LEM HO15-NSM-SP3103 Current transducer Datasheet

Current Transducer HO-NSM-0000 SERIES IPN = 8, 15, 25 A
Ref: HO 8-NSM-0000, HO 15-NSM-0000, HO 25-NSM-0000
For the electronic measurement of current: DC, AC, pulsed..., with galvanic separation
between the primary and the secondary circuit.
Features
Applications
●● Hall effect measuring principle
●● AC variable speed drives
●● Multirange current transducer through PCB
●● Static converters for DC motor drives
●● Battery supplied applications
pattern lay-out
●● Galvanic separation between primary and secondary circuit
●● Uninterruptible Power Supplies (UPS)
●● Insulated test voltage 4300 V
●● Switched Mode Power Supplies (SMPS)
●● Low power consumption
●● Power supplies for welding applications
●● Extremely low profile 12 mm
●● The solar inverter on DC side of the inverter (MPPT)
●● Single power supply + 5 V
●● Combiner box.
●● Fixed offset & sensitivity
●● Over-current detect 2.63 x IPN (peak value)
●● Memory check.
Standards
●● EN 50178: 1997
●● Small size and space saving
●● IEC 61010-1: 2010
●● IEC 61326-1: 2012
●● UL 508: 2010.
●● Only one design for wide primary current range
Application Domain
Advantages
●● High immunity to external interference
●● 8 mm creepage /clearance
●● Industrial.
●● High insulation capability
●● Fast response.
N°64.52.11.000.0, N°64.52.15.000.0, N°64.52.19.000.0
18February2014/Version 3
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
Page 1/16
www.lem.com
HO-NSM-0000 SERIES
Absolute maximum ratings
Symbol
Unit
Value
Supply voltage (not operating)
Parameter
UC
V
6.5
Primary conductor temperature
TB
°C
120
UESD
kV
2
ESD rating, Human Body Model (HBM)
Stresses above these ratings may cause permanent damage. Exposure to absolute maximum ratings for extended periods may
degrade reliability.
UL 508: Ratings and assumptions of certification
File # E189713 Volume: 2 Section: 5
Standards
●● CSA C22.2 NO. 14-10 INDUSTRIAL CONTROL EQUIPMENT - Edition 11 - Revision Date 2011/08/01
●● UL 508 STANDARD FOR INDUSTRIAL CONTROL EQUIPMENT - Edition 17 - Revision Date 2010/04/15
Ratings
Parameter
Symbol
Primary involved potential
Unit
Value
V AC/DC
600
Max surrounding air temperature
TA
°C
105
Primary current
IP
A
According to series primary
currents
Secondary supply voltage
UC
V DC
5
Output voltage
Vout
V
0 to 5
Conditions of acceptability
When installed in the end-use equipment, consideration shall be given to the following:
1 - These devices have been evaluated for overvoltage category III and for use in pollution degree 2 environment.
2 - A suitable enclosure shall be provided in the end-use application.
3 - The terminals have not been evaluated for field wiring.
4 - These devices have been evaluated for use in 105°C maximum surrounding air temperature.
5 - The secondary (Sensing) circuit is intended to be supplied by a Isolated Secondary Circuit - Limited voltage circuit defined
by UL 508 paragraph 32.5. The maximum open circuit voltage potential available to the circuit and overcurrent protection
shall be evaluated in the end use application.
6 - These devices are intended to be mounted on a printed wiring board of end-use equipment. The suitability of the connections (including spacings) shall be determined in the end-use application.
7 - Primary terminals shall not be straightened since assembly of housing case depends upon bending of the terminals.
8 - Any surface of polymeric housing have not been evaluated as insulating barrier.
9 - Low voltage circuits are intended to be powered by a circuit derived from an isolating source (such as a transformer, optical
isolator, limiting impedance or electro-mechanical relay) and having no direct connection back to the primary circuit (other
than through the grounding means).
Marking
Only those products bearing the UL or UR Mark should be considered to be Listed or Recognized and covered under UL's
Follow-Up Service. Always look for the Mark on the product.
Page 2/16
18February2014/Version 3
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
HO-NSM-0000 SERIES
Insulation coordination
Parameter
Symbol
Unit
Value
Rms voltage for AC isolation test 50/60Hz/1 min
Ud
kV
4.3
Impulse withstand voltage 1.2/50 µs
ÛW
kV
8
Comment
Partial discharge extinction rms voltage @ 10 pC
Ue
V
1650
Clearance (pri. - sec.)
dCI
mm
8
Shortest distance through air
Creepage distance (pri. - sec.)
dCp
mm
8
Shortest path along device
body
V0 according
to UL 94
Case material
Comparative tracking index
CTI
V
600
Application example
-
-
600 V
CAT III PD2
Reinforced insulation, non
uniform field according to
EN 50178
Application example
-
-
300 V
CAT III PD2
Reinforced insulation, non
uniform field according to
IEC 61010
Application example
-
-
1000 V
CAT III PD2
Simple insulation, non uniform
field according to
EN 50178, IEC 61010
Symbol
Unit
Min
Ambient operating temperature
TA
°C
-40
105
Ambient storage temperature
TS
°C
-40
105
Environmental and mechanical characteristics
Parameter
Surrounding temperature according to UL 508
Mass
Typ
°C
m
g
Max
Comment
105
5
Page 3/16
18February2014/Version 3
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
HO-NSM-0000 SERIES
Electrical data IPN = 8 A
At TA = 25°C, UC = + 5 V, NP = 1 turn, RL = 10 KΩ unless otherwise noted (see Min, Max, typ. definition paragraph in page 12).
Parameter
Symbol
Unit
Min
Typ
Max
Primary nominal rms current
IPN
A
Primary current, measuring range
IPM
A
Number of primary turns
NP
Supply voltage
UC
V
Current consumption
IC
mA
Reference voltage
Vref
V
2.475
External reference voltage
Vref
V
0.5
2.65
Output voltage range @ IPM
Vout - Vref
V
-2
2
Output voltage @ IP = 0 A
Vout
V
Electrical offset voltage
VOE
mV
Temperature coefficient of Vref
Temperature coefficient of VOE
TCVref
8
-20
20
1,2,3
4.5
5
5.5
19
25
2.5
2.525
mV/K
Theoretical sensitivity
Gth
mV/A
Sensitivity error
εG
% of IPN
TCG
ppm/K
Internal reference
Vref + VOE
-7
7
±160
-20 °C .. 85 °C
Internal reference
±190
-40 °C .. 105 °C
Internal reference
ppm/K
TCVOE
Temperature coefficient of G
Comment
±0.088
-20 °C .. 85 °C
±0.095
-40 °C .. 105 °C
800 mV/ IPN @ UC = 5 V
100
±0.5
Factory adjustment
±200
-40 °C .. 85 °C
±220
-40 °C .. 105 °C
Linearity error 0 .. IPN
εL
% of IPN
±0.5
@ UC = 5 V
Linearity error 0 .. IPM
εL
% of IPM
±0.8
@ UC = 5 V
%/%
±0.05
Gain error per UC drift
VOM
mV
±4
Reaction time @ 10 % of IPN
tra
µs
2
di/dt = IPN/µs
Response time @ 90 % of IPN
tr
µs
3.5
di/dt = IPN/µs
Frequency bandwidth (- 3 dB)
BW
kHz
Output rms voltage noise (spectral density)
(DC .. 100 kHz)
eno
µV/√Hz
32.9
@ UC = 5 V
Output voltage noise
(DC .. 20 MHz)
Vno
mVpp
Gain error with respect to UC ± 10 %
Magnetic offset voltage
@ IP = 0 after 2.5 x IPN
Standby pin “0” level
250
80
V
Standby pin “1” level
V
Time to switch from standby to normal mode
µs
Over-current detect
V
0.3
UC -0.3
20
2.6 x IPN
2.9 x IPN
3.2 x IPN
peak value
Accuracy @ IPN
X
% of IPN
±1
Accuracy @ IPN @ TA = + 85°C
X
% of IPN
±2.9
See formula note 1)
Accuracy @ IPN @ TA = + 105°C
X
% of IPN
±3.8
See formula note 1)
Note:
1)
= εG + εL
Accuracy @ IP and XTA = ± [X + (TCG/10000) · (TA - 25) + TCVOE · 100 · (TA -25) / (Gth · IP)].
Page 4/16
18February2014/Version 3
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
HO-NSM-0000 SERIES
Electrical data IPN = 15 A
At TA = 25°C, UC = + 5 V, NP = 1 turn, RL = 10 KΩ unless otherwise noted (see Min, Max, typ. definition paragraph in page 12).
Parameter
Symbol
Unit
Min
Primary nominal rms current
IPN
A
Primary current, measuring range
IPM
A
Number of primary turns
NP
Supply voltage
UC
V
Current consumption
IC
mA
Reference voltage
Vref
V
2.475
External reference voltage
Vref
V
0.5
2.65
Output voltage range @ IPM
Vout - Vref
V
-2
2
Output voltage @ IP = 0 A
Vout
V
Electrical offset voltage
VOE
mV
Typ
Max
15
-37.5
37.5
1,2,3
4.5
5
5.5
19
25
2.5
2.525
Internal reference
Vref + VOE
-5
5
±160
-20 °C .. 85 °C
Internal reference
±190
-40 °C .. 105 °C
Internal reference
Temperature coefficient of Vref
TCVref
ppm/K
Temperature coefficient of VOE
TCVOE
mV/K
Theoretical sensitivity
Gth
mV/A
Sensitivity error
εG
% of IPN
±0.5
TCG
ppm/K
±200
Temperature coefficient of G
Comment
±0.075
800 mV/ IPN, @ UC = 5 V
53.33
Factory adjustment
Linearity error 0 .. IPN
εL
% of IPN
±0.5
@ UC = 5 V
Linearity error 0 .. IPM
εL
% of IPM
±0.8
@ UC = 5 V
%/%
±0.05
Gain error per UC drift
VOM
mV
±5
Reaction time @ 10 % of IPN
tra
µs
2
di/dt = IPN/µs
Response time @ 90 % of IPN
tr
µs
3.5
di/dt = IPN/µs
Frequency bandwidth (- 3 dB)
BW
kHz
Output rms voltage noise (spectral density)
(DC .. 100 MHz)
eno
µV/√Hz
Output voltage noise
(DC .. 20 MHz)
Vno
mVpp
Gain error with respect to UC ± 10 %
Magnetic offset voltage
@ IP = 0 after 2.5 x IPN
Standby pin “0” level
V
Standby pin “1” level
V
Time to switch from standby to normal mode
µs
Over-current detect
V
250
17.5
50
0.3
UC -0.3
20
2.6 x IPN
2.9 x IPN
3.2 x IPN
peak value
Accuracy @ IPN
X
% of IPN
±1
Accuracy @ IPN @ TA = + 85 °C
X
% of IPN
±2.8
See formula note 1)
Accuracy @ IPN @ TA = + 105 °C
X
% of IPN
±3.4
See formula note 1)
Note:
1)
= εG + εL
Accuracy @ IP and XTA = ± [X + (TCG/10000) · (TA - 25) + TCVOE · 100 · (TA -25) / (Gth · IP)].
Page 5/16
18February2014/Version 3
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
HO-NSM-0000 SERIES
Electrical data IPN = 25 A
At TA = 25°C, UC = + 5 V, NP = 1 turn, RL = 10 KΩ unless otherwise noted (see Min, Max, typ. definition paragraph in page 12).
Parameter
Symbol
Unit
Min
Primary nominal rms current
IPN
A
Primary current, measuring range
IPM
A
Number of primary turns
NP
Supply voltage
UC
V
Current consumption
IC
mA
Reference voltage
Vref
V
2.475
External reference voltage
Vref
V
0.5
2.65
Output voltage range @ IPM
Vout - Vref
V
-2
2
Output voltage @ IP = 0 A
Vout
V
Electrical offset voltage
VOE
mV
Typ
Max
25
-62.5
62.5
1,2,3
4.5
5
5.5
19
25
2.5
2.525
-5
5
±160
-20 °C .. 85 °C
Internal reference
±190
-40 °C .. 105 °C
Internal reference
TCVref
ppm/K
Temperature coefficient of VOE
TCVOE
mV/K
Gth
mV/A
εG
% of IPN
±0.5
TCG
ppm/K
±200
Sensitivity error
Temperature coefficient of G
Internal reference
Vref + VOE
Temperature coefficient of Vref
Theoretical sensitivity
Comment
±0.075
800 mV/ IPN @ UC = 5 V
32
Factory adjustment
Linearity error 0 .. IPN
εL
% of IPN
±0.5
@ UC = 5 V
Linearity error 0 .. IPM
εL
% of IPM
±0.8
@ UC = 5 V
%/%
±0.05
Gain error per UC drift
VOM
mV
±6
Gain error with respect to UC ± 10 %
Magnetic offset voltage
@ IP = 0 after 2.5 x IPN
Reaction time @ 10 % of IPN
tra
µs
2
di/dt = IPN/µs
Response time @ 90 % of IPN
tr
µs
3.5
di/dt = IPN/µs
Frequency bandwidth (- 3 dB)
BW
kHz
Output rms voltage noise (spectral density)
(DC .. 100 MHz)
eno
µV/√Hz
Output voltage noise
(DC .. 20 MHz)
Vno
mVpp
Standby pin “0” level
V
Standby pin “1” level
V
Time to switch from standby to normal mode
µs
Over-current detect
V
250
10.5
30
0.3
UC -0.3
20
2.6 x IPN
2.9 x IPN
3.2 x IPN
peak value
Accuracy @ IPN
X
% of IPN
±1
Accuracy @ IPN @ TA = + 85 °C
X
% of IPN
±2.8
See formula note 1)
Accuracy @ IPN @ TA = + 105 °C
X
% of IPN
±3.4
See formula note 1)
Note:
1)
= εG + εL
Accuracy @ IP and X TA = ± [X + (TCG/10000) · (TA - 25) + TCVOE · 100 · (TA -25) / (Gth · IP)].
Page 6/16
18February2014/Version 3
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
HO-NSM-0000 SERIES
Typical performance characteristics IPN = 8 A
Linearity error HO 8-NP
Frequency characteristics
Gain [0 dB at 50 Hz]
Spec
Phase
0.3
6.0
180
0.2
4.0
120
2.0
60
0.0
0
Gain [0 dB at 50 Hz]
Linearity error (%)
0.4
0.1
0
-0.1
-0.2
-0.3
-0.4
-0.5
-10
-8
-6
-4
-2
0
2
4
6
8
10
-2.0
-60
-4.0
-120
-6.0
Primary current (A)
10
100
1000
10000
100000
Phase [deg]
0.5
-180
1000000
Frequency [Hz]
Figure 1: Linearity error
Figure 2: Frequency response
Vout
Ip
Vout
Ip
2 µs/div
Figure 3: Step response
1 µs/div
Figure 4: dv/dt
20 mV/div
Figure 5: Output noise
Page 7/16
18February2014/Version 3
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
HO-NSM-0000 SERIES
Typical performance characteristics IPN = 15 A
Linearity error HO 15-NP
Frequency characteristics
Gain [0 dB at 50 Hz]
0.4
0.2
Gain [0 dB at 50 Hz]
Linearity error (%)
0.3
0.1
0
-0.1
-0.2
-0.3
-0.4
-0.5
-20
-15
-10
-5
0
5
10
15
20
Spec
Phase
6.0
180
4.0
120
2.0
60
0.0
0
-2.0
-60
-4.0
-120
-6.0
10
100
Primary current (A)
1000
10000
100000
Phase [deg]
0.5
-180
1000000
Frequency [Hz]
Figure 6: Linearity error
Figure 7: Frequency response
Vout
Ip
Vout
Ip
1 µs/div
2 µs/div
Figure 8: Step response
Figure 9: dv/dt
20 mV/div
Figure 10: Output noise
Page 8/16
18February2014/Version 3
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
HO-NSM-0000 SERIES
Typical performance characteristics IPN = 25 A
Linearity error HO 25-NP
Frequency characteristics
0.5
Phase
6.0
180
0.2
4.0
120
2.0
60
0.0
0
Gain [0 dB at 50 Hz]
Linearity error (%)
Spec
0.3
0.1
0
-0.1
-0.2
-0.3
-0.4
-0.5
-30
-20
-10
0
10
20
30
Primary current (A)
-2.0
-60
-4.0
-120
-6.0
10
100
1000
10000
100000
Phase [deg]
Gain [0 dB at 50 Hz]
0.4
-180
1000000
Frequency [Hz]
Figure 11: Linearity error
Figure 12: Frequency response
Vout
Ip
Vout
Ip
2 µs/div
Figure 13: Step response
1 µs/div
Figure 14: dv/dt
20 mV/div
Figure 15: Output noise
Page 9/16
18February2014/Version 3
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
HO-NSM-0000 SERIES
Maximum continuous DC primary primary current
50
100
40
75
IP (A)
IP (A)
30
20
50
25
10
15A
15A
15A
8A
0
0
0
25
50
75
TA( ℃)
100
0
125
25
50
75
TA( ℃)
100
125
125
100
IP (A)
75
50
25
25A
0
0
25
50
75
TA( ℃)
100
125
Figure 16: IP vs TA for HO series
Important notice: w
hatever the usage and/or application, the transducer jumper temperature shall not go above the maximum
rating of 120 °C as stated in page 2 of this datasheet.
Page 10/16
18February2014/Version 3
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
HO-NSM-0000 SERIES
Measuring range with external reference voltage
50
40
IP (A)
30
20
Upper limit:
IP = - 10 × Vref + 45 (Vref = 0.5 .. 2.65 V)
Lower limit:
IP = - 10 × Vref + 5 (Vref = 0.5 .. 2.65 V)
Upper limit:
IP = - 18.75 × Vref + 84.38 (Vref = 0.5 .. 2.65 V)
Lower limit:
IP = - 18.75 × Vref + 9.38 (Vref = 0.5 .. 2.65 V)
Upper limit:
TA = 105° C
IP = 80 (Vref = 0.5 ..1.94 V)
IP =31.25 × Vref + 140.63 (Vref = 1.94 .. 2.65 V)
TA = 85° C
IP = 90 (Vref = 0.5 ..1.62 V)
IP =31.25 × Vref + 140.63 (Vref = 1.62 .. 2.65 V)
TA = 60° C
IP = 100 (Vref = 0.5 ..1.3 V)
IP =31.25 × Vref + 140.63 (Vref = 1.3 .. 2.65 V)
TA = 25° C
IP = 110 (Vref = 0.5 ..0.98 V)
IP =31.25 × Vref + 140.63 (Vref = 0.98 .. 2.65 V)
Lower limit:
IP = - 31.25 × Vref + 15.63 (Vref = 0.5 .. 2.5 V)
10
0
-10
-20
HO 8
-30
0.5
1
1.5
2
Vref (V)
2.5
100
80
IP (A)
60
40
20
0
-20
-40
HO 15
-60
0.5
1
1.5
2
Vref (V)
2.5
120
90
IP (A)
60
25℃
60℃
85℃
105℃
30
0
-30
-60
-90
HO 25
0.5
1
1.5
2
Vref (V)
2.5
Example with Vref = 0.5 V:
●● The 8 A version has a measuring range from 0 A to 40 A
●● The 15 A version has a measuring range from 0 A to 75 A
●● The 25 A version has a measuring range from 0 A to 80 A at TA = 105° C
Example with Vref = 1.5 V:
●● The 8 A version has a measuring range from - 10 A to 30 A
●● The 15 A version has a measuring range from - 18.7 A to + 56.3 A
●● The 25 A version has a measuring range from - 31.2 A to + 90 A at TA = 85° C
18February2014/Version 3
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
Page 11/16
www.lem.com
HO-NSM-0000 SERIES
Application information
Total primary resistance
The primary resistance is 0.36 mΩ per conductor at 25 °C.
In the following table, examples of primary resistance according to the number of primary turns.
Number of
primary turns
Primary resistance
current rms
RP [ mΩ ]
1
0.12
Recommended connections
IN
2
12
11
8
13
9
12
10
11
8
13
9
12
10
11
8
9
10
OUT
1.18
IN
8
15
25
4
7.5
12.5
2.67
5
8.33
OUT
0.54
IN
3
13
Primary nominal current
IPN[ A ]
OUT
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.
Remark
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.
Page 12/16
18February2014/Version 3
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
HO-NSM-0000 SERIES
HO name and codification
HO-NSM name and codification
as example
HO 15-NSM/SPXXX-1)2)3)4)
HO 15-NSM-1)2)3)4)
The
1)2)3)4)
indicate the transducer programming.
1) Reference out:
2.5 V
 Code: 0
1.65 V
 Code: 1
1.5 V
 Code: 2
0.5 V
 Code: 3
Only Vref IN
 Code: 4
(Low power mode engaged)
2) Response time:
3.5 s
 Code: 0
2 s
 Code: 1
6 s
 Code: 2
3) Control EEPROM:
YES
 Code: 0
NO
 Code: 1
4) Overcurrent detection:
2.9
 Code: 0
3.6
 Code: 1
4.0
 Code: 2
4.8
 Code: 3
5.2
 Code: 4
5.8
 Code: 5
1.7
 Code: 6
2.3
 Code: 7
0.67
 Code: A
0.94
 Code: B
1.17
 Code: C
1.4
 Code: D
1.6
 Code: E
1.9
 Code: F
2.1
 Code: G
2.3
 Code: H
SET_THRESH = 0
SET_THRESH = 1
HO 15-NSM/SP33-1)2)3)4)  + 3.3 V power supply
HO 15-NSM-1)2)3)4)  + 5 V power supply
Page 13/16
18February2014/Version 3
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
HO-NSM-0000 SERIES
PCB Footprint
Reflow profile
Safety
This transducer must be used in limited-energy secondary circuits according to IEC 61010-1.
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 (e.g. primary bus bar, 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.
Page 14/16
18February2014/Version 3
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
HO-NSM-0000 SERIES
Performance parameters definition
Ampere-turns and amperes
The transducer is sensitive to the primary current linkage ΘP (also
called ampere-turns).
ΘP = NP·IP (At)
Where NP is the number of primary turn (depending on
the connection of the primary jumpers)
Caution: As most applications will use the transducer with only
one single primary turn (NP = 1), much of this datasheet is
written in terms of primary current instead of current linkages.
However, the ampere-turns (At) unit is used to emphasis that
current linkages are intended and applicable.
IP (DC)
IP1
0A
-IP1
t1
t
Ip(3)
t2
Ip(t
3)
Figure 17: C
urrent cycle used to measure magnetic and
electrical offset
(transducer supplied)
Transducer simplified model
Electrical offset
The static model of the transducer at temperature TA is:
Vout = G·ΘP + overall error (mV)
In which error =
εG ·ΘP·G + εL·ΘP·G + TCG (TA-25)·ΘP·G + VOE + TCVOE·(TA-25) (mV)
The electrical offset voltage VOE can either be measured when
the ferro-magnetic parts of the transducer are:
With:
●● or in a known magnetization state, like in the current
ΘP = NP·IP : primary current linkage (At)
ΘP max
:m
ax primary current linkage applied to the
transducer (At)
: output voltage (V)
: ambient operating temperature (°C)
: electrical offset current (V)
: temperature coefficient of VOE (mV/K)
: sensitivity of the transducer (V/At)
: temperature coefficient of G (%/K)
: sensitivity error (%)
: linearity error for ΘP max (%)
Vout
TA
VOE
TCVOE
G
TCG
εG
εL(ΘP max)
This model is valid for primary ampere-turns ΘP between -ΘP max
and +ΘP max only.
Sensitivity and linearity
To measure sensitivity and linearity, the primary current (DC) is
cycled from 0 to IP, then to -IP and back to 0 (equally spaced
IP/10 steps). The sensitivity G is defined as the slope of the linear
regression line for a cycle between ± IPN.
The linearity error εL is the maximum positive or negative
difference between the measured points and the linear regression
line, expressed in % of IPN.
Magnetic offset
The magnetic offset voltage VOM is the consequence of a current
on the primary side (“memory effect” of the transducer’s ferromagnetic parts). It is measured using the following primary
current cycle. VOM depends on the current value IP1 (IP1> IPM).
V =
OM
V (t ) − V (t )
2
out
1
out
2
●● completely demagnetized, which is difficult to realize,
cycle shown in figure 17.
Using the current cycle shown in figure 18, the electrical
V =
OE
V (t ) + V (t )
2
1
out
out
2
offset is:
... (T ) = ... (T ) − ... (25 °C)
Note: the transducer has to be demagnetized prior to
the application of the current cycle (for example with a
demagnetization tunnel).
OE
OT
OE
Overall accuracy
The overall accuracy at 25 °C XG is the error in the
- IPN .. + IPN range, relative to the rated value IPN.
It includes:
●● the electrical offset VOE/ ΘP·G (%)
●● the sensitivity error εG (%)
●● the linearity error εL (to IPN) (%)
Response and reaction times
The response time tr and the reaction time tra are shown in
figure 18.
Both depend on the primary current di/dt. They are measured
at nominal ampere-turns.
I
100 %
90 %
Vout
Ip
tr
10 %
tra
t
Figure 18: Response time tr and reaction time tra
18February2014/Version 3
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
Page 15/16
www.lem.com
HO-NSM-0000 SERIES
Dimensions HO 8-NSM-0000, HO 15-NSM-0000, HO 25-NSM-0000 (mm, general linear tolerance ± 0.5 mm)
Required Connection
OUT
11 12 13
1
2
47nF
5Ω
3
4.7nF
200Ω
4
47nF
5
>10kΩ
6
Vout
Vref (IN/OUT)
OCD
STANDBY
7
10 9 8
+ Uc
0V
N/A (connected to ground)
IN
Page 16/16
18February2014/Version 3
LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice
www.lem.com
Similar pages