Datasheet

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www.lem.com
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
I
PN
Primary nominal current rms 25 At
I
PM
Primary current, measuring range
1)
0 .. 55 At
R
M
Measuring resistance @
2)
T
A
= 70°C T
A
= 85°C
R
M mini
R
M maxi
R
M mini
R
M maxi
with ± 12 V @ I
PN
[± At
DC
] 0 284 0 280 Ω
@ I
PN
[At
RMS
]
3
)
0 182 0 178 Ω
with ± 15 V @ I
PN
[± At
DC
] 67 398 70 394 Ω
@ I
PN
[At
RMS
]
3)
67 263 70 259 Ω
@ I
P
< I
PN
4)
I
SN
Secondary nominal current rms 25 mA
K
N
Conversion ratio 1 - 2 - 3 : 1000
V
C
Supply voltage (± 5 %) ± 12 .. 15 V
I
C
Current consumption 10 (@ ± 15V) + I
S
mA
Accuracy - Dynamic performance data
X Accuracy
5)
@ I
PN,
T
A
= 25°C ± 0.3 %
ε
L
Linearity error < 0.2 %
Typ Maxi
I
O
Offset current @ T
A
= 25°C ± 0.15 mA
I
OM
Magnetic offset current @ I
P
= 0 and specified R
M
,
after an overload of 5 x I
PN
± 0.20 ± 0.25 mA
I
OT
Temperature variation of I
O
0°C .. + 70°C ± 0.10 ± 0.60 mA
- 25°C .. + 85°C ± 0.10 ± 0.70 mA
t
r a
Reaction time @ 10 % of I
PN
< 200 ns
t
r
Response time
6)
to 90 % of I
PN
step < 500 ns
di/dt di/dt accurately followed > 200 A/µs
BW Frequency bandwidth (- 1 dB) DC .. 200 kHz
General data
T
A
Ambient operating temperature - 25 .. + 85 °C
T
S
Ambient storage temperature - 40 .. + 90 °C
R
S
Secondary coil resistance @ T
A
= 70°C 72 Ω
@ T
A
= 85°C 76 Ω
m Mass 20 g
Standards EN 50178: 1997
Notes:
1)
During 10 s, with R
M
≤ 109 Ω (V
C
= ± 15 V)
2)
Calculation of R
M 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 R
M mini
may be lower
(see "LAH Technical Information" leaflet)
5)
Without I
O
& I
OM
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.
I
PN
= 8-12-25 A
16038