Page 104 - Current & voltage sensors catalog

Calculation guide
Closed loop Hall effect current sensors

ES, CS, MP and EL sensors

2.2 - What are the consequences, if the required signal is only 5 V?
R M = V M / I S = 5 / 0.26 = 19.23 Ω
We must check that the sensor can measure these 520 A peak.
1SBC146057V0014 V A > e + V S + V M
If V A = ±15 V (±5%), then we must check that
15 x 0.95 > 1 + (33 x 0.26) + 5 which is false since 14.25 V< 14.58 V
Therefore a supply greater than or equal to 14.58 V must be selected. Select a ±24 V (±5%) supply or a
±15 V supply with a tighter tolerance, for example ±15 V (±2%).
ES300C (since 15 V x 0.98 > 14.58 V)
Conclusion
4
An ES300C sensor can measure a peak of 520 A in the following conditions:
V A = ±15 V (±2%)
R M = 19.23 Ω
to obtain a 5 V signal at a peak of 520 A.
In general, the larger the measuring signal required, the larger the load resistance and the higher the
sensor supply voltage should be. The thermal aspect of the sensor should be considered.
2.3 - What is the maximum current measurable by an ES300C in specific conditions?
For example, the conditions are:
V A = ±15 V (±5%)
R M = 15 Ω
From the base formulas, we obtain the following formula:
I SMAX = (V AMIN - e) / (R S + R M) = [(15 x 0.95) – 1] / (33 + 15) = 0.276 A peak
Now calculate the equivalent primary current:
I P = (N S / N P) x I S = (2000 / 1) x 0.276 = 552 A peak
Conclusion
An ES300C sensor can measure a peak of 552 A in the following conditions:
V A = ±15 V (±5%)
R M = 15 Ω
Note: the 552 A peak current must not be a continuous current. For specific requirements, contact your
distributor.
2.4 - What influence does the ambient temperature have on the sensor's performance?
Taking the conditions from point 2.3 (preceding example). The calculations were made using a maximum
default operating temperature of +70 °C. If this maximum temperature is +50 °C, then the measuring
range can be increased as follows:
R S = 33 Ω at +70 °C At +50 °C, R S = 30.5 Ω then,
I SMAX = (V AMIN - e) / (R S + R M) = [(15 x 0.95) – 1] / (30.5 + 15) = 0.291 A peak
Now calculate the equivalent primary current:
I P = (N S / N P) x I S = (2000 / 1) x 0.291 = 582 A peak
Conclusion
An ES300C sensor can measure a peak of 582 A in the following conditions:
V A = ±15 V (±5%)
R M = 15 Ω
Max. operating temperature = +50 °C
Note: the 582 A peak current must not be a continuous current. For specific requirements, contact your
distributor.
In general, the lower the ambient temperature, the more important the sensor measurable current.
The thermal aspect of the sensor should be considered.

1SBC140071S0201

102 | ABB