HIOKI AC Leakage Clamp Meters

A. Product Overview

The HIOKI CM4000 Series is designed for accurate leakage current measurement without disconnecting electrical wiring. By clamping around a conductor or multiple conductors, technicians can identify unwanted current leakage that may indicate insulation deterioration, wiring faults, grounding problems or equipment abnormalities.

The series includes:

HIOKI CM4001
Compact AC leakage clamp meter suitable for leakage current and general load current measurement. It supports current measurement up to 600 A and features slim jaws for working in crowded electrical panels.

HIOKI CM4002
High accuracy leakage clamp meter with a 40 mm jaw diameter, designed for measuring very small leakage currents and AC load current up to 200 A. It is suitable for advanced maintenance and troubleshooting applications.

HIOKI CM4003
Advanced leakage clamp meter for applications requiring detailed monitoring and analysis. It supports waveform output, RMS output and external power operation, making it suitable for extended leakage current monitoring.

Depending on the model, the CM4000 Series includes functions such as True RMS measurement, comparator indication, low pass filtering, event recording, frequency measurement, inrush current measurement and optional wireless communication using the HIOKI Z3210 Wireless Adapter.

B. Working Principle

The HIOKI CM4000 Series measures AC current by detecting the magnetic field generated around an electrical conductor.

When the clamp jaws are placed around a single conductor, the meter measures the current flowing through that conductor.

For earth leakage current measurement, the clamp can be placed around multiple active conductors together. Under normal operating conditions, the current flowing through the conductors should balance. Any difference represents residual or leakage current flowing through another path, such as earth or equipment grounding.

The meter converts this detected magnetic field into an electrical measurement and displays the leakage current value.

True RMS technology enables accurate measurement even when the current waveform is distorted by equipment such as inverters, switching power supplies, variable frequency drives and electronic loads.

C. Why It Is Used

The HIOKI CM4000 Series is used to detect electrical leakage before it causes equipment failure, unwanted protection trips or electrical safety problems.

Typical applications include:

• Detecting earth leakage current
• Identifying insulation deterioration
• Troubleshooting RCD and GFCI tripping
• Checking electrical equipment for abnormal leakage
• Preventive maintenance of electrical installations
• Measuring AC load current
• Detecting intermittent leakage faults
• Monitoring leakage current over extended periods
• Inspecting industrial machinery and electrical panels
• Diagnosing problems in inverter driven and electronically controlled equipment

Leakage current measurement can help maintenance teams locate developing electrical problems without immediately shutting down equipment or disconnecting wiring.

D. Suitable Buyers

The HIOKI CM4000 Series AC Leakage Clamp Meters are suitable for:

• Electrical maintenance engineers
• Industrial maintenance teams
• Electrical contractors
• Facility management companies
• Electrical testing and inspection professionals
• Panel builders
• Machine maintenance engineers
• Factory maintenance departments
• HVAC service engineers
• Building maintenance technicians
• Utility maintenance teams
• Electrical safety inspectors
• RCD and GFCI troubleshooting professionals
• Preventive maintenance service providers
• Automation and instrumentation engineers

Frequently Asked Questions

What is the HIOKI CM4000 Series?

The HIOKI CM4000 Series is a range of True RMS AC leakage clamp meters designed for measuring small leakage currents and AC load current in electrical installations and industrial equipment.

Which models are included in the HIOKI CM4000 Series?

The commonly referenced models include HIOKI CM4001, CM4002 and CM4003.

What is the difference between HIOKI CM4001, CM4002 and CM4003?

The CM4001 is a compact model suitable for general leakage and load current measurement and can measure higher load currents. The CM4002 is designed for high accuracy leakage current measurement with a 40 mm jaw. The CM4003 adds advanced monitoring capabilities such as waveform output, RMS output and external power support.

Can HIOKI CM4000 Series meters measure earth leakage current?

Yes. These meters are specifically designed for measuring AC leakage and residual current in electrical systems.

Can the CM4000 Series measure normal load current?

Yes. The meters can measure AC load current in addition to small leakage currents. The supported maximum current depends on the selected model.

What is True RMS measurement?

True RMS measurement calculates the effective value of AC current even when the waveform is distorted. This is important when testing modern electrical equipment containing inverters, switching circuits and electronic loads.

Can these meters help troubleshoot RCD trips?

Yes. Leakage current measurement can help technicians identify circuits or equipment responsible for excessive leakage that may cause RCD or GFCI devices to trip.

Can HIOKI CM4000 meters measure very small leakage currents?

Yes. The CM4000 Series is specifically designed for sensitive leakage current measurement. Models such as the CM4002 and CM4003 can detect very small currents required for detailed electrical troubleshooting.

What is the jaw size of the HIOKI CM4002 and CM4003?

The HIOKI CM4002 and CM4003 feature approximately 40 mm clamp jaw openings, making them suitable for clamping around larger conductors and cable groups.

Does the HIOKI CM4000 Series support wireless communication?

Selected models can support wireless communication when used with the optional HIOKI Z3210 Wireless Adapter.

What is GENNECT Cross?

GENNECT Cross is HIOKI's application for transferring, displaying, recording and managing measurement data from compatible HIOKI instruments.

Can the HIOKI CM4000 Series be used for preventive maintenance?

Yes. Regular leakage current testing can help identify insulation deterioration, grounding abnormalities and developing electrical faults before they result in unexpected equipment shutdowns.

Can the CM4003 be used for continuous leakage monitoring?

The CM4003 is particularly suitable for advanced monitoring applications because it provides waveform output, RMS output and external power supply capability.

Where are HIOKI CM4000 Series leakage clamp meters commonly used?

They are commonly used in factories, commercial buildings, electrical panels, industrial machinery, HVAC systems, production facilities and electrical maintenance applications.