IPN = 500 A
Current transducer LF 510-S
For the electronic measurement of current: DC, AC, pulsed..., with galvanic separation
between the primary and the secondary circuit.
Features
Standard
●● Bipolar and insulated current measurement up to 0.8 kA
●● EN 50178: 1997.
●● Current output
●● Closed loop (compensated) current transducer
●● Panel mounting.
Application Domain
●● Industrial.
Advantages
●● High accuracy
●● Very low offset drift over temperature.
Applications
●● Windmills inverters
●● Test and measurement
●● Substations
●● AC variable speed and servo motor drives
●● Statics converters for DC motors drives
●● Battery supplied applications
●● Uninterruptible Power Supplies (UPS)
●● Switched Mode Power Supplies (SMPS)
●● Power supplies for welding applications.
N°97.J9.50.000.0
13October2014/Version 0
Page 1/6
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
LF 510-S
Absolute maximum ratings
Parameter
Symbol
Unit
Value
±UC
V
25.2
Primary conductor temperature
TB
°C
100
Maximum steady state input current (-40 .. 85 °C)
IPN
A
500
Symbol
Unit
Value
Rms voltage for AC insulation test, 50 Hz, 1 min
Ud
kV
3.8
Impulse withstand voltage 1.2/50 µs
ÛW
kV
12.5
Insulation resistance
RIS
MΩ
200
-
-
V0 according
to UL 94
Maximum supply voltage (working) (-40 .. 85 °C)
Insulation coordination
Parameter
Case material
Comparative tracking index
measured at 500 V DC
600
CTI
Clearance and creepage
Comment
See dimensions drawing on page 6
Environmental and mechanical characteristics
Parameter
Symbol
Unit
Min
Ambient operating temperature
TA
°C
-40
70
Ambient storage temperature
TS
°C
-45
85
Mass
m
g
Typ
Max
Comment
240
Page 2/6
13October2014/Version 0
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
LF 510-S
Electrical data
At TA = 25°C, ±UC = ±24 V, RM = 1 Ω, unless otherwise noted.
Lines with a * in the conditions column apply over the -40 .. 85 °C ambient temperature range.
Parameter
Max
Conditions
Unit
Primary nominal rms current
IPN
A
Primary current, measuring range
IPM
A
-800
Measuring resistance
RM
Ω
0
Secondary nominal rms current
ISN
A
Output range
IS
A
Number of secondary turns
NS
Supply voltage
±UC
V
Current consumption
IC
mA
52
58
Offset current, referred to primary
IO
A
±1.3
Magnetic offset current, referred to
primary
IOM
A
±0.7
Sensitivity error
εG
%
-0.5
0.5
* -40 .. 85 °C
Linearity error
εL
% of IPN
-0.1
0.1
* -40 .. 85 °C
Overall accuracy at IPN
XG
% of IPN
-0.6
0.6
* -40 .. 85 °C
Output rms current noise referred to
primary
Ino
A
0.12
1 Hz to 200 kHz (see figure 4)
Reaction time @ 10 % of IPN
tra
µs
<0.5
0 to 500 A, 200 A/µs
Step response time to 90 % of IPN
tr
µs
<0.5
0 to 500 A, 200 A/µs
BW
kHz
200
100
-3 dB, small signal bandwidth
+3 dB (see figure 5)
Frequency bandwidth
Min
Typ
Symbol
500
*
800
*
* Max value of RM is given in
figure 1
-0.16
0.1
*
0.16
*
±25.2
*
5000
±14.25
IP = 0, ±UC = ±15 V
IP = 0, ±UC = ±24 V
* -40 .. 85 °C
After IP = ±2 kA
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 a product.
Page 3/6
13October2014/Version 0
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
LF 510-S
140
130
120
110
100
90
80
70
60
50
40
30
20
10
0
22,8 V & 85 °C
17,1 V & 85 °C
500
14,25 V & 85 °C
400
Ip (A)
RM max (Ω)
Typical performance characteristics
200
............ Input 100 A/div
100
Ouput 100 A/div
0
600
640
680
720
760
800
0
840
Ip (A)
Figure 1: Maximum measuring resistance (TA = -40 .. 85 °C)
2
4
6
8
10
12
Time (µs)
14
16
18
20
Figure 2: Typical step response (0 to 500 A, 200 A/µs)
0
I no referred to primary (A rms)
−60
−70
e no (dBVrms/Hz1/2)
300
−80
−90
−100
−110
10
−1
10
−2
10
−3
10
−120
−4
−130
0
10
10
1
10
2
10
3
10
fc (Hz)
4
10
Figure 3: Typical noise voltage density eno
5
10
6
10
0
10
1
10
2
10
3
4
10
10
fc (Hz)
5
10
6
10
Figure 4: T
ypical total output current noise with RM = 1 Ω
(primary referred, rms) with RM = 1 Ω
(fc is upper cut off frequency of bandpass, low
cut off frequency is 1 Hz).
Figure 3 (noise voltage density) shows if there are discrete
frequencies in the output.
To calculate the noise in a frequency band f1 to f2, the
formula is:
I (f1 to f2 ) = I (f2 ) − I (f1 )
2
no
no
2
no
with Ino(f) read from figure 4 (typical, rms value).
Example:
What is the noise from 1 to 106 Hz?
Figure 4 gives Ino(1 Hz) = 0.4 mA and Ino(106 Hz) = 145 mA.
The output current noise (rms) is therefore:
-3 2
-3 2
− 145 mA referred to primary
(145 ⋅ 10 ) − (0.4 ⋅10 ) −
Page 4/6
13October2014/Version 0
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
LF 510-S
Typical performance characteristics continued
5
90
0
Phase (deg)
Gain (dB)
45
-5
-10
-15
0
-45
-20
-25
0.01
0.10
1.00
10.00
100.00
1000.00
-90
0.01
0.10
1.00
10.00
100.00
1000.00
Frequency (kHz)
Frequency (kHz)
Figure5: Typical frequency response, small signal bandwidth
Performance parameters definition
The schematic used to measure all electrical parameters are:
Sensitivity and linearity
To measure sensitivity and linearity, the primary current (DC) is
+UC
+
+HV
VP
M
IS
RM
0V
-HV
-
-UC
Isolation
barrier
Figure 6: Standard characterization schematics for voltage
output transducers (RM = 50 Ω unless otherwise
noted)
Transducer simplified model
The static model of the transducer at temperature TA is:
IS = G·IP + error
In which
error = IOE + IOT (TA) + εG·G·IP + εGT (TA)·G·IP + εL·G·IPM + IOM
IS
: secondary current (A)
G
: sensitivity of the transducer (A/A)
IP
: primary current (A)
IPM
: primary current, measuring range (A)
TA
: ambient operating temperature (°C)
IOE
: electrical offset current (A)
IOM
: magnetic offset current (A)
IOT (TA) : temperature variation of IO at
temperature TA (A)
εG
: sensitivity error at 25 °C
εGT (TA) : thermal drift of sensitivity at
temperature TA
εL
: linearity error
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:
cycled from 0 to IPM, then to - IPM and back to 0 (equally spaced
IPM/10 steps).
The sensitivity G is defined as the slope of the linear
regression line for a cycle between ± IPM.
The linearity error εL is the maximum positive or negative
difference between the measured points and the linear
regression line, expressed in % of the maximum measured value.
Magnetic offset
Due to its working principle, this type of transducer has no
magnetic offset current IOM.
Electrical offset
The electrical offset current IOE is the residual output current when
the input current is zero.
The temperature variation IOT of the electrical offset current
IOE is the variation of the electrical offset from 25 °C to the
considered temperature.
Overall accuracy
The overall accuracy XG is the error at ± IPN, relative to the rated
value IPN.
It includes all errors mentionned above.
Response and reaction times
The response time tr and the reaction time tra are shown in the next
figure.
Both slightly depend on the primary current di/dt. They are
measured at nominal current .
I
100 %
90 %
IS
Ip
tr
10 %
tra
t
Figure 7: response time tr and reaction time tra
13October2014/Version 0
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
Page 5/6
www.lem.com
LF 510-S
Dimensions (in mm)
Connection
IS
IP
RM
Uc
Uc
dCI
dCP
Mechanical characteristics
Safety
●● General tolerance
±0.5 mm
●● Transducer fastening
Vertical position
6 holes ⌀ 4.3 mm
6 M4 steel screws
Recommended fastening torque 2.1 N·m (±10 %)
●● Primary through-hole
⌀ 30 mm
Or30 × 10 mm
●● Transducer fastening
Horizontal position
4 holes ⌀ 4.3 mm
4 M4 steel screws
Recommended fastening torque 2.1 N·m (±10 %)
●● Connection of secondary
MOLEX 3 pins
This transducer must be used in limited-energy secondary
circuits according to IEC 61010-1.
Remarks
●● IS is positive when IP flows in the direction of arrow.
●● The secondary cables also have to be routed together all the
way.
●● Installation of the transducer is to be done without primary
current or secondary voltage present.
●● Maximum temperature of primary conductor: see page 2.
●● 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: Products/Product
Documentation.
13October2014/Version 0
This transducer must be used in electric/electronic
equipment with respect to applicable standards and safety
requirements in accordance with the manufacturer’s
operating instructions.
Caution, risk of electrical shock
When operating the transducer, certain parts of the module
can carry hazardous voltage (eg. primary connection, power
supply).
Ignoring this warning can lead to injury and/or cause serious
damage.
This transducer is a build-in device, whose conducting parts
must be inaccessible after installation.
A protective housing or additional shield could be used.
Main supply must be able to be disconnected.
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
Page 6/6
www.lem.com