CASR-15-NP Datasheet, PDF (5/24 Pages) LEM – CAS / CASR / CKSR series Current Transducers

Multifunctional primary circuit
The CAS and CASR construction uses three U‑shaped primary terminals integrated into the housing, providing the
designer with a great flexibility to perfectly adapt the measuring range of the current transducer to his application.
Fig. 4a shows the different connection possibilities.
Number
of primary
turns
1
Primary nominal
current rms
I_PN [ A ]
± 25
Nominal*
output voltage
V_OUT [ V ]
2.5 ± 0.625
Primary resistance
R_P [ mΩ ] ( typ. )
at +25° C
0.24
Recommended
connections
2
± 12
2.5 ± 0.600
1.08
3
±8
2.5 ± 0.600
2.16
* Output voltage CASR 25‑NP is used with internal reference.
Fig. 4a. Different nominal current ranges possible according to the primary current circuit configuration (as example: CAS or CASR 25-NP)
Variant 1
Variant 2
Expected for:
I_PN (I_PMAX) = 25 A (85 A max)
Expected for:
I_PN/ 3 (I_PMAX/ 3) = 8.33 A (28.33 A max)
Fig. 4b. The 2 extreme possibilities for connecting the primary
current circuit (as example: CAS or CASR 25-NP)
When all three U-shaped terminals are connected in
parallel (variant 1 Fig. 4b) the user can measure the
maximum nominal primary current.
The variant 2 (Fig.4b) corresponds to a series connection
of the primary terminals and leads to a reduction of the
nominal measuring range by a factor of 3, but offering a
3 times higher accuracy for low currents.
Fig. 3. CAS and CASR transducers can be mounted at the
exact place of the LTS and LTSR transducers
The CAS / CASR models are 100% compatible
with the LTS and LTSR models in regards to
the footprint mounting and also with all the
other models that are available on the market
with the same footprint as the LTS / LTSR.