LT 4000-S

**Current Transducer LT 4000-S** 

## _I_ **= 4000 A** P N 

For the electronic measurement of current: DC, AC, pulsed..., with galvanic separation between the primary and the secondary circuit. 

## **Features** 

- ●Bipolar and insulated current measurement 

- ●Current output 

- ●Closed loop (compensated) current transducer using the Hall effect 

- ●Panel mounting. 

## **Standards** 

- ●IEC 61010-1: 2016 

- ●EN 61326-1: 2012. 

## **Application Domain** 

- ●Industrial. 

## **Advantages** 

- ●Excellent accuracy 

- ●Very good linearity 

- ●Low temperature drift 

- ●Optimized delay time 

- ●Wide frequency bandwidth 

- ●No insertion losses 

- ●High immunity to external interference 

- ●Current overload capability. 

## **Applications** 

- ●AC variable speed and servo motor drives 

- ●Static converters for DC motor drives 

- ●Battery supplied applications 

- ●Uninterruptible Power Supplies (UPS) 

- ●Switched Mode Power Supplies (SMPS) 

- ●Power supplies for welding applications. 

N° 97.43.74.000.0 

Page 1/8 LEM International SA Route du Nant-d’Avril, 152 1217 Meyrin www.lem.com 

LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 

15August2024/Version 10 

**LT 4000-S** 

## **Safety** 

⚠ Caution 

If the device is used in a way that is not specified by the manufacturer, the protection provided by the device may be compromised. Always inspect the electronics unit and connecting cable before using this product and do not use it if damaged. Mounting assembly shall guarantee the maximum primary conductor temperature, fulfill clearance and creepage distance, minimize electric and magnetic coupling, and unless otherwise specified can be mounted in any orientation. 

Caution, risk of electrical shock 

This transducer must be used in limited-energy secondary circuits SELV according to IEC 61010-1, in electric/electronic equipment with respect to applicable standards and safety requirements in accordance with the manufacturer’s operating specifications. 

Use caution during installation and use of this product; certain parts of the module can carry hazardous voltages and high currents (e.g. power supply, primary conductor). 

Ignoring this warning can lead to injury and and/or cause serious damage. 

De-energize all circuits and hazardous live parts before installing the product. 

All installations, maintenance, servicing operations and use must be carried out by trained and qualified personnel practicing applicable safety precautions. 

This transducer is a build-in device, whose hazardous live parts must be inaccessible after installation. This transducer must be mounted in a suitable end-enclosure. 

Besides make sure to have a distance of minimum 30 mm between the primary terminals of the transducer and other neighboring components. 

Main supply must be able to be disconnected. 

Always inspect the current transducer for damage before using this product. 

Never connect or disconnect the external power supply while the primary circuit is connected to live parts. Never connect the output to any equipment with a common mode voltage to earth greater than 30 V. 

Always wear protective clothing and gloves if hazardous live parts are present in the installation where the measurement is carried out. 

This transducer is a built-in device, not intended to be cleaned with any product. Nevertheless if the user must implement cleaning or washing process, validation of the cleaning program has to be done by himself. 

## ESD susceptibility 

The product is susceptible to be damaged from an ESD event and the personnel should be grounded when handling it. 

Do not dispose of this product as unsorted municipal waste. Contact a qualified recycler for disposal. 

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15August2024/Version 10 

**LT 4000-S** 

## **Absolute maximum ratings** 

|**Parameter**|**Symbol**|**Unit**|**Value**|
|---|---|---|---|
|Maximum supply voltage (working) (−25 … 70 °C)|±_U_C max|V|±25.2|
|Maximum primary conductor temperature|_T_B max|°C|100|



Absolute maximum ratings apply at 25 °C unless otherwise noted. 

Stresses above these ratings may cause permanent damage. Exposure to absolute maximum ratings for extended periods may degrade reliability. 

## **Environmental and mechanical characteristics** 

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**----- Start of picture text -----**<br>
Parameter Symbol Unit Min Typ Max Comment<br>**----- End of picture text -----**<br>


|**Parameter**|**Symbol**|**Unit**|**Min**|**Typ**|**Max**|**Comment**|
|---|---|---|---|---|---|---|
||||||||
|Ambient operating temperature|_T_A|°C|−25||70||
|Ambient storage temperature|_T_A st|°C|−40||85||
|Relative humidity|_RH_|%|20||80|non-condensing|
|Mass|_m_|g||6000|||
|Altitude||m|||2000 1)||



Note:[1)] Insulation coordination at 2000 m. 

## **Insulation coordination** 

|**Parameter**|**Symbol**|**Unit**|_≤_**Value**|**Comment**|
|---|---|---|---|---|
|RMS voltage for AC insulation test, 50 Hz, 1 min|_U_d|kV|6||
|Impulse withstand voltage 1.2/50 μs|_U_Ni|kV|17.7|According to IEC 61010-1|
|Partial discharge RMS test voltage (_q_m< 10 pC)|_U_t|V|5760|Test carried out with a non<br>insulated bar and completely flling<br>the primary hole.<br>According to to IEC 61287-1<br>(not performed on serial test)|
|Clearance (pri. - sec.)|_d_CI|mm|69.8|Shortest distance through air|
|Creepage distance (pri. - sec.)|_d_Cp|mm|75.8|Shortest path along device body|
|Case material|-|-|V0|According to UL 94|
|Comparative tracking index|_CTI_||600|Material group I|
|Application example<br>RMS voltage line-to-neutral||V|> 1500|Basic insulation according to<br>IEC 60664-1 CAT III, PD2|
|Application example<br>RMS voltage line-to-neutral||V|1000|Reinforced insulation according to<br>IEC 60664-1 CAT III, PD2|



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15August2024/Version 10 

**LT 4000-S** 

## **Electrical data** 

At _T_ A = 25 °C unless otherwise noted (see Min, Max, typ, definition paragraph). 

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**----- Start of picture text -----**<br>
Parameter Symbol Unit Min Typ Max Comment<br>**----- End of picture text -----**<br>


|**Parameter**|**Symbol**|**Unit**|**Min**|**Typ**|**Max**|**Comment**|
|---|---|---|---|---|---|---|
||||||||
|Primary nominal DC current (continuous)|_I_P N DC|A|−4000||4000||
|Primary nominal AC RMS current (continuous)|_I_P N AC|A|−4000||4000|_f_≤ 100 Hz|
|Primary current, measuring range|_I_P M|A|−6000||6000|With ±_U_C= ±24 V<br>(−5 %),_T_A= 70 °C,<br>_R_M= 2 Ω; for other<br>conditions, seefgure 1|
|Measuring resistance|_R_M|Ω|0||||
|Secondary nominal RMS current|_I_S N|mA|−800||800||
|Resistance of secondary winding|_R_S|Ω|12.5|12.8|13|@ 25 °C1)|
|Number of secondary turns|_N_S|||5000|||
|DC supply voltage⎓|_U_C|V|±22.8|±24|±25.2||
|DC current consumption⎓|_I_C|mA|25|27 +_I_S×_N_P/_N_S|29|@_U_C= ±24 V @ 25 °C|
|Total error|_ε_tot|%|||±0.5|@ 25 °C (@_I_P N)|
||||||±0.8|@ −25 ... 70 °C (@_I_P N)|
|Electrical ofset current|_I_O E|mA|||±0.8|@ 25 °C (@_I_P= 0)|
|Temperature variation of_I_O E|_I_O_T_|mA||±0.6|±0.8|referred to 25 °C|
|Magnetic ofset current|_I_O M|mA||0.2||after 3 ×_I_P N@ 25 °C|
|Linearity error|_ε_L|% of_I_P N|||< 0.1|@ 25 °C|
||||||< 0.2|@ −25 °C ... 70 °C|
|RMS noise 1 Hz … 10 MHz<br>referred to primary|_I_no|mA||90||seefgure 4|
|Delay time to 10 % of the fnal output value<br>_I_P Nstep|_t_D 10|µs||< 1||With_d_i/_d_t > 50 A/µs<br>Seefgure 2|
|Delay time to 90 % of the fnal output value<br>_I_P Nstep|_t_D 90|µs||< 1||With_d_i/_d_t > 50 A/µs<br>Seefgure 2|
|Frequency bandwidth (−1 dB)|_BW_|kHz||10||With ±_U_C= ±24 V,<br>_T_A= 25 °C, primary<br>return twisted on back<br>side; seefgure 5|
|Frequency bandwidth (−3 dB)||||130|||



Note:[1)] _R_ S ( _T_ A) = _R_ S × (1 + 0.004 × ( _T_ A + _∆_ Temp −25)) estimated temperature increase @ _I_ P N is _∆_ Temp = 15 °C. 

## **Definition of typical, minimum and maximum values** 

Minimum and maximum values for specified limiting and safety conditions have to be understood as such as well as values shown in “typical” graphs. 

On the other hand, measured values are part of a statistical distribution that can be specified by an interval with upper and lower limits and a probability for measured values to lie within this interval. 

Unless otherwise stated (e.g. “100 % tested”), the LEM definition for such intervals designated with “min” and “max” is that the probability for values of samples to lie in this interval is 99.73 %. 

For a normal (Gaussian) distribution, this corresponds to an interval between −3 sigma and +3 sigma. If “typical” values are not obviously mean or average values, those values are defined to delimit intervals with a probability of 68.27 %, corresponding to an interval between −sigma and +sigma for a normal distribution. 

Typical, maximal and minimal values are determined during the initial characterization of the product. 

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15August2024/Version 10 

**LT 4000-S** 

## **Typical performance characteristics** 

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**----- Start of picture text -----**<br>
35<br>±24V(-5%) @ 25°C<br>30 ±24V(-5%) @ 50°C<br>25 ±24V(-5%) @ 70°C<br>20<br>15<br>10<br>5<br>0<br>2500 3500 4500 5500 6500 7500 8500<br>Ip (A)<br>Figure 1: Maximun measuring resistance Figure 2:  ch1:   I P = 4000 A/ch2:  I S = 0.2 A/div,  d i/ d t 50 A/µs<br>R Mmax  =  N S × U C min I − P 0.7 V − R Smax according to the report CA031109 (test done on LT 4000-T/SP42)<br>0 Output voltage noise (spectral density) Cumulated output RMS noise voltage<br>1.E+00<br>-20<br>-40<br>1.E-01<br>-60<br>-80<br>-100 1.E-02<br>-120<br>-140 1.E-03<br>-160 Radia eid Cady cw ERS Ay, Ald<br>-180<br>1.E-04<br>1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07<br>-2001.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 f (Hz)<br>f (Hz)<br>NoiseFloor 2210_24 #02 NoiseFloor 2210_24 #02<br>Figure 3:  Typical output noise voltage spectral density  Figure 4:  Typical output RMS noise current with  R M = 1 Ohm<br>with  R M = 1 Ohm (test done on LT 4000-S/SP35) (primary refered) (test done on LT 4000-S/SP35)<br>) 𝐻𝑧 )RMS<br> (mV<br> (dB V RMS/√ u no U no<br>**----- End of picture text -----**<br>


Figure 5: Frequency bandwidth 

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LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 

15August2024/Version 10 

**LT 4000-S** 

## **Terms and definitions** 

## **Ampere-turns and amperes** 

The transducer is sensitive to the primary current linkage _Θ_ P (also called ampere-turns). 

_Θ_ P = _N_ P∙ _I_ P 

Where _N_ P is the number of primary turn. 

Caution: As most applications will use the transducer with only one single primary turn ( _N_ P = 1), much of this datasheet is written in terms of primary current instead of current linkages. However, the ampere-turns (A) unit is used to emphasis that current linkages are intended and applicable. 

## **Simplified transducer model** 

The static model of the transducer with current output at temperature _T_ A is: 

_I_ S = _Θ_ P ∙ (1 + _ε_ ) 

In which (referred to primary): 

_ε_ ∙ _Θ_ P = _I_ O E + _I_ O _T_ + _ε_ L( _Θ_ P max) ∙ _Θ_ P max + _I_ O M 

- _Θ_ P = _N_ P ∙ _I_ P : primary current linkage (A) 

- _Θ_ P max :  maximum primary current linkage applied to the transducer 

- _I_ S : secondary current (A) _T_ A : ambient operating temperature (°C) _I_ O E : electrical offset current (A) _I_ O M : magnetic offset current (A) 

- _I_ O _T_ : temperature variation of _I_ O E (A) _ε_ L( _Θ_ P max) : linearity error for _Θ_ P max 

This model is valid for primary ampere-turns _Θ_ P between − _Θ_ P max and + _Θ_ P max only. 

This is the absolute maximum error. As all errors are independent, a more realistic way to calculate the error would be to use the following formula: 

## **Total error referred to primary** 

The total error _ε_ tot is the error at ± _I_ P N, relative to the rated value _I_ P N. 

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**----- Start of picture text -----**<br>
N<br>2<br>ε = ∑ε i<br>i =1<br>**----- End of picture text -----**<br>


It includes all errors mentioned above 

- ●the electrical offset _I_ O E 

- ●the magnetic offset _I_ O M 

- ●the linearity error _ε_ L (to _I_ P N). 

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**----- Start of picture text -----**<br>
Total error  ℇ tot<br>0.12 at  U C = ... V and  T A = 25 °C<br>aver. + 3σ<br>0.10<br>0.08<br>0.06 I O M (max) /  I P N<br>=<br>0.04<br>I O E (max) /  I P N<br>0.02<br>0.00<br>-0.02<br>-1 -0.5 0 0.5 1<br>I P / ( K OL ·  I P N) with  K OL = 1 ... 10<br> (% ) I P N<br>tot<br>ℇ<br>**----- End of picture text -----**<br>


Figure 6 **:** Total error _ε_ tot 

## **Electrical offset referred to primary** 

Using the current cycle shown in figure 6 the electrical offset current _I_ O E is the residual output referred to primary when the input current is zero. 

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The temperature variation _I_ O _T_ of the electrical offset current _I_ O E is the variation of the electrical offset from 25 °C to the considered temperature. 

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## **Magnetic offset referred to primary** 

The magnetic offset current on the primary side (“memory effect” of the transducer’s ferro- _I_ O M is the consequence of a current magnetic parts). It is measured using the following primary current cycle. _I_ O M depends on the current value _I_ P _≥ I_ P N. _K_ OL: Overload factor 

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**----- Start of picture text -----**<br>
Primary current cycle<br>1<br>0<br>-1<br>1 2 3 4 5<br>Step<br>)<br>N<br>P<br>I<br> ·<br> = 1 .. 10<br>OL OL<br>K K<br> / (<br>P<br>I with<br>**----- End of picture text -----**<br>


Figure 7:  Current cycle used to measure magnetic and electrical offset (transducer supplied) 

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LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 

15August2024/Version 10 

**LT 4000-S** 

## **Sensitivity and linearity** 

To measure sensitivity and linearity, the primary current (DC) is cycled from 0 to _I_ P, then to − _I_ P and back to 0 (equally spaced _I_ negative difference between the measured points and the P/10 steps). The linearity error _ε_ L is the maximum positive or linear regression line, expressed in % of _I_ P N. 

## **Delay times** 

respect to the primary are shown in the next figure.The delay time _t_ D 10 @ 10 % and the delay time _t_ D 90 @ 90 % with Both slightly depend on the primary current d _i_ /d _t_ . They are measured at nominal current. 

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**----- Start of picture text -----**<br>
I<br>100 %<br>90 %<br>I P IS<br>t D 90<br>10 %<br>t D 10 t<br>**----- End of picture text -----**<br>


Figure 8: _t_ D 10 (delay time @ 10 %) and _t_ D 90 (delay time @ 90 %). 

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LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 

15August2024/Version 10 

**LT 4000-S** 

## **Dimensions** (in mm) 

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**----- Start of picture text -----**<br>
Connection<br>**----- End of picture text -----**<br>


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**----- Start of picture text -----**<br>
I<br>I P S R M<br>+U<br>C<br>-U<br>C<br>**----- End of picture text -----**<br>


## **Mechanical characteristics** 

- ●General tolerance 

- ●Transducer fastening 

±1 mm 

- 4 notches ⌀ 10.5 mm 

4 × M10 steel screws 

Recommended fastening torque 

11.5 N∙m (±10 %) 

- ●Connection of primary 

●Connection of primary ⌀ 102 mm ●Connection of secondary M5 threaded studs Recommended fastening torque 2.2 N∙m (±10 %) 

- ●Connection of secondary 

## **Remarks** 

- _I_ S is positive when _I_ P flows in the direction of arrow. 

- ●The secondary cables also have to be routed together all the way. 

- ●Dynamics performances "delay time" are best with a single bar completely filling the primary hole. 

- ●Installation of the transducer must be done, unless otherwise specified on the datasheet, according to LEM Transducer Generic Mounting Rules. Please refer to LEM document N°ANE120504 available on our Web site: **https://www.lem.com/en/file/3137/download/** 

Page 8/8 LEM International SA Route du Nant-d’Avril, 152 1217 Meyrin www.lem.com 

LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice 

15August2024/Version 10