Current transducers with closed feedback loop (C/L)
  • Current transducers with closed feedback loop (C/L)

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Manufacturer: LEM

Current transducers with closed feedback loop (C/L)

Features:
  • Broad frequency band
  • Good total accuracy
  • Fast response time (0.5-2 µs)
  • Small temperature drift
  • Excellent linearity (0.1%)
  • Non-invasive measurement (zero loss)
 
Principle of operation of the current transducer with closed feedback loop

    The magnetic flux generated by the primary current Ip is compensated by the flux derived from the current flowing in the secondary winding. The Hall sensor and associated electronics generate a compensating current corresponding to the instantaneous value of the primary current transmitted to the control systems in the form of a voltage drop across the Rm resistor.
    Based on this principle, constructional families of current transducers are made for measuring currents from 0.25A to 10kA (and even in high-current versions up to 500 kA.)
    The measurement accuracy of the rated current at 25oC reaches a maximum of 0.3% - on average 0.5%.

Application:
  • Industry
  • Drives
  • Switching power supplies
Analog current input.  LA, LAH, LF, LT, LTC Series

  Type Nominal Current IPN –Ask
[A]		 Measure range ±Ip
[A]		 Window dimension [mm] Nominal secondary current IS
[mA]		 Measurement accuracy IPN [%] Bandwidth [kHz] Voltage  [kV] Operation temperature range [°C] Supply voltage Vc
[V]
LEM LA 25-NP/SP14

LA 25 – NP/SP14

 0,25 0,36 - 25 ±0,5 0...150 1,7 -10...70 ±15
LEM LA 25-NP

LA 25 – NP *

 5; 6; 8; 12; 25 7; 9; 12; 18; 36 - 25; 24; 24;
24; 25		 ±0,5 0...150 2.5 0...70 ±15
LEM LAH 25-NP

LAH 25 – NP *

 8; 12; 25 0...18; 27; 55 - 24; 24; 25 ±0,3 0...200 5 -25...85 ±12...15
LEM LA 55-P/SP1

LA 55 – P/SP1

 50 100 12,7 x 7 25 ±0,65 0...200 2,5 -25...85 ±12...15
LEM LAH 50-P

LAH 50 – P

 50 0...110 - 25 ±0,25 0...200 5 -25...85 ±12...15
LEM LA 100-P

LA 100-P

 100 150 12,7 x 7 50 ±0,45 0...200 2 0...70 ±12...15
LEM LAH 50-P

LAH 100–P

 100 0...160 - 50 ±0,25 0...200 5 -25...85 ±12...15
LEM LA 125 P/SP1

LA 125 –P/SP1

 125 200 17 x 11 62,5 ±0,6 0...100 3 -25...85 ±12...15
LEM LAH 125-P

LAH 125 – P

 125 200 - 125 ±0,41 0...100 5 -40...85 ±12...15
LEM LA 200-P

LA 200 – P

 200 300 13 x 11 100 ±0,4 0...100 3 -25...85 ±12...15
LEM LA 205-S

LA 205 – S

 200 300 23 x 18 100 ±0,8 0...100 3,25 -10...85 ±12...15
LEM LA 205-T

LA 205 – T

 200 300 20 x 5 100 ±0,8 0...100 3,25 -10...85 ±12...15
LEM LF 205-S

LF 205 – S

 200 420 15,5 100 ±0,5 0...100 3,5 -40...85 ±12...15
LEM LF 210-S

LF 210 – S

 200 420 Ø15,59 100 0,25 0...100 3,5 -40...85 ±11,4..15,75
LEM LA 255-S

LA 255 – S

 250 500 23 x 18 125 ± 0,8 0...100 3,25 -10...85 ±12...18
LEM LA 305-S/SP4

LA 305 – S/SP4

 300 500 25,5 120 ±0,8 0...100 3,5 -25...85 ±12...15
LEM LA 305-T

LA 305 – T

 300 500 20 x 5 120 ±0,8 0...100 3,5 -10...85 ±12...18
LEM LF 305-S

LF 305 – S

 300 500 Ø 20 150 ±0,4 0...100 3 -10...70 ±12...20
LEM LF 310-S

LF 310-S

 300 500 Ø 20 150 0,25 0..100 3,8 -40...85 ±11,4..21
LEM LA 306-S

LA 306-S

 300 700 13 x 30 150 ±0,7 0...50 5,5 -40...85 ±15
LEM LTC 350-SF

LTC 350–SF

 350 1200 Ø 27,5 175 ±0,5 0...100 12 -40...85 ±15...24
LEM LA 305-S/SP1

LA 305 –S/SP1

 500 800 25,5 250 ±0,8 0...100 3,5 -10...85 ±12...18
LEM LT 505-S

LT 505–S

 500 1200 40,5 100 ±0,6 0...150 6 -10...85 ±15...24
LEM LT 505-T

LT 505–T

 500 1200 40 x 6 100 ±0,6 0...150 6 -10...85 ±15...24
LEM LF 505-S

LF 505–S

 500 800 R 15 100 ±0,6 0...100 3 -40...70 ±15...24
LEM LF 510-S

LF 510-S

 500 800 Ø 30,2 100 0,6 0..100 3,8 -40...70 ±14,25...25,2
LEM LTC 600-SF

LTC 600–SF

 500 1500 Ø 42 100 < ±0,7 0...100 13,4 -40...85 ±15...24
LEM LT 1005-S

LT 1005–S

 1000 2000 40,5 200 ±0,4 0...150 3,5 -10...85 ±15...24
LEM LF 1010-S

LF 1010-S

 1000 1500 Ø 38,5 200 0,4 0..100 3,8 -40...85 ±14,25...25,2
LEM LTC 1000-SF

LTC 1000–SF

 1000 2400 Ø 42 200 < ±0,4 0...100 13,4 -40...85 ±15...24
LEM LF 1005-S

LF 1005–S

 1000 1500 40,5 200 ±0,4 0...150 3 -10...85 ±15...24
LEM LT 2005-S

LT 2005–S

 2000 3 000 60,5 400 ±0,3 0...100 6 0...70 ±15...24
LEM LF 2005-S

LF 2005–S

 2000 3000 60,5 400 ±0,3 0...100 6 -25...70 ±15...24
LEM LT 4000-S

LT 4000–S

 4000 6000 Ø 102 800 ±0,5 0...100 6 -25...70 ±24
LEM LT 10000-S

LT 10000–S

 10000 15000 Ø 200 1000 ±0,3 0...100 10 -25...70 ±48...60

* - CURRENT TRANSDUCER LEM LA25-NP - Measurement ranges

Primary winding quantity Primary current Nominal output current IS[mA] ratio primary resistance [mW] Inductance [mH] Connection
nominal IPN [Ask] maximum IP[A]
1 25 36 25 1/1000 0,3 0,023
2 12 18 24 2/1000 1,1 0,09
3 8 12 24 3/1000 2,5 0,21
4 6 9 24 4/1000 4,4 0,37
5 5 7 25 5/1000 6,3 0,58

Connection of secondary circuits

Dimensions [mm]

Drawing: LA 25-NP/SP14 Drawing: LA 25-NP, 35-NP Drawing: LAH 25-NP
LEM LA 25-NP/SP14 LEM LA 25-NP, 35-NP LEM LAH 25-NP
Drawing: LA 55-P/SP1, LA 100-P Drawing: LAH 50-P, LAH 100-P Drawing: LA 125/200-P, LA 125P/
LA 125/200-P,LA 125P/
LEM LA 55-P/SP, LEM 100-P LEM LAH 50-P, LEM LAH 100-P LEM LA125/500-P, LEM LA 125P
Drawing: LA 205-S, LA 205-S/SP1 Drawing: LA 205-T Drawing: LA 255-S
LEM LA 205-S, LEM LA 205-S/SP LEM LA 205-T LEM LAS 255-S

Dimensions [mm]

Drawing: LA 305-T, LA 305-T/SP1 Drawing: LF 305-S Drawing: LA 305-S, LA 305-S/SP1
LEM LA 305-T LEM LA 305-T/SP1 LEM LA 205-T LEM LA305-S, LEM LA 305-S/SP1
Drawing: LA 505-S, LT 1005-S Drawing: LT 505-T, LT 1005-T Drawing: LF 505-S
LEM LA 505-S, LEM LT 1005-S LEM LT 505-T, LEM LT 1005-T LEM LF 505-S
Drawing: LF 1005-S Drawing: LT 2005-S Drawing: LF 2005-S
LEM LF 1005-S LEM LT 2055-S LEM LF 2005-S

Dimensions [mm]

Drawing: LF 210-S Drawing: LF 310-S
LF 210-S LF 310-S
Drawing: LF 510-S Drawing: LF 1010-S
LF 510-S LF 1010-S
Drawing: LT 4000-S Drawing: LT 10000-S
LEM LT 4000-S LEM LT 10000-S
Drawing: LAH 125-P Drawing: LF 205-S
LEM LAH 125-P LEM LF 205-S
Drawing: LA 305-S/SP4 Drawing: LTC 600-SF, LTC 1000-SF
LEM LA 305-S/SP4 LEM LTC 600-SF, LEM LTC 1000-SF


Drawing LTC 350-SF
LEM LTC 350-SF
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Features:
  • Broad frequency band
  • Good total accuracy
  • Fast response time (0.5-2 µs)
  • Small temperature drift
  • Excellent linearity (0.1%)
  • Non-invasive measurement (zero loss)
 
Principle of operation of the current transducer with closed feedback loop

    The magnetic flux generated by the primary current Ip is compensated by the flux derived from the current flowing in the secondary winding. The Hall sensor and associated electronics generate a compensating current corresponding to the instantaneous value of the primary current transmitted to the control systems in the form of a voltage drop across the Rm resistor.
    Based on this principle, constructional families of current transducers are made for measuring currents from 0.25A to 10kA (and even in high-current versions up to 500 kA.)
    The measurement accuracy of the rated current at 25oC reaches a maximum of 0.3% - on average 0.5%.

Application:
  • Industry
  • Drives
  • Switching power supplies
Analog current input.  LA, LAH, LF, LT, LTC Series

  Type Nominal Current IPN –Ask
[A]		 Measure range ±Ip
[A]		 Window dimension [mm] Nominal secondary current IS
[mA]		 Measurement accuracy IPN [%] Bandwidth [kHz] Voltage  [kV] Operation temperature range [°C] Supply voltage Vc
[V]
LEM LA 25-NP/SP14

LA 25 – NP/SP14

 0,25 0,36 - 25 ±0,5 0...150 1,7 -10...70 ±15
LEM LA 25-NP

LA 25 – NP *

 5; 6; 8; 12; 25 7; 9; 12; 18; 36 - 25; 24; 24;
24; 25		 ±0,5 0...150 2.5 0...70 ±15
LEM LAH 25-NP

LAH 25 – NP *

 8; 12; 25 0...18; 27; 55 - 24; 24; 25 ±0,3 0...200 5 -25...85 ±12...15
LEM LA 55-P/SP1

LA 55 – P/SP1

 50 100 12,7 x 7 25 ±0,65 0...200 2,5 -25...85 ±12...15
LEM LAH 50-P

LAH 50 – P

 50 0...110 - 25 ±0,25 0...200 5 -25...85 ±12...15
LEM LA 100-P

LA 100-P

 100 150 12,7 x 7 50 ±0,45 0...200 2 0...70 ±12...15
LEM LAH 50-P

LAH 100–P

 100 0...160 - 50 ±0,25 0...200 5 -25...85 ±12...15
LEM LA 125 P/SP1

LA 125 –P/SP1

 125 200 17 x 11 62,5 ±0,6 0...100 3 -25...85 ±12...15
LEM LAH 125-P

LAH 125 – P

 125 200 - 125 ±0,41 0...100 5 -40...85 ±12...15
LEM LA 200-P

LA 200 – P

 200 300 13 x 11 100 ±0,4 0...100 3 -25...85 ±12...15
LEM LA 205-S

LA 205 – S

 200 300 23 x 18 100 ±0,8 0...100 3,25 -10...85 ±12...15
LEM LA 205-T

LA 205 – T

 200 300 20 x 5 100 ±0,8 0...100 3,25 -10...85 ±12...15
LEM LF 205-S

LF 205 – S

 200 420 15,5 100 ±0,5 0...100 3,5 -40...85 ±12...15
LEM LF 210-S

LF 210 – S

 200 420 Ø15,59 100 0,25 0...100 3,5 -40...85 ±11,4..15,75
LEM LA 255-S

LA 255 – S

 250 500 23 x 18 125 ± 0,8 0...100 3,25 -10...85 ±12...18
LEM LA 305-S/SP4

LA 305 – S/SP4

 300 500 25,5 120 ±0,8 0...100 3,5 -25...85 ±12...15
LEM LA 305-T

LA 305 – T

 300 500 20 x 5 120 ±0,8 0...100 3,5 -10...85 ±12...18
LEM LF 305-S

LF 305 – S

 300 500 Ø 20 150 ±0,4 0...100 3 -10...70 ±12...20
LEM LF 310-S

LF 310-S

 300 500 Ø 20 150 0,25 0..100 3,8 -40...85 ±11,4..21
LEM LA 306-S

LA 306-S

 300 700 13 x 30 150 ±0,7 0...50 5,5 -40...85 ±15
LEM LTC 350-SF

LTC 350–SF

 350 1200 Ø 27,5 175 ±0,5 0...100 12 -40...85 ±15...24
LEM LA 305-S/SP1

LA 305 –S/SP1

 500 800 25,5 250 ±0,8 0...100 3,5 -10...85 ±12...18
LEM LT 505-S

LT 505–S

 500 1200 40,5 100 ±0,6 0...150 6 -10...85 ±15...24
LEM LT 505-T

LT 505–T

 500 1200 40 x 6 100 ±0,6 0...150 6 -10...85 ±15...24
LEM LF 505-S

LF 505–S

 500 800 R 15 100 ±0,6 0...100 3 -40...70 ±15...24
LEM LF 510-S

LF 510-S

 500 800 Ø 30,2 100 0,6 0..100 3,8 -40...70 ±14,25...25,2
LEM LTC 600-SF

LTC 600–SF

 500 1500 Ø 42 100 < ±0,7 0...100 13,4 -40...85 ±15...24
LEM LT 1005-S

LT 1005–S

 1000 2000 40,5 200 ±0,4 0...150 3,5 -10...85 ±15...24
LEM LF 1010-S

LF 1010-S

 1000 1500 Ø 38,5 200 0,4 0..100 3,8 -40...85 ±14,25...25,2
LEM LTC 1000-SF

LTC 1000–SF

 1000 2400 Ø 42 200 < ±0,4 0...100 13,4 -40...85 ±15...24
LEM LF 1005-S

LF 1005–S

 1000 1500 40,5 200 ±0,4 0...150 3 -10...85 ±15...24
LEM LT 2005-S

LT 2005–S

 2000 3 000 60,5 400 ±0,3 0...100 6 0...70 ±15...24
LEM LF 2005-S

LF 2005–S

 2000 3000 60,5 400 ±0,3 0...100 6 -25...70 ±15...24
LEM LT 4000-S

LT 4000–S

 4000 6000 Ø 102 800 ±0,5 0...100 6 -25...70 ±24
LEM LT 10000-S

LT 10000–S

 10000 15000 Ø 200 1000 ±0,3 0...100 10 -25...70 ±48...60

* - CURRENT TRANSDUCER LEM LA25-NP - Measurement ranges

Primary winding quantity Primary current Nominal output current IS[mA] ratio primary resistance [mW] Inductance [mH] Connection
nominal IPN [Ask] maximum IP[A]
1 25 36 25 1/1000 0,3 0,023
2 12 18 24 2/1000 1,1 0,09
3 8 12 24 3/1000 2,5 0,21
4 6 9 24 4/1000 4,4 0,37
5 5 7 25 5/1000 6,3 0,58

Connection of secondary circuits

Dimensions [mm]

Drawing: LA 25-NP/SP14 Drawing: LA 25-NP, 35-NP Drawing: LAH 25-NP
LEM LA 25-NP/SP14 LEM LA 25-NP, 35-NP LEM LAH 25-NP
Drawing: LA 55-P/SP1, LA 100-P Drawing: LAH 50-P, LAH 100-P Drawing: LA 125/200-P, LA 125P/
LA 125/200-P,LA 125P/
LEM LA 55-P/SP, LEM 100-P LEM LAH 50-P, LEM LAH 100-P LEM LA125/500-P, LEM LA 125P
Drawing: LA 205-S, LA 205-S/SP1 Drawing: LA 205-T Drawing: LA 255-S
LEM LA 205-S, LEM LA 205-S/SP LEM LA 205-T LEM LAS 255-S

Dimensions [mm]

Drawing: LA 305-T, LA 305-T/SP1 Drawing: LF 305-S Drawing: LA 305-S, LA 305-S/SP1
LEM LA 305-T LEM LA 305-T/SP1 LEM LA 205-T LEM LA305-S, LEM LA 305-S/SP1
Drawing: LA 505-S, LT 1005-S Drawing: LT 505-T, LT 1005-T Drawing: LF 505-S
LEM LA 505-S, LEM LT 1005-S LEM LT 505-T, LEM LT 1005-T LEM LF 505-S
Drawing: LF 1005-S Drawing: LT 2005-S Drawing: LF 2005-S
LEM LF 1005-S LEM LT 2055-S LEM LF 2005-S

Dimensions [mm]

Drawing: LF 210-S Drawing: LF 310-S
LF 210-S LF 310-S
Drawing: LF 510-S Drawing: LF 1010-S
LF 510-S LF 1010-S
Drawing: LT 4000-S Drawing: LT 10000-S
LEM LT 4000-S LEM LT 10000-S
Drawing: LAH 125-P Drawing: LF 205-S
LEM LAH 125-P LEM LF 205-S
Drawing: LA 305-S/SP4 Drawing: LTC 600-SF, LTC 1000-SF
LEM LA 305-S/SP4 LEM LTC 600-SF, LEM LTC 1000-SF


Drawing LTC 350-SF
LEM LTC 350-SF
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