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11July2018/Version 1

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LES series

Overall accuracy

The overall accuracy at 25 °C X

G is the error in the −I

P N … +IP N

range, relative to the rated value I

P N.

It includes:

● the electrical offset V

O E

● the sensitivity error ε

G

● the linearity error ε

L (to IP N)

Response and reaction times

The response time t

r and the reaction time tra are shown in figure

28.

Both depend on the primary current di/dt. They are measured at

nominal ampere-turns.

Figure 28: Response time t

r and reaction time tra

Electrical offset

The electrical offset voltage V

O E can either be measured when

the ferro-magnetic parts of the transducer are:

● Completely demagnetized, which is difficult to realize,

● or in a known magnetization state, like in the current cycle

shown in figure 26.

Using the current cycle shown in figure 26, the electrical offset

is:

The temperature variation V

O T of the electrical offset voltage

V

O E is the variation of the electrical offset from 25 °C to the

considered temperature:

Note: the transducer has to be demagnetized prior to

the application of the current cycle (for example with a

demagnetization tunnel).

Figure 27: Test connection

Performance parameters definition

tra

V

out

t

r

90 %

10 %

t

100 %

I

P

I

2

V

out (t1) + Vout (t2)

V

O E =

V

O T (T) = VO E (T) − VO E (25° C)

2

V

out (t1) + Vout (t2)

V

O E =

V

O T (T) = VO E (T) − VO E (25° C)