EMCheck® LSMZ I | EMC - Measuring clamp for leakage current

The EMCheck® LSMZ I is a leakage current clamp designed for measuring shield and leakage currents in industrial automation installations. Where intermittent communication errors and unexplained fieldbus failures trace back to electromagnetic interference rather than the bus itself, the LSMZ I provides the measurement capability to identify the real source of the problem. With an adjustable measuring range from 30 μA to 100 A across the 5 Hz–1 kHz frequency band, it covers both low-frequency power line interference and higher-frequency shield currents that degrade data cable shielding effectiveness over time.

Key Features
Adjustable measuring range from 30 μA to 100 A across five measurement levels, spanning the 5 Hz–1 kHz frequency range. The lower range is specifically suited for measuring shield currents on data cables, where values above 40 mA typically indicate issues with equipotential bonding or external interference sources that require corrective action.

Large 2.8 cm jaw opening that allows cables to pass through easily, enabling comfortable, single-handed measurements even in tight installation positions and congested cable trays where access is limited. The wide jaw accommodates most industrial cable diameters without requiring cable disconnection.

Hold function for capturing and retaining peak or maximum current readings during continuous measurement. The hold capability is particularly useful for identifying intermittent interference events and recording maximum current values without requiring continuous observation of the display.

Multimeter clamp functionality that combines leakage current measurement with the standard features of a current measurement clamp, reducing the number of instruments required for EMC commissioning and troubleshooting tasks.

Illuminable display for reading measurements in low-light environments typical of control cabinets and machine bases.

Application-specific measurement guidance based on established Indu-Sol field experience: shield currents below 40 mA are generally acceptable regardless of machine specifications, values between 40 mA and 150 mA indicate a need to improve equipotential bonding or eliminate the interference source, and values above 150 mA indicate a decrease in shielding effectiveness and risk of electrical overload to connected devices.

Common Applications
EMC commissioning verification on new PROFIBUS, PROFINET, or industrial Ethernet installations, confirming that cable shielding and equipotential bonding meet acceptable limits before the system goes into production.

Troubleshooting intermittent fieldbus errors where the communication issue is suspected to originate from electromagnetic interference rather than the bus hardware or configuration. Shield current measurement localizes the interference path so corrective action can be targeted accurately.

Routine maintenance checks in manufacturing environments with high electromagnetic noise sources — such as variable frequency drives, servo systems, welding equipment, and large motors — where shielding degradation develops gradually over time.

Insulation fault localization for identifying unintentional earth connections and potential causes of earth-leakage circuit breaker trips in industrial control systems.

Acceptance testing documentation for system integrators and machine builders verifying EMC conformity of completed installations prior to customer handover.

Technical Specifications
-Measuring range: 30 μA–100 A (5 adjustment levels)
-Frequency range: 50/60 Hz and 5 Hz–1 kHz
-Jaw opening: 2.8 cm
-Display: Illuminable with hold function
-Guideline values: <40 mA acceptable; 40–150 mA corrective action recommended; >150 mA shielding effectiveness compromised
-Limit values: Max. 150 mA for cable screens; 300 mA for equipotential bonding conductors; 5% of phase current for protective conductors within cable

The EMCheck® LSMZ I gives maintenance teams and commissioning engineers a fast, practical method for measuring and verifying shield current levels — turning an often-invisible source of industrial network problems into a measurable, addressable condition.

Learn more here: https://indusolamerica.com/emc/emcheck-lsmz-i-emc-measuring-clamp-for-leakage-current-122010005/