HK688P True RMS Digital Power Clamp Meter combines electrical measurement, power analysis and three-phase system testing in one handheld instrument. Developed for electricians, maintenance teams and equipment technicians, it measures AC current up to 600A without disconnecting the conductor and supports voltage testing up to 1000V DC or 750V AC.
Unlike a basic clamp multimeter, the HK688P can evaluate active power, apparent power, reactive power and power factor. Dedicated voltage, current and power frequency functions provide additional information when inspecting motors, distribution panels, industrial equipment and other AC loads.
A 9999-count EBTN display presents readings clearly, while True RMS technology supports more dependable AC measurements on both conventional and electronically controlled systems. The meter also includes VFD voltage and current measurement, inrush-current capture, harmonic testing and three-phase sequence detection.
With a CAT IV 600V safety rating, full-range overload protection and a 34mm jaw opening, the HK688P is built for demanding electrical inspection and troubleshooting tasks.
Highlight
- Integrated Power Measurement
Measure active, apparent and reactive power directly, then evaluate power factor without switching between several separate instruments.
- True RMS AC Testing
Obtain more representative voltage and current readings when working with distorted or non-sinusoidal AC waveforms.
- 600A Non-Contact Current Measurement
The clamp jaw measures AC current up to 600A without opening the circuit, making load checks faster and more convenient.
- VFD Measurement Mode
Dedicated AC voltage and AC current functions help technicians inspect circuits associated with variable-frequency drives.
- Three-Phase Sequence Detection
Identify phase order when installing, commissioning or servicing three-phase motors and electrical distribution equipment.
- Inrush Current Capture
Record startup current from motors and other high-demand loads to investigate tripping, difficult starts or equipment-loading conditions.
- Complete Electrical Power Data
Review active power, apparent power, reactive power, power factor and related frequency measurements from a single portable meter.
- Harmonic Measurement
Check harmonic conditions that may affect power quality, equipment temperature or the operation of sensitive electrical devices.
- LoZ Voltage Input
Low-impedance voltage measurement helps reduce misleading readings caused by capacitively coupled or ghost voltages.
- MAX/MIN and Peak Hold
Capture changing electrical values and retain important maximum, minimum or peak readings during troubleshooting.
- NCV and Live-Wire Detection
Perform preliminary voltage screening and identify live conductors before making direct-contact measurements.
- 9999-Count EBTN Display
The high-count display provides detailed readings and includes a backlight, unit icons and a built-in flashlight for field use.
- CAT IV 600V Protection
Full-range overload protection and a CAT IV 600V rating support professional measurements in demanding electrical environments.
Technical Specifications
| Specification | HK688P |
|---|---|
| Meter Type | True RMS digital power clamp meter |
| Display Count | 9999 counts |
| DC Voltage | Up to 1000V |
| AC Voltage | Up to 750V |
| LoZ DC/AC Voltage | 1000V DC / 750V AC |
| AC Clamp Current | Up to 600A |
| DC Low Current | Up to 2000µA |
| Resistance | Up to 100MΩ |
| Capacitance | Up to 99.9mF |
| Frequency Range | Up to 10kHz |
| Temperature Range | Up to 400°C / 750°F |
| Bandwidth | 1000Hz |
| Duty Cycle | 0.1%-99.9% |
| Active Power Measurement | Supported |
| Apparent Power Measurement | Supported |
| Reactive Power Measurement | Supported |
| Power Factor Measurement | Supported |
| Voltage Frequency Measurement | Supported |
| Current Frequency Measurement | Supported |
| Power Frequency Measurement | Supported |
| Harmonic Measurement | Supported |
| VFD Measurement | AC voltage / AC current |
| Three-Phase Sequence Detection | Supported |
| Inrush Current | Supported |
| Peak Hold | Supported |
| MAX/MIN Recording | Supported |
| Relative Measurement | Supported |
| Diode Test | Supported |
| Continuity Test | Supported |
| NCV Detection | Supported |
| Live-Wire Recognition | Supported |
| Data Hold | Supported |
| Over-Range Indication | Supported |
| Full-Range Overload Protection | Supported |
| Range Selection | Automatic / Manual |
| Display Type | EBTN display with unit icons |
| Backlight | Supported |
| Built-In Flashlight | Supported |
| Automatic Power-Off | Supported |
| Wake-Up Function | Supported |
| Low-Battery Indication | Supported |
| Safety Rating | CAT IV 600V |
| Input Impedance | ≥10MΩ |
| Jaw Opening | 34mm |
| Display Area | 36 × 50.5mm |
| Power Supply | 3 × 1.5V AAA batteries |
| Product Dimensions | 225 × 75 × 35mm |
| Product Weight | Approximately 250g |
Application
Industrial Power Analysis
Measure current, voltage, real power, reactive power and power factor when assessing machinery, production equipment and facility electrical loads.
Motor Startup Diagnostics
Use inrush-current and peak-hold functions to investigate excessive starting current, protective-device trips or abnormal motor behavior.
Variable-Frequency Drive Maintenance
Inspect VFD-controlled motors, pumps, fans and automation equipment using the dedicated AC voltage and current measurement mode.
Three-Phase Equipment Installation
Confirm phase sequence before commissioning motors, compressors, HVAC equipment or other three-phase machinery.
Electrical Distribution Inspection
Evaluate circuits in switchboards, distribution cabinets and service equipment where a CAT IV 600V instrument is appropriate.
Power Quality Troubleshooting
Use harmonic, frequency and power-factor measurements to investigate inefficient loads, waveform distortion and unstable system performance.
Commercial Building Maintenance
Perform scheduled checks on lighting circuits, air-conditioning systems, elevators, pumps and electrical distribution equipment.
Electrical Appliance Testing
Measure operating current, power consumption and startup behavior when servicing high-load appliances or workshop equipment.
Technical Training
Demonstrate the relationships among voltage, current, active power, reactive power, apparent power and power factor in electrical laboratories.
