Eigenschaften
Continuity with buzzer, test current	≤ 1 mA
Continuity with buzzer, frequency	-
Dimensions / weight	163 x 64 x 40 mm / 210 g

The two-pole voltage tester C.A 742 from Chauvin Arnoux is a specialised measuring instrument for the safe verification of de-energised conditions in electrical installations. It serves electrical specialists as a reliable tool before maintenance or installation work to avoid electrical hazards. The device complies with standard IEC 61243-3 Edition 3 and is suitable for use in installation categories CAT IV 600 V, both indoors and outdoors. The IP65 protection rating of the housing ensures dust-tight and splash-proof conditions, enabling use under demanding environmental conditions. The operating temperature ranges from -15 °C to +45 °C at a relative humidity of 20 to 95 %.

Applications

The C.A 742 is primarily used to verify de-energised conditions in electrical installations, especially before work on power distribution networks. It enables detection of live conductors (phase) with only one test probe, making work more efficient. Additionally, it can indicate the rotation direction in three-phase networks up to 400 Hz, which is relevant for commissioning or maintenance of motors. The continuity test checks the electrical conductivity of conductors, triggering an optical and acoustic indication when resistance is below 100 Ω.

Functions and Equipment in Detail

The device detects voltages in the range of 12 V AC to 690 V AC (frequency 16 2/3 Hz to 800 Hz) as well as 12 V DC to 750 V DC. The voltage type (AC/DC) is indicated optically via LED displays, with polarity also being detected. A redundant safety system is implemented via the red ELV-LED (Extra Low Voltage), which flashes when voltages exceed 50 V AC or 120 V DC. The faster the LED flashes, the higher the applied voltage. The detachable test probes and test leads allow flexible adaptation to different application scenarios. The test probes are equipped with springs providing a contact force of 10 N to ensure secure contact even when using personal protective equipment (PPE).

Technology Explained Simply

The voltage tester operates with an integrated self-test that checks all electrical circuits, power supply, displays, and the condition of the test leads. This ensures the device is functional before each use. Power is supplied by two 1.5 V batteries (type LR03), enabling 7500 measurements at 10 seconds each. The device's impedance exceeds 300 kΩ, ensuring high input resistance safety. The maximum current is 3.5 mA RMS, and the test current for continuity testing is ≤ 1 mA. The open-circuit voltage is ≤ 3.3 V, enhancing safety during continuity testing. The continuity test protection function extends up to 1000 V.

Compatibility and Accessories

Compatible accessories include detachable test probes with 2 mm Ø, test leads with test probes in IP2X configuration, protective caps for test probes, and adapters such as the C.A 753, which enables safe voltage testing at Schuko sockets. The IP2X accessories offer additional operator safety and are required in some countries. The test leads are equipped with 4 mm angled connectors and are rated for CAT IV 600 V. Lead lengths vary between 0.25 m and 1.5 m, with red and black colours used.

Mounting and Installation

The C.A 742 is designed as a handheld device and requires no mounting. The detachable test probes and test leads are simply attached to the corresponding connectors on the device. Operation is via buttons and LED displays, with the self-test recommended before each use. The device dimensions are 163 x 64 x 40 mm, and the weight is 210 g, enabling mobile and compact handling.

Operational Advantages

The C.A 742 offers high safety through the integrated self-test and redundant safety system with the ELV-LED. Intuitive operation via LED displays and acoustic signals (intermittent beep for voltage detection, continuous beep for continuity test) simplifies work. Detachable components increase flexibility and allow replacement in case of wear. Compliance with IEC 61243-3 and approval for CAT IV 600 V ensures suitability for professional environments. The IP65 protection rating allows use in harsh environments, including outdoors. Batteries are not included in the delivery scope.