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071008/7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice.
Current Transducer LAH 25-NP
For the electronic measurement of currents: DC, AC, pulsed ...,
with a galvanic isolation between the primary circuit
(high power) and the secondary circuit (electronic circuit).
Electrical data
IPN Primary nominal current rms 25 At
IPM Primary current, measuring range 1) 0 .. 55 At
R M Measuring resistance @ 2) TA = 70°C TA = 85°C
RM miniRM maxi RM miniRM maxi
with ± 12 V @ IPN [± At DC ]0284 0280 Ω
@ IPN [At RMS ]3)0182 0178 Ω
with ± 15 V @ IPN [± At DC ]67 398 70 394 Ω
@ IPN [At RMS ] 3) 67 263 70 259 Ω
@ IP < IPN 4)
ISN Secondary nominal current rms 25 mA
K NConversion ratio 1 - 2 - 3 : 1000
VCSupply voltage (± 5 %) ± 12 .. 15 V
ICCurrent consumption 10 (@ ± 15V) + ISmA
Accuracy - Dynamic performance data
XAccuracy 5) @ IPN, TA = 25°C ± 0.3 %
εLLinearity error < 0.2 %
Typ Maxi
IOOffset current @ TA = 25°C ± 0.15 mA
IOM Magnetic offset current @ IP = 0 and specified RM,
after an overload of 5 x IPN ± 0.20 ± 0.25 mA
IOT Temperature variation of IO0°C .. + 70°C ± 0.10 ± 0.60 mA
- 25°C .. + 85°C ± 0.10 ± 0.70 mA
tr a Reaction time @ 10 % of IPN < 200 ns
trResponse time 6) to 90 % of IPN step < 500 ns
di/dt di/dt accurately followed > 200 A/µs
BW Frequency bandwidth (- 1 dB) DC .. 200 kHz
General data
TAAmbient operating temperature - 25 .. + 85 °C
TSAmbient storage temperature - 40 .. + 90 °C
R SSecondary coil resistance @ TA = 70°C 72 Ω
@ TA = 85°C 76 Ω
mMass 20 g
Standards EN 50178: 1997
Notes:1) During 10 s, with RM ≤ 109 Ω (VC = ± 15 V)
2) Calculation of RM mini with the maxi. power of the transistors = 0.307W
@ 70°C and the maxi. power of the transistors = 0.302W @ 85°C
3)50 Hz Sinusoidal
4) The measuring resistance RM mini may be lower
(see "LAH Technical Information" leaflet)
5) Without IO & IOM
6) With a di/dt of 100 A/µs.
Features
•Closed loop (compensated) multi-
range current transducer using the
Hall effect
•Printed circuit board mounting
•Insulated plastic case recognized
according to UL 94-V0.
Advantages
•Excellent accuracy
•Very good linearity
•Low temperature drift
•Optimized response time
•Wide frequency bandwidth
•No insertion losses
•High immunity to external
interference
•Current overload capability.
Applications
•AC variable speed drives 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.
Application domain
•Industrial.
IPN = 8-12-25 A
16038
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071008/7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice.
Current Transducer LAH 25-NP
Isolation characteristics
VdRms voltage for AC isolation test, 50/60 Hz, 1 mn 5kV
VwImpulse withstand voltage 1.2/50 µs 12 kV
VePartial discharge extinction voltage rms @ 10pC >2 kV
Mini
dCp Creepage distance 7) 12 mm
dCl Clearance distance 7) 12 mm
CTI Comparative Tracking Index (Group I)175
Application examples
According to EN 50178 and IEC 61010-1 standards and following conditions:
•Over voltage category OV 3
•Pollution degree PD2
•Non-uniform field
Note:7)On PCB with soldering pattern UTEC93-703.
Safety
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 busbar, power supply).
Ignoring this warning can lead to injury and/or cause serious damage.
This transducer is a built-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.
EN 50178 IEC 61010-1
dCp, dCI, Rated isolation voltage Nominal voltage
Single isolation 1000 V 1000 V
Reinforced isolation 500 V 500 V
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071008/7 LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice.
Dimensions LAH 25-NP (in mm. 1 mm = 0.0394 inch)
Remarks
•IS is positive when IP flows from terminals 1, 2, 3 (IN) to
terminals 6, 5, 4 (OUT).
•The jumper temperature and PCB should not exceed 100°C.
•This is a standard model. For different versions (supply
voltages, turns ratios, unidirectional measurements...),
please contact us.
Mechanical characteristics
•General tolerance ± 0.2 mm
•Fastening & connection of primary 6 pins 1 x 0.8 mm
Recommended PCB hole 1.5 mm
•Fastening & connection of secondary 3 pins 0.7 x 0.6 mm
Recommended PCB hole 1.2 mm
125 55 25 1 : 1000 0.18 0.012
212 27 24 2 : 1000 0.81 0.054
3 8 18 24 3 : 1000 1.62 0.110
Number
of primary
turns
Primary current
nominal maximum
IPN [ A ] IP [ A ]
Nominal
output current
ISN [ mA ]
Turns
ratio
K N
Primary
resistance
R P [ mΩ ]
Primary insertion
inductance
L P [ µH ]
Recommended
PCB connections
321IN
OUT 456
3 2 1 IN
OUT 4 5 6
321IN
OUT 456
Connection
Front view
Bottom view
Left view
