Closed-loop current transformers
Description
Closed-loop current transformers
The WKO current sensors work according to the proven compensation principle and are suitable for measuring direct, alternating and mixed currents. The primary current flow generates a magnetic flux, which is compensated by an internal secondary coil.
The current evaluation is realized with an electronic circuit and a Hall sensor. The secondary compensation current is an exact reflection of the primary current to be measured.
Unique Selling Point
- Measurement of direct, alternating and mixed currents
- Very high precision and short response time
- Broad frequency spectrum and low-temperature drift
- Very good linearity and overcurrent resistance
- No additional losses in the measuring circuit (DC to 150 kHz)
- Current output for lengthy transmission lines
- High-quality UL-listed insulating materials (e.g. UL94-V0)
Advantages (mechanical)
- Robust housing designs (for horizontal/vertical mounting)
- Variable connections, e.g. clamps, plugs, flat-cable plugs or cables
- Wide range of housings with various push-through openings
- Push-through openings
Typical applications
Industry, Renewable energy, Railway engineering, Energy, automation and building technology
| Type | WKO 25 | WKO 50 | WKO 100 | WKO 300 | WKO 500 | WKO 1000 |
| Primary RMS nominal current IPN [A] |
25 | 50 | 100 | 300 | 500 | 1000 |
| Measuring range IP [A] |
0…±35 | 0…±70 | 0…±150 | 0…±500 | 0…±1000 | 0…±1500 |
| Supply UC [V] |
±12 …15 | ±12 …15 | ±12 …15 | ±12 …15 | ±12 …24 | ±12 …24 |
| Measuring accuracy XG@Ipn [-20…70°C] from IPN [%] |
> ±0,9 | > ±1 | > ±1 | > ±1 | > ±1 | > ±1 |
| Translation KN |
1000 | 1000 | 1000 | 2000 | 5000 | 5000 |
| Secondary RMS Nominal current ISN [mA] |
25 | 50 | 100 | 150 | 100 | 200 |
| Secondary winding Resistive sand RS@70°C [Ω] |
16 | 43 | 24 | 30 | 72 | 48 |
| No load current [mA] |
36+IS | 11+IS | 36+IS | 36+IS | 36+IS | 24+IS |
| Type | WKO 25 | WKO 50 | WKO 100 | WKO 300 | WKO 500 | WKO 1000 |
| Linearity error e [%] |
< ±0,1 | < ±0,1 | < ±0,1 | < ±0,1 | < ±0,1 | < ±0,1 |
| Offset error@25°C IO [mA] |
> 0,3 | > 0,3 | > 0,4 | > 0,2 | > 0,2 | > 0,3 |
| Offset Drift -25°C…+70°C IOT [mA] |
> 0,5 | > 0,5 | > 1 | > 0,5 | > 0,5 | > 0,5 |
| Response time tra[μs] |
> 0,5 | > 0,5 | > 0,5 | > 0,5 | > 0,5 | > 0,5 |
| Response time 10%-90% ta [μs] |
> 1 | > 1 | > 1 | > 1 | > 1 | > 1 |
| dl/dt ta [A/μs] |
> 50 | > 50 | > 100 | > 100 | > 100 | > 100 |
| Bandwidth -1 dB [kHz] |
DC…150 | DC…200 | DC…100 | DC…100 | DC…100 | DC…100 |
| Type | WKO 25 | WKO 50 | WKO 100 | WKO 300 | WKO 500 | WKO 1000 |
| Creepage distance dCp [mm] |
4 | 8 | 10 | 10 | 10 | 15 |
| Air section dCi[mm] |
3 | 7 | 9 | 9 | 9 | 12 |
| Creepage Strength [CTI] |
600 | 600 | 600 | 600 | 600 | 600 |
| AC-Insulation test 50/60Hz 1min Ud [kV] |
3,8 | 3,8 | 3,8 | 3,8 | 6 | 6 |
| Pulse voltage test 1,2/50μs Ui[kV] |
6 | 6 | 6 | 6 | 12,5 | 14,5 |
| Mass [kg] [kg] |
0,08 | 0,022 | 0,125 | 0,125 | 0,240 | 0,450 |
| Type | Pin connection/ 4-pin |
h [mm] |
b [mm] |
b1/b2 [mm] |
t [mm] |
DL [mm] |
p/s [mm] |
a/a1 [mm] |
c1/c2 [mm] |
f [mm] |
e [mm] |
l [mm] |
| WKO 25 | A; -U; +U | 39 | 39 | – | 26 | 10 | – | 2 x 10/6,5 | 25/6,5 | M3 | 6,0 x 4,0 | 9 |
| WKO 50 | A; -U; +U | Please find in the drawing | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| WKO 100 | A; -U; +U | 55 | – | 55/68 | 26 | 20,2 | 45/45 | – | 13,0/– | 4,3 | 6,0×4,0 | 12 |
| WKO 300 | A; -U; +U | 55 | – | 55/68 | 26 | 20,2 | 45/45 | – | 13,0/– | 4,3 | 6,0×4,0 | 12 |
| WKO 500 | A; -U; +U | 70 | – | 70/89 | 33 | 31,0 | 57/57 | – | 15,2/– | 4,3 | 6,0×4,3 | 12 |
| WKO 1000 | A; -U; +U | 95 | – | 94/110 | 44 | 40,0 | 78/78 | – | 18,0/– | 5,3 | 8,0×5,3 | 12 |
All data and configurations can be found in our product data sheet.
