |
| STEM-N 3811 | 215 | 184 | 198 | 160 | 45 | 54 | 62 | 390 | 82 | 17 | ~18 |
STEM-N 1211, STEM-N 2411, STEM-N 3811 – transformer with one core, primarily switchable;
STEM-N 1210, STEM-N 2410, STEM-N 3810 – transformer with one core, primarily non-switchable.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core. We reserve the right to make changes.
Current transformers with multiple cores
STEM-N 12*, STEM-N 24*, STEM-N 38*
Mounting: Indoor | Voltage: 12, 24, 38 kV | 1-4 cores
We manufacture these transformers as standard for a thermal current of 100In with 2 cores (measuring core 15VA cl.0.5FS5, protection core 30VA cl.5P10). We can also make them for higher thermal currents and with 1, 3 or 4 cores, depending on the transformation ratio, accuracy class and core burdens.
Primary terminal: STEM-N 12 kV for 1600A < In ≤ 3000A; STEM-N 24-38 kV for 1500A ≤ In ≤ 3000A.
| TECHNICAL DATA | STEM-N 12* | STEM-N 24* | STEM-N 38* |
|---|---|---|---|
| Rated primary voltage (kV) | 10 | 20 | 35 |
| Highest voltage for equipment (eff.) (kV) | 12 | 24 | 38 |
| Rated power-frequency withstand voltage, 1 min. (kV) | 28 | 50 | 70 |
| Rated impulse withstand voltage 1.2/50 µs (kV) | 75 | 125 | 170 |
| Rated frequency (Hz) | 50/60 | ||
| Rated primary current (A) | 5 to 3000 or 2x5 to 2x600 | ||
| Rated secondary current (A) | 5 (or 1) | ||
| Rated accuracy class | 0,2; 0,5; 0,2S; 0,5S; 1; 3; 5P; 10P | ||
| Rated thermal current 1 sec. | Ith = (100-1000) In | ||
| Rated dynamic current | Idyn = 2,5 Ith | ||
| Rated continuous thermal current | Icth = 1,2 In | ||
| Number of cores | 1-4 | ||
| Rated core power (VA) | 5; 7,5; 10; 15; 30 | ||
| Security factor / Accuracy limit factor | 5; 10 / 5; 10; 15; 20; 30 | ||
| Temperature class of insulation | E/B | ||
| Possibility of sealing | On primary and on secondary side | ||
| Type of basic insulation | Epoxy resin | ||
| Valid standards | IEC 61869-1; IEC 61869-2 | ||
Dimensions (mm)
| Type of transformer | A | B | C | D | E | F | G | H | I | J | Mass (kg) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| STEM-N 12* | 327 | 158 | 270 | 134 | 75 | 16 | 176 | 220 | 119 | 16 | ~23 |
| STEM-N 24* | 339 | 178 | 294 | 154 | 87,5 | 17 | 175 | 265 | 130 | 17 | ~27 |
| STEM-N 38* | 305 | 184 | 300 | 162 | 91 | 21,5 | 133 | 390 | 133 | 17,5 | ~36 |
| STEM-N 38*sa | 305 | 184 | 300 | 162 | 91 | 21,5 | 133 | 360 | 133 | 17,5 | ~33 |
STEM-N 1221 (STEM-N 1231), STEM-N 2421 (STEM-N 2431), STEM-N 3821 (STEM-N 3831) – transformer with two (three) cores, primarily switchable;
STEM-N 1220 (STEM-N 1230), STEM-N 2420 (STEM-N 2430), STEM-N 3820 (STEM-N 3830) – transformer with two (three) cores, primarily non-switchable.
Change of transformation ratio can be done on the primary or the secondary side. If it is on the secondary side, “sp” is added at the end of the designation: STEM-N 1220sp – transformer with two cores, secondarily switchable.
STEM-N 3821sa – a transformer with the same characteristics as STEM-N 3821, only 30 mm lower (its height is 360 mm, while the STEM-N 3821 is 390 mm high); it can be installed in cubicles with reduced space for instrument transformers.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core. We reserve the right to make changes.
Current transformers with multiple cores
STEM-NS 24*(12*), STEM-NS 38*, STEM-NS 38*L
Mounting: Indoor | Voltage: 12, 24, 38 kV | 1-4 cores
We can also make these transformers for higher thermal currents and with more cores, depending on the transformation ratio, accuracy class and core burdens.
| TECHNICAL DATA | STEM-NS 24* (STEM-NS 12*) | STEM-NS 38* (STEM-NS 38*L) |
|---|---|---|
| Rated primary voltage (kV) | 20(10) | 35 |
| Highest voltage for equipment (eff.) (kV) | 24(12) | 38 |
| Rated power-frequency withstand voltage, 1 min. (kV) | 50(28) | 70 |
| Rated impulse withstand voltage 1.2/50 µs (kV) | 125(75) | 170 |
| Rated frequency (Hz) | 50/60 | |
| Rated primary current (A) | 5 to 3000 or 2x5 to 2x1250 | |
| Rated secondary current (A) | 5 (or 1) | |
| Rated accuracy class | 0,2; 0,5; 0,2S; 0,5S; 1; 3; 5P; 10P | |
| Rated thermal current 1 sec. | Ith = (100-1000) In | |
| Rated dynamic current | Idyn = 2,5 Ith | |
| Rated continuous thermal current | Icth = 1,2 In | |
| Number of cores | 1-4 | |
| Rated core power (VA) | 5; 7,5; 10; 15; 30 | |
| Security factor / Accuracy limit factor | 5; 10 / 5; 10; 15; 20; 30 | |
| Temperature class of insulation | E/B | |
| Possibility of sealing | On primary and secondary side | |
| Type of basic insulation | Epoxy resin | |
| Valid standards | IEC 61869-1; IEC 61869-2 | |
Dimensions (mm)
| Type of transformer | A | B | C | D | E | F | G | H | I | J | Mass (kg) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| STEM-NS 24(12)* | 412 | 196 | 330 | 174 | 125 | 27 | 200 | 285 | 175 | 15 | ~42 |
| STEM-NS 38* | 412 | 196 | 330 | 174 | 125 | 27 | 200 | 390 | 175 | 15 | ~48 |
| STEM-NS 38*L | 385 | 220 | 350 | 190 | 115 | 27 | 160 | 390 | 160 | 15 | ~58 |
STEM-NS 1221 (STEM-NS 1231), STEM-NS 2421 (STEM-NS 2431), STEM-NS 3821 (STEM-NS 3831) – transformer with two (three) cores, primarily switchable;
STEM-NS 1220 (STEM-NS 1230), STEM-NS 2420 (STEM-NS 2430), STEM-NS 3820 (STEM-NS 3830) – transformer with two (three) cores, primarily non-switchable.
Change of transformation ratio can be done on the primary or the secondary side. If it is on the secondary side, “sp” is added at the end of the designation: STEM-NS 3820Lsp – transformer with two cores, secondarily switchable.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core. We reserve the right to make changes.
Current transformers with multiple cores
STEM-N 24*R, STEM-N 38*R
Mounting: Indoor | Voltage: 24, 38 kV | 1-4 cores | With ribs (barriers)
These transformers are adapted for mounting in cubicles with small distances between phases, since they have an increased creepage distance thanks to the epoxy-resin ribs (barriers) cast at the primary terminals.
We manufacture them as standard for a thermal current of 100In with 2 cores (measuring core 15VA cl.0.5FS5, protection core 30VA cl.5P10). We can also make them for higher thermal currents and with 1, 3 or 4 cores, depending on the transformation ratio, accuracy class and core burdens.
Primarily non-switchable for 1600A ≤ In ≤ 2500A (applies to STEM-N 24-38R).
| TECHNICAL DATA | STEM-N 24*R | STEM-N 38*R |
|---|---|---|
| Rated primary voltage (kV) | 20 | 35 |
| Highest voltage for equipment (eff.) (kV) | 24 | 38 |
| Rated power-frequency withstand voltage, 1 min. (kV) | 50 | 70 |
| Rated impulse withstand voltage 1.2/50 µs (kV) | 125 | 170 |
| Rated frequency (Hz) | 50/60 | |
| Rated primary current (A) | 5 to 3000 or 2x5 to 2x600 | |
| Rated secondary current (A) | 5 (or 1) | |
| Rated accuracy class | 0,2; 0,5; 0,2S; 0,5S; 1; 3; 5P; 10P | |
| Rated thermal current 1 sec. | Ith = (100-1000) In | |
| Rated dynamic current | Idyn = 2,5 Ith | |
| Rated continuous thermal current | Icth = 1,2 In | |
| Number of cores | 1-4 | |
| Rated core power (VA) | 5; 7,5; 10; 15; 30 | |
| Security factor / Accuracy limit factor | 5; 10 / 5; 10; 15; 20; 30 | |
| Temperature class of insulation | E/B | |
| Possibility of sealing | On primary and secondary side | |
| Type of basic insulation | Epoxy resin | |
| Valid standards | IEC 61869-1; IEC 61869-2 | |
Dimensions (mm)
| Type of transformer | A | B | C | D | E | F | G | H | I | J | Mass (kg) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| STEM-N 24*R | 339 | 178 | 286 | 154 | 87 | 17 | 175 | 323 | 130 | 17 | ~29 |
| STEM-N 38*R | 305 | 184 | 292 | 162 | 90,5 | 21,5 | 133 | 448 | 133 | 17,5 | ~37 |
STEM-N 2421R (STEM-N 2431R), STEM-N 3821R (STEM-N 3831R) – transformer with two (three) cores, primarily switchable;
STEM-N 2420R (STEM-N 2430R), STEM-N 3820R (STEM-N 3830R) – transformer with two (three) cores, primarily non-switchable.
Change of transformation ratio can be done on the primary or the secondary side. If it is on the secondary side, “sp” is added at the end of the designation: STEM-N 3820Rsp – transformer with two cores, secondarily switchable.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core. We reserve the right to make changes.
Current transformers with multiple cores
STEM-N 12*d(R), STEM-N 24*d(R)
Mounting: Indoor | Voltage: 12, 24 kV | 1-4 cores | DIN 42600-8
Designed as standard according to DIN 42600-8. On request they can have ribs (barriers).
We manufacture them as standard for a thermal current of 100In with 2 cores (measuring core 15VA cl.0.5FS5, protection core 30VA cl.5P10). We can also make them for higher thermal currents and with 1, 3 or 4 cores, depending on the transformation ratio, accuracy class and core burdens.
| TECHNICAL DATA | STEM-N 12*d(R) | STEM-N 24*d(R) |
|---|---|---|
| Rated primary voltage (kV) | 10 | 20 |
| Highest voltage for equipment (eff.) (kV) | 12 | 24 |
| Rated power-frequency withstand voltage, 1 min. (kV) | 28 | 50 |
| Rated impulse withstand voltage 1.2/50 µs (kV) | 75 | 125 |
| Rated frequency (Hz) | 50/60 | |
| Rated primary current (A) | 5 to 3000 or 2x5 to 2x600 | |
| Rated secondary current (A) | 5 (or 1) | |
| Rated accuracy class | 0,2; 0,5; 0,2S; 0,5S; 1; 3; 5P; 10P | |
| Rated thermal current 1 sec. | Ith = (100-1000) In | |
| Rated dynamic current | Idyn = 2,5 Ith | |
| Rated continuous thermal current | Icth = 1,2 In | |
| Number of cores | 1-4 | |
| Rated core power (VA) | 5; 7,5; 10; 15; 30 | |
| Security factor / Accuracy limit factor | 5; 10 / 5; 10; 15; 20; 30 | |
| Temperature class of insulation | E/B | |
| Possibility of sealing | On primary and secondary side | |
| Type of basic insulation | Epoxy resin | |
| Valid standards | IEC 61869-1; IEC 61869-2; DIN 42600-8 | |
Dimensions (mm)
| Type of transformer | A | B | C | D | E | F | G | H | I | J | K | L | M | Mass (kg) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| STEM-N 12*d(R) | 320 | 148 | 270 | 125 | 96 | 50 | 133 | 220 | 135 | 20 | 86 | 30 | 253 | ~19 |
| STEM-N 24*d(R) | 343 | 178 | 310 | 150 | 101 | 43 | 140 | 280 | 140 | 20 | 90 | 60 | 280 | ~33 |
These 12 kV and 24 kV models are designed according to DIN 42600-8. On request they can have ribs (barriers), which is marked by an additional “R” at the end of the designation.
STEM-N 1221dR – 12 kV transformer with two cores and ribs (barriers), primarily switchable;
STEM-N 2420d – 24 kV transformer with two cores, primarily non-switchable.
Change of transformation ratio can be done on the primary and secondary side; if it is on the secondary side, “sp” is added at the end of the designation: STEM-N 1220dsp – 12 kV transformer with two cores, secondarily switchable.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core. We reserve the right to make changes.
Current transformers with multiple cores – block type
STEM 12*d, STEM 24*d
Mounting: Indoor (block type) | Voltage: 12, 24 kV | 2 (1, 3 or 4) cores | DIN 42600-8
We manufacture them as standard for a thermal current of 100In with 2 cores (measuring core 15VA cl.0.5FS5, protection core 30VA cl.5P10). We can also make them for higher thermal currents and with 1, 3 or 4 cores, depending on the transformation ratio, accuracy class and core burdens.
The primary terminal for In ≥ 2500A is shown in the additional sketch.
| TECHNICAL DATA | STEM 12*d | STEM 24*d |
|---|---|---|
| Rated primary voltage (kV) | 10 | 20 |
| Highest voltage for equipment (eff.) (kV) | 12 | 24 |
| Rated power-frequency withstand voltage, 1 min. (kV) | 28 | 50 |
| Rated impulse withstand voltage 1.2/50 µs (kV) | 75 | 125 |
| Rated frequency (Hz) | 50/60 | |
| Rated primary current (A) | 5 to 3000 or 2x5 to 2x600 | |
| Rated secondary current (A) | 5 (or 1) | |
| Rated accuracy class | 0,2; 0,5; 0,5S; 0,2S; 1; 3; 5P; 10P | |
| Rated thermal current 1 sec. | Ith = (100-1000) In | |
| Rated dynamic current | Idyn = 2,5 Ith | |
| Rated continuous thermal current | Icth = 1,2 In | |
| Number of cores | 2 (1, 3 or 4) | |
| Rated core power (VA) | 5; 7,5; 10; 15; 30 | |
| Security factor / Accuracy limit factor | 5; 10 / 5; 10; 15; 20; 30 | |
| Temperature class of insulation | E/B | |
| Possibility of sealing | On primary and on secondary side | |
| Type of basic insulation | Epoxy resin | |
| Valid standards | IEC 61869-1; IEC 61869-2; DIN 42600 | |
Dimensions (mm)
| Type of transformer | A | B | C | D | E | F | G | H | I | J | K | L | M | Mass (kg) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| STEM 12*d | 363 | 148 | 300 | 125 | 90 | 50,5 | 147,5 | 224 | 155 | 25 | 167 | 150 | 348 | ~23 |
| STEM 24*d | 388 | 178 | 320 | 150 | 105 | 73 | 135 | 283 | 140 | 25 | 177 | 165 | 373 | ~33 |
These 12 kV and 24 kV models are designed according to DIN 42600-8 and are primarily non-switchable.
STEM 1220d – 12 kV transformer with two cores;
STEM 2430d – 24 kV transformer with three cores.
Change of transformation ratio can be done on the secondary side, in which case “sp” is added at the end of the designation: STEM 1220dsp – 12 kV transformer with two cores, secondarily switchable.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core. We reserve the right to make changes.
Current transformers with multiple cores – block type
STEM 12*z, STEM 24*z
Mounting: Indoor (block type) | Voltage: 12, 24 kV | 2 (1, 3 or 4) cores
We manufacture them as standard for a thermal current of 100In with 2 cores (measuring core 15VA cl.0.5FS5, protection core 30VA cl.5P10). We can also make them for higher thermal currents and with 1, 3 or 4 cores, depending on the transformation ratio, accuracy class and core burdens.
| TECHNICAL DATA | STEM 12*z | STEM 24*z |
|---|---|---|
| Rated primary voltage (kV) | 10 | 20 |
| Highest voltage for equipment (eff.) (kV) | 12 | 24 |
| Rated power-frequency withstand voltage, 1 min. (kV) | 28 | 50 |
| Rated impulse withstand voltage 1.2/50 µs (kV) | 75 | 125 |
| Rated frequency (Hz) | 50/60 | |
| Rated primary current (A) | 5 to 3000 or 2x5 to 2x600 | |
| Rated secondary current (A) | 5 (or 1) | |
| Rated accuracy class | 0,2; 0,5; 0,5S; 0,2S; 1; 3; 5P; 10P | |
| Rated thermal current 1 sec. | Ith = (100-1000) In | |
| Rated dynamic current | Idyn = 2,5 Ith | |
| Rated continuous thermal current | Icth = 1,2 In | |
| Number of cores | 2 (1, 3 or 4) | |
| Rated core power (VA) | 5; 7,5; 10; 15; 30 | |
| Security factor / Accuracy limit factor | 5; 10 / 5; 10; 15; 20; 30 | |
| Temperature class of insulation | E/B | |
| Possibility of sealing | On primary and on secondary side | |
| Type of basic insulation | Epoxy resin | |
| Valid standards | IEC 61869-1; IEC 61869-2 | |
Dimensions (mm)
| Type of transformer | A | B | C | D | E | F | G | H | I | J | K | L | Mass (kg) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| STEM 12*z | 333 | 148 | 270 | 125 | 90 | 48 | 135 | 222 | 135 | 15 | 152 | 348 | ~18 |
| STEM 24*z | 353 | 178 | 290 | 150 | 100 | 53 | 140 | 283 | 140 | 20 | 162 | 368 | ~27 |
STEM 1221z (STEM 1231z), STEM 2421z (STEM 2431z) – transformer with two (three) cores, primarily switchable;
STEM 1220z (STEM 1230z), STEM 2420z (STEM 2430z) – transformer with two (three) cores, primarily non-switchable.
Change of transformation ratio can be done on the primary or the secondary side. If it is on the secondary side, “sp” is added at the end of the designation: STEM 1220zsp – transformer with two cores, secondarily switchable.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core. We reserve the right to make changes.
Current transformers with multiple cores – block type
AS 12/150*
Mounting: Indoor (block type) | Voltage: 12 kV | 1 to 6 cores
They can have up to 6 cores.
We manufacture them as standard for a thermal current of 100In. We can also make them for higher thermal currents (up to 500In or more), depending on the transformation ratio, accuracy class and core burdens. On request they can have ribs (barriers).
| TECHNICAL DATA | AS 12/150-b0 | AS 12/150-b1 | AS 12/150-b2 | AS 12/150-b3 | AS 12/150-b4 |
|---|---|---|---|---|---|
| Rated primary voltage (kV) | 10 | ||||
| Highest voltage for equipment (eff.) (kV) | 12 | ||||
| Rated power-frequency withstand voltage, 1 min. (kV) | 28 (42) | ||||
| Rated impulse withstand voltage 1.2/50 µs (kV) | 75 | ||||
| Rated secondary power-frequency withstand voltage 50 Hz, 1 min. (kV) | 3 | ||||
| Rated frequency (Hz) | 50/60 | ||||
| Rated primary current (A) | 5 to 2500 or 2x5 to 2x600 | ||||
| Rated secondary current (A) | 5 (or 1) | ||||
| Rated accuracy class | 0,1; 0,2; 0,5; 0,2S; 0,5S; 1; 3; 5P; 10P | ||||
| Rated thermal current, 1 sec. | Ith = (100-500) In | ||||
| Rated dynamic current | Idyn = 2,5 Ith; max. 120 kA | ||||
| Rated continuous thermal current | Icth = 1,2 In | ||||
| Number of cores | 1 to 6 | ||||
| Rated core power (VA) | 1,25 to 45 | ||||
| Security factor / Accuracy limit factor | 5; 10 / 5; 10; 15; 20; 30 | ||||
| Temperature class of insulation | E | ||||
| Type of basic insulation | Epoxy resin | ||||
| Valid standards | IEC 61869-1; IEC 61869-2 (ГОСТ 7746) | ||||
Dimensions (mm)
| Type of transformer | A | B | C | D | E | F | G | H | I | Mass (kg) |
|---|---|---|---|---|---|---|---|---|---|---|
| AS 12/150-b0 | 191 | 220 | 149 | 133 | 149 | 225 | 170 | 120 | 12 | ~16 |
| AS 12/150-b1 | 219 | 220 | 149 | 152 | 149 | 253 | 198 | 120 | 12 | ~19 |
| AS 12/150-b2 | 299 | 220 | 149 | 183 | 149 | 334 | 280 | 120 | 12 | ~22 |
| AS 12/150-b3 | 299 | 220 | 149 | 183 | 149 | 334 | 280 | 120 | 12 | ~25 |
| AS 12/150-b4 | 419 | 220 | 149 | 302 | 149 | 445 | 400 | 120 | 12 | ~28 |
We make these transformers as standard for a thermal current of 100In, but we can also make them for higher thermal currents (up to 500In or more), depending on the transformation ratio, accuracy class and core burdens.
The transformers can also be made with barriers (ribs) on request.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core. We reserve the right to make changes.
Current transformers with multiple cores – block type
AS 24/180*
Mounting: Indoor (block type) | Voltage: 24 kV | 1 to 6 cores
They can have up to 6 cores.
We manufacture them as standard for a thermal current of 100In. We can also make them for higher thermal currents (up to 500In or more), depending on the transformation ratio, accuracy class and core burdens. On request they can have ribs (barriers).
| TECHNICAL DATA | AS 24/180-b1 | AS 24/180-d1 | AS 24/180-b2 | AS 24/180-b3 | AS 24/180-b4 | AS 24/180-d4 |
|---|---|---|---|---|---|---|
| Rated primary voltage (kV) | 20 | |||||
| Highest voltage for equipment (eff.) (kV) | 24 | |||||
| Rated power-frequency withstand voltage, 1 min. (kV) | 50 (65) | |||||
| Rated impulse withstand voltage 1.2/50 µs (kV) | 125 | |||||
| Rated secondary power-frequency withstand voltage 50 Hz, 1 min. (kV) | 3 | |||||
| Rated frequency (Hz) | 50/60 | |||||
| Rated primary current (A) | 5 to 2000 or 2x5 to 2x600 | |||||
| Rated secondary current (A) | 5 (or 1) | |||||
| Rated accuracy class | 0,1; 0,2; 0,5; 0,2S; 0,5S; 1; 3; 5P; 10P | |||||
| Rated thermal current, 1 sec. | Ith = (100-500) In | |||||
| Rated dynamic current | Idyn = 2,5 Ith; max. 120 kA | |||||
| Rated continuous thermal current | Icth = 1,2 In | |||||
| Number of cores | 1 to 6 | |||||
| Rated core power (VA) | 1,25 to 45 | |||||
| Security factor / Accuracy limit factor | 5; 10 / 5; 10; 15; 20; 30 | |||||
| Temperature class of insulation | E | |||||
| Type of basic insulation | Epoxy resin | |||||
| Valid standards | IEC 61869-1; IEC 61869-2 (ГОСТ 7746) | |||||
Dimensions (mm)
| Type of transformer | A | B | C | D | E | F | G | H | I | Mass (kg) |
|---|---|---|---|---|---|---|---|---|---|---|
| AS 24/180-b1 | 191 | 280 | 149 | 133 | 179 | 225 | 160 | 150 | 14 | ~18 |
| AS 24/180-d1 | 191 | 280 | 179 | 133 | 179 | 225 | 160 | 150 | 14 | ~22 |
| AS 24/180-b2 | 219 | 280 | 149 | 152 | 179 | 253 | 185 | 150 | 14 | ~26 |
| AS 24/180-b3 | 299 | 280 | 149 | 183 | 179 | 334 | 265 | 150 | 14 | ~30 |
| AS 24/180-b4 | 316 | 280 | 149 | 195 | 179 | 350 | 280 | 150 | 14 | ~34 |
| AS 24/180-d4 | 316 | 280 | 179 | 195 | 179 | 350 | 280 | 150 | 14 | ~38 |
We make these transformers as standard for a thermal current of 100In, but we can also make them for higher thermal currents (up to 500In or more), depending on the transformation ratio, accuracy class and core burdens.
The transformers can also be made with barriers (ribs) on request.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core. We reserve the right to make changes.
Current transformers with multiple cores – block type
AN 36/250*
Mounting: Indoor (block type) | Voltage: 35 kV (36/42 kV) | 1 to 6 cores
They can have up to 6 cores.
We manufacture them as standard for a thermal current of 100In. We can also make them for higher thermal currents (up to 500In or more), depending on the transformation ratio, accuracy class and core burdens. On request they can have ribs (barriers).
| TECHNICAL DATA | AN 36/250-d1 | AN 36/250-d2 | AN 36/250-f2 |
|---|---|---|---|
| Rated primary voltage (kV) | 35 | ||
| Highest voltage for equipment (eff.) (kV) | 36 (42) | ||
| Rated power-frequency withstand voltage, 1 min. (kV) | 70 (95) | ||
| Rated impulse withstand voltage 1.2/50 µs (kV) | 170 (190) | ||
| Rated secondary power-frequency withstand voltage 50 Hz, 1 min. (kV) | 3 | ||
| Rated frequency (Hz) | 50/60 | ||
| Rated primary current (A) | 5 to 1250 or 2x5 to 2x600 | ||
| Rated secondary current (A) | 5 (or 1) | ||
| Rated accuracy class | 0,1; 0,2; 0,5; 0,2S; 0,5S; 1; 3; 5P; 10P | ||
| Rated thermal current, 1 sec. | Ith = (100-500) In | ||
| Rated dynamic current | Idyn = 2,5 Ith; max. 120 kA | ||
| Rated continuous thermal current | Icth = 1,2 In | ||
| Number of cores | 1 to 6 | ||
| Rated core power (VA) | 1,25 to 45 | ||
| Security factor / Accuracy limit factor | 5; 10 / 5; 10; 15; 20; 30 | ||
| Temperature class of insulation | E | ||
| Type of basic insulation | Epoxy resin | ||
| Valid standards | IEC 61869-1; IEC 61869-2 (ГОСТ 7746) | ||
Dimensions (mm)
| Type of transformer | A | B | C | D | E | F | G | H | I | Mass (kg) |
|---|---|---|---|---|---|---|---|---|---|---|
| AN 36/250-d1 | 191 | 390 | 179 | 133 | 249 | 225 | 140 | 225 | 14 | ~32 |
| AN 36/250-d2 | 349 | 390 | 179 | 215 | 249 | 385 | 300 | 225 | 14 | ~38 |
| AN 36/250-f2 | 349 | 390 | 224 | 215 | 249 | 385 | 300 | 225 | 14 | ~44 |
We make these transformers as standard for a thermal current of 100In, but we can also make them for higher thermal currents (up to 500In or more), depending on the transformation ratio, accuracy class and core burdens.
The transformers can also be made with barriers (ribs) on request.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core. We reserve the right to make changes.
Current transformers with one core
ATMS 2411(1211), ATMS 3811
Mounting: Outdoor | Voltage: 12, 24, 38 kV | Single core
We manufacture them as standard for a thermal current of 100In with a measuring core 10VA cl.0.5.
We also install them in revenue metering units on pole-mounted substations at the 10 kV and 20 kV voltage level.
| TECHNICAL DATA | ATMS-1211 (ATMS-1210) ATMS-2411 (ATMS-2410) | ATMS-3811 (ATMS-3810) |
|---|---|---|
| Rated primary voltage (kV) | 20(10) | 35 |
| Highest voltage for equipment (eff.) (kV) | 24(12) | 38 |
| Rated power-frequency withstand voltage, 1 min. (kV) | 50(28) | 70 |
| Rated impulse withstand voltage 1.2/50 µs (kV) | 125(75) | 170 |
| Creeping distance (mm) | 570 | 860 |
| Type of mounting | Outdoor | |
| Rated frequency (Hz) | 50/60 | |
| Rated primary current (A) | 5 to 500 or 2x5 to 2x75 | |
| Rated secondary current (A) | 5 (or 1) | |
| Rated accuracy class | 0,5 | |
| Rated thermal current 1 sec. | Ith = (100-500) In | |
| Rated dynamic current | Idyn = 2,5 Ith | |
| Rated continuous thermal current | Icth = 1,2 In | |
| Number of cores | 1 | |
| Rated core power (VA) | 5; 7,5; 10 | |
| Security factor / Accuracy limit factor | 5; 10/5; 10; 15; 20; 30 | |
| Temperature class of insulation | E/B | |
| Type of basic insulation | Cycloaliphatic resin | |
| Valid standards | IEC 61869-1; IEC 61869-2 | |
Dimensions (mm)
| Type of transformer | H | Number of ribs | Mass (kg) |
|---|---|---|---|
| ATMS-2411(1211) | 306 | 6 | ~15 |
| ATMS-3811 | 405 | 9 | ~19 |
ATMS-1211, ATMS-2411, ATMS-3811 – transformer with one core, primarily switchable;
ATMS-1210, ATMS-2410, ATMS-3810 – transformer with one core, primarily non-switchable.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core. We reserve the right to make changes.
Current transformers with one core
ATM 2411(1211), ATM 2411h, ATM 3811
Mounting: Outdoor | Voltage: 12, 24, 38 kV | Single core
We manufacture them as standard for a thermal current of 100In. We can also make them for higher thermal currents depending on the transformation ratio, accuracy class and core burden.
Sealing is done on the secondary side. Model ATM 2411h is intended for more demanding conditions and has a creepage distance of ≥31 mm/kV.
| TECHNICAL DATA | ATM-2411 (ATM-1211) ATM-2410 (ATM-1210) | ATM-2411h (ATM-2410h) | ATM-3811 (ATM-3810) |
|---|---|---|---|
| Rated primary voltage (kV) | 20(10) | 20 | 35 |
| Highest voltage for equipment (eff.) (kV) | 24(12) | 24 | 38 |
| Rated power-frequency withstand voltage, 1 min. (kV) | 50(28) | 50 | 70 |
| Rated impulse withstand voltage 1.2/50 µs (kV) | 125(75) | 125 | 170 |
| Creeping distance (mm) | 490 | 750 | 840 |
| Type of mounting | Outdoor | ||
| Rated frequency (Hz) | 50/60 | ||
| Rated primary current (A) | 5 to 1200 or 2x5 to 2x600 | ||
| Rated secondary current (A) | 5 (or 1) | ||
| Rated accuracy class | 0,2; 0,5; 0,2S; 0,5S; 1; 3; 5P; 10P | ||
| Rated thermal current 1 sec. | Ith = (100-500) In | ||
| Rated dynamic current | Idyn = 2,5 Ith | ||
| Rated continuous thermal current | Icth = 1,2 In | ||
| Number of cores | 1 | ||
| Rated core power (VA) | 5; 7,5; 10; 15; 30 | ||
| Security factor / Accuracy limit factor | 5; 10/5; 10; 15; 20; 30 | ||
| Temperature class of insulation | E/B | ||
| Type of basic insulation | Cycloaliphatic resin | ||
| Valid standards | IEC 61869-1; IEC 61869-2 | ||
Dimensions (mm)
| Type of transformer | H | Number of ribs | Mass (kg) |
|---|---|---|---|
| ATM-2411 (ATM-1211) | 254 | 5 | ~23 |
| ATM-2411h | 372 | 7 | ~29 |
| ATM-3811 | 376 | 8 | ~29 |
ATM-2411 (ATM-1211), ATM-3811 – transformer with one core, primarily switchable;
ATM-2410 (ATM-1210), ATM-3810 – transformer with one core, primarily non-switchable;
ATM-2410(1210)sp, ATM-3810sp – transformer with one core, secondarily switchable.
Switching to another current transformation ratio can be done on the primary or secondary side, with sealing of the terminal cover on the secondary side.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core. We reserve the right to make changes.
Current transformers with one or multiple cores
ATM 24*(12*), ATM 38*, ATM 38*h
Mounting: Outdoor | Voltage: 12, 24, 38 kV (38*h: 40.5 kV) | 1-4 cores
We manufacture them as standard for a thermal current of 100In. We can also make them for higher thermal currents depending on the transformation ratio, accuracy class and core burden.
Sealing is done on the secondary side. Model ATM 3821h is intended for more demanding conditions and BIL (40.5/95/200 kV), and has a creepage distance of ≥31 mm/kV.
The primary terminal for 1500A ≤ In ≤ 3000A is shown in the additional sketch.
| TECHNICAL DATA | ATM-24*(12*) | ATM-38* | ATM-38*h |
|---|---|---|---|
| Rated primary voltage (kV) | 20(10) | 35 | 35 |
| Highest voltage for equipment (eff.) (kV) | 24(12) | 38 | 38 (40,5) |
| Rated power-frequency withstand voltage, 1 min. (kV) | 50(28) | 70 | 70 (95) |
| Rated impulse withstand voltage 1.2/50 µs (kV) | 125(75) | 170 | 170 (200) |
| Creeping distance (mm) | 490 | 840 | 1296 |
| Type of mounting | Outdoor | ||
| Rated frequency (Hz) | 50/60 | ||
| Rated primary current (A) | 5 to 2500 or 2x5 to 2x600 | ||
| Rated secondary current (A) | 5 (or 1) | ||
| Rated accuracy class | 0,2; 0,5; 0,2S; 0,5S; 1; 3; 5P; 10P | ||
| Rated thermal current 1 sec. | Ith = (100-1000) In | ||
| Rated dynamic current | Idyn = 2,5 Ith | ||
| Rated continuous thermal current | Icth = 1,2 In | ||
| Number of cores | 1-4 | ||
| Rated core power (VA) | 5; 7,5; 10; 15; 30 | ||
| Security factor / Accuracy limit factor | 5; 10/5; 10; 15; 20; 30 | ||
| Temperature class of insulation | E/B | ||
| Type of basic insulation | Cycloaliphatic resin | ||
| Valid standards | IEC 61869-1; IEC 61869-2 | ||
Dimensions (mm)
| Type of transformer | H | Number of ribs | Mass (kg) |
|---|---|---|---|
| ATM-24*(12*) | 254 | 5 | ~36 |
| ATM-38* | 376 | 8 | ~44 |
| ATM-38*h | 549 | 12 | ~54 |
ATM-1221, ATM-2421, ATM-3821 – transformer with two cores, primarily switchable;
ATM-1220, ATM-2420, ATM-3820 – transformer with two cores, primarily non-switchable.
Switching to another current transformation ratio can be done on the primary or secondary side, with sealing of the terminal cover on the secondary side.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core. We reserve the right to make changes.
Current transformers with one or multiple cores (for railways)
STSM 38*, STSM 38*L, STSM 38*b
Mounting: Outdoor | Voltage: 35 kV (38/40.5 kV) | 1-4 cores | For railways
We manufacture them as standard for a thermal current of 100In. We can also make them for higher thermal currents depending on the transformation ratio, accuracy class and core burden.
Sealing is done on the secondary side. These models are also intended for more demanding conditions and BIL (40.5/95/200 kV), as they have a creepage distance of ≥31 mm/kV.
| TECHNICAL DATA | STSM 38* | STSM 38*L | STSM 38*b |
|---|---|---|---|
| Rated primary voltage (kV) | 35 | ||
| Highest voltage for equipment (eff.) (kV) | 38 (40,5) | ||
| Rated power-frequency withstand voltage, 1 min. (kV) | 70 (95) | ||
| Rated impulse withstand voltage 1.2/50 µs (kV) | 170 (200) | ||
| Creeping distance (mm) | 1327 | 1327 | 1296 |
| Mass (kg) | ~78 | ~126 | ~146 |
| Type of mounting | Outdoor | ||
| Rated frequency (Hz) | 50/60 | ||
| Rated primary current (A) | 5 to 3000* or 2x5 to 2x600 | ||
| Rated secondary current (A) | 5 (or 1) | ||
| Rated accuracy class | 0,2; 0,5; 0,2S; 0,5S; 1; 3; 5P; 10P | ||
| Rated thermal current 1 sec. | Ith = (100-500) In | ||
| Rated dynamic current | Idyn = 2,5 Ith | ||
| Rated continuous thermal current | Icth = 1,2 In | ||
| Number of cores | 1-4 | ||
| Rated core power (VA) | 5; 7,5; 10; 15; 30; 45*; 60* | ||
| Security factor / Accuracy limit factor | 5; 10/5; 10; 15; 20; 30 | ||
| Temperature class of insulation | E/B | ||
| Type of basic insulation | Cycloaliphatic resin | ||
| Valid standards | IEC 61869-1; IEC 61869-2 | ||
Example designation:
STSM 3821L – transformer with two cores, primarily switchable;
STSM 3820 – transformer with two cores, primarily non-switchable;
STSM 3830b – transformer with three cores, primarily non-switchable.
We make these transformers as standard for a thermal current of 100In, but we can also make them for higher thermal currents depending on the transformation ratio, accuracy class and core burdens.
Switching to another current transformation ratio can be done on the primary or secondary side, with sealing of the terminal cover on the secondary side.
These models can also be made for more demanding conditions – BIL (40.5/95/200 kV), since they also have a longer creepage distance (≥31 mm/kV).
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core. We reserve the right to make changes.
Current transformers with one or multiple cores, 12-42 kV (for railways)
STSM*
Mounting: Outdoor | Voltage: 12, 24, 36 (42) kV | 1 to 4 cores | For railways
We manufacture them as standard for a thermal current of 100In. We can also make them for higher thermal currents (up to 500In or more) depending on the transformation ratio, accuracy class and core burden.
| TECHNICAL DATA | STSM-12 | STSM-24 | STSM-38 |
|---|---|---|---|
| Rated primary voltage (kV) | 10 | 20 | 35 |
| Highest voltage for equipment (eff.) (kV) | 12 | 24 | 36 (42) |
| Rated power-frequency withstand voltage, 1 min. (kV) | 28 (42) | 50 (65) | 70 (95) |
| Rated impulse withstand voltage 1.2/50 µs (kV) | 75 | 125 | 170 (190) |
| Rated secondary power-frequency withstand voltage 50 Hz, 1 min. (kV) | 3 | ||
| Rated frequency (Hz) | 50/60 | ||
| Rated primary current (A) | 5 to 1200 or 2x5 to 2x600 | ||
| Rated secondary current (A) | 5 (or 1) | ||
| Rated accuracy class | 0.1; 0.2; 0.5; 0.2S; 0.5S; 1; 3; 5P; 10P | ||
| Rated thermal current, 1 sec. | Ith = (100-500) In | ||
| Rated dynamic current | Idyn = 2.5 Ith; max. 120 kA | ||
| Rated continuous thermal current | Icth = 1.2 In | ||
| Number of cores | 1 to 4 | ||
| Security factor / Accuracy limit factor | 5; 10/5; 10; 15; 20; 30 | ||
| Rated core power (VA) | 1.25 to 45 | ||
| Temperature class of insulation | F | ||
| Type of basic insulation | Cycloaliphatic resin | ||
| Valid standards | IEC 61869-1; IEC 61869-2 (ГОСТ 7746) | ||
Dimensions (mm)
| Type of transformer | A | B | C | D | E | F | G | Mass (kg) |
|---|---|---|---|---|---|---|---|---|
| STSM-12 | 315 | 372 | 280 | 276 | 224 | 224 | Ø14 | ~30 |
| STSM-24 | 315 | 452 | 280 | 276 | 224 | 224 | Ø14 | ~48 |
| STSM-38 | 315 | 520 | 280 | 276 | 224 | 224 | Ø14 | ~65 |
We make these transformers as standard for a thermal current of 100In, but we can also make them for higher thermal currents (up to 500In or more), depending on the transformation ratio, accuracy class and core burdens.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core. We reserve the right to make changes.
Current transformers with one or multiple cores (for railways)
STSM-38 III
Mounting: Outdoor | Voltage: 35 kV (36/42 kV) | 1 to 4 cores | For railways
We manufacture them as standard for a thermal current of 100In. We can also make them for higher thermal currents depending on the transformation ratio, accuracy class and core burden.
| TECHNICAL DATA | STSM-38 III |
|---|---|
| Rated primary voltage (kV) | 35 |
| Highest voltage for equipment (eff.) (kV) | 36 (42) |
| Rated power-frequency withstand voltage, 1 min. (kV) | 70 (95) |
| Rated impulse withstand voltage 1.2/50 µs (kV) | 170 (190) |
| Rated secondary power-frequency withstand voltage 50 Hz, 1 min. (kV) | 3 |
| Rated frequency (Hz) | 50/60 |
| Rated primary current (A) | 5 to 1200 or 2x5 to 2x600 |
| Rated secondary current (A) | 5 (or 1) |
| Rated accuracy class | 0,1; 0,2; 0,5; 0,2S; 0,5S; 1; 3; 5P; 10P |
| Rated thermal current, 1 sec. | Ith = (100-500) In |
| Rated dynamic current | Idyn = 2,5 Ith; max. 120 kA |
| Rated continuous thermal current | Icth = 1,2 In |
| Number of cores | 1 to 4 |
| Rated core power (VA) | 1,25 to 45 |
| Security factor / Accuracy limit factor | 5; 10/5; 10; 15; 20; 30 |
| Mass (kg) | ~110 |
| Temperature class of insulation | F |
| Type of basic insulation | Cycloaliphatic resin |
| Valid standards | IEC 61869-1; IEC 61869-2 (ГОСТ 7746) |
We make these transformers as standard for a thermal current of 100In, but we can also make them for higher thermal currents depending on the transformation ratio, accuracy class and core burden.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core. We reserve the right to make changes.
Bushing-type current transformers 12-38 kV
Voltage: 12 kV, 24 kV, 38 kV | Mounting: Indoor | Insulation: Epoxy resin
Variants: 1, 2, 3 or 4 cores; primarily switchable or non-switchable; secondarily switchable or non-switchable.
When ordering, always state the transformation ratio, rated burden, accuracy class and security factor or accuracy limit factor for each core.
