LEM’s CTSR current transducers combine safety and high performance in solar installations
The CTSR family of transducers has been specifically designed to meet the latest safety standards that have been issued in respect of solar installations and inverters, namely VDE 0126-1-1, UL 1741, and IEC 60950-1. The devices are PCB mountable, lightweight (28g) components, with a 20.1 mm diameter aperture that easily accommodates multiple conductors. The residualcurrent capability measures the sum of all of the instantaneous currents flowing through the aperture, in single- or three-phase configurations. Conductors may be carrying primary currents of up to 30A/wire (AC or DC).
The CTSR 0.3-P and CTSR 0.6-P safely measure nominal currents of 300 and 600 mA
respectively, to a maximum accuracy of 1.9% and 1.5% respectively at +25°C ambient temperature, without offset, providing an analogue output to trigger a safety system in the event of a high leakage current. They both provide a high overload capability up to 3300A (for a pulse duration of 100μs, and with risetime of 500 A/μs), as well as a very high level of insulation between primary and measurement circuits, thanks to long creepage and clearance distances (11 mm), coupled with a CTI (comparative tracking index) of 600V.
These products can also be supplied with a primary inserted conductor (made up of 4 individual conductors), and in that configuration have the designation “CTSR xxx-TP”. CTSR-series transducers operate from a +5VDC supply and have a typical current consumption of just 17.8 and 18.1 mA unipolar when measuring 300 and 600 mA respectively as nominal primary residual current (CTSR 0.3-P and CTSR 0.6-P models); They provide access to their internal reference voltage, and to options such as self test and demagnetisation.
Models with higher nominal current range up to 3 ARMS to meet the needs of specific customers can be developed on request. As well as ensuring safety in solar inverter installations, LEM’s CTSR range is also ideal for a range of applications that includes symmetry fault detection in medium power inverters, failure detection in a range of power sources.
The transducers are CE marked, conform to the EN 50178 standard and are recognised for industrial applications with an operating temperature range of -40 to +105°C. LEM offers a fiveyear warranty for each transducer.