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28January2014/version 7

LEM reserves the right to carry out modifications on its transducers, in order to improve them, without prior notice

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CTSR Series

Primary nominal residual current and primary nominal current

The primary nominal residual current is the sum of the instantaneous values of all currents flowing through the aperture of the

transducer.

The primary nominal current is the current flowing through any conductor placed into the aperture of the transducer.

The presence of a primary nominal current DC or AC leads to an additional uncertainty.

For example, with a primary nominal current of 30 A the uncertainty referred to primary is typical 4.3 mA.

CTSR transducer in Test mode

When the V

transducer exhibits a fixed value (see specification) as if it measured a primary test current.

The activation time of test mode is min 30 ms. The CTSR transducer can be maintained in test mode as long as needed for

checking that it is fully operating.

CTSR transducer in Degauss mode

The CTSR transducers go in degauss mode automatically at each power on or on demand by using the V

At power on:

A degauss is automatically generated at each power on of the CTSR transducer; during degaussing the output voltage V

maintained at 0.3 V typ. (max 0.5 V). After c.a. 110 ms, the output voltage V

relation with the measured primary current.

Using V

When the pin V

generates an automatic degauss.

The activation of degauss takes typically 40 µs after releasing V

Isolation around the CTSR transducer housing

Due to the joint between the case and the cover of the CTSR transducer, there is some isolation distance to respect when primary

conductors pass around the CTSR housing.

The figure below shows the joint and the apertures where the clearance between the secondary part inside the CTSR transducer

and the surface of the housing is 3 mm (label E).

V

1 V

30 ms

0.7 V (0.3-P) or

0.4 V (0.6-P)

1.7 V (0.3-P) or

1.1 V (0.6-P)

110 ms

-2 V

Test mode

Degauss mode

-2.5 V

2.5 V

Measuring

Measuring