The HK888B is a professional-grade, 6000-count True RMS clamp meter engineered specifically for high-voltage photovoltaic (PV) systems and industrial power applications. Capable of measuring up to 2000V DC and 2000A DC/AC, it is one of the few handheld meters equipped to handle the full range of solar installation demands—from individual panel diagnostics to string and inverter testing. With advanced features like AC+DC True RMS, LoZ (Low Impedance) mode, VFD, inrush current, and a CAT III 1500V / CAT IV 1000V safety rating, the HK888B ensures accurate, reliable, and safe measurements in the harshest electrical environments.
Features (HK888B)
PV-Optimized High Voltage Range: Measures DC voltage up to 2000V (CAT III 1500V / CAT IV 1000V) – ideal for series-connected solar strings.
Bidirectional DC Current: Captures 2000A DC for charging/discharging in battery storage and PV arrays.
True RMS AC+DC: Accurately measures distorted waveforms on inverter outputs (both AC and DC components simultaneously).
Flex Clamp Input: Supports an external flexible current probe for measuring up to 3000A in tight spaces.
Low Impedance (LoZ) Mode: Eliminates ghost voltages to prevent false readings on long PV cables.
Specialty Modes:
VFD Mode: For variable frequency drive motor signals.
Inrush Current: Captures motor/generator startup surges.
Peak Hold: Captures transient voltage/current spikes.
Rugged & Safe: Double-colored flame-retardant ABS housing, built-in flashlight, NCV, live wire recognition.
Large Jaw Opening: Fits large gauge battery cables and busbars.
Specification
| Function | Range | Accuracy |
|---|---|---|
| DC Voltage | 600mV | ±(0.5% + 3d) |
| 6/60/600V | ±(0.7% + 3d) | |
| 2000V | ±(0.7% + 3d) | |
| AC Voltage (True RMS) | 6/60/600V | ±(1.0% + 5d) |
| 1500V | ±(1.0% + 10d) | |
| AC+DC Voltage | 6/60/600V | ±(1.5% + 5d) |
| 2000V | ±(2.5% + 5d) | |
| LoZ AC/DC | 1000V | ±(2.0% + 5d) |
| DC Current | 6/60/600/2000A | ±(2.5% + 5d) |
| AC Current (True RMS) | 6/60/600/2000A | ±(3.0% + 8d) |
| AC+DC Current | 6/60/600/2000A | ±(3.0% + 8d) |
| Flex Clamp Current | 600/3000A | ±(2.5% + 5d) |
| Resistance | 600Ω | ±(1.0% + 2d) |
| 6k/60k/600k/6MΩ | ±(0.6% + 2d) | |
| 60MΩ | ±(2.5% + 5d) | |
| Capacitance | 10nF | ±(3.0% + 5d) |
| 100n/1u/10u/100uF | ±(3.5% + 5d) | |
| 1m/10m/100mF | ±(10% + 5d) | |
| Frequency | 10Hz ~ 100kHz | ±(0.5% + 2d) |
| Duty Cycle | 0.1% ~ 99.9% | Reference |
| Temperature (°C) | -40°C ~ 0°C | ±4°C |
| 0°C ~ 400°C | ±(2.0% + 3°C) | |
| 400°C ~ 1000°C | ±(3.0% + 3°C) | |
| Temperature (°F) | -4°F ~ 50°F | ±6°F |
| 50°F ~ 750°F | ±(2.0% + 5°F) | |
| 750°F ~ 1832°F | ±(3.0% + 5°F) |
General Specifications
| Parameter | Details |
|---|---|
| Display Count | 6000 counts (3 5/6 digits) |
| True RMS | Yes (AC, AC+DC) |
| Jaw Opening | Φ60.5 mm (fits large cables) |
| Safety Rating | CAT III 1500V / CAT IV 1000V |
| Power Supply | 1.5V (AA) × 3 |
| Auto Power Off | Yes (selectable) |
| Dimensions / Weight | 285×105×44mm / ~625g |
Application
Solar PV Installation & Maintenance:
Measuring string DC voltage (up to 2000V) and current (up to 2000A).
Verifying inverter AC/DC output and efficiency.
Tracing ground faults and open circuits in combiner boxes.
Battery Energy Storage Systems (BESS):
Monitoring charge/discharge DC current of battery racks.
Testing busbar voltage and cell balancing.
Industrial Electrical:
Measuring inrush current on large motors, pumps, and HVAC compressors.
Diagnosing VFD-driven systems (VFD mode).
High-capacity capacitance testing for power factor correction.
EV & High-Power DC Systems:
Testing DC-DC converters and traction battery packs in electric vehicles.
Utility & Renewable Energy Labs:
Accurate AC+DC waveform analysis on hybrid inverter outputs.
FAQ (Frequently Asked Questions)
Q1: Can the HK888B measure DC current?
✅ Yes. Unlike many standard clamp meters, the HK888B measures DC current up to 2000A, essential for PV strings, battery banks, and EV systems.
Q2: What is the maximum voltage I can safely measure?
✅ 2000V DC / 1500V AC with a safety rating of CAT III 1500V / CAT IV 1000V – compliant with high-voltage solar standards.
Q3: Why do I need AC+DC True RMS?
✅ Solar inverters output PWM or modified sine waves containing both AC and DC components. AC+DC mode gives you the true total RMS value (heating equivalent) rather than just the AC component.
Q4: Can I use the HK888B without breaking the circuit?
✅ Yes. The clamp jaw (Φ60.5mm) allows non-contact current measurement. For voltage, you still need to probe test points.
Q5: Does it work with a flexible current probe?
✅ Yes. It has a dedicated Flex Clamp input supporting up to 3000A (accuracy ±2.5%+5d), useful for tight busbars or large conductors.
Q6: What is LoZ mode used for?
✅ Low Impedance (LoZ) mode places a low-impedance load on the circuit, draining induced ghost voltages that can cause false readings on long, unloaded PV cables.
Q7: How do I capture motor starting current?
✅ Use the Inrush Current Test mode. Clamp the meter around the conductor, then start the motor – the meter automatically captures the initial surge.
Q8: What accessories are included?
✅ Typically includes: test leads, thermocouple (for temperature), batteries (3×AA), user manual, and a carrying case. (Flex clamp probe optional.)
Q9: Is the meter durable for outdoor solar farms?
✅ Yes. It features a double-colored, flame-retardant ABS housing, built-in flashlight, and robust construction. (Check IP rating – likely IP54 or similar, though not specified.)
Q10: How is HK888B different from HK888A / HK888D?
✅
HK888A: AC current only (no DC current), lower CAT rating (likely CAT III 1000V).
HK888D: Has DC current but may lack AC+DC mode and Flex input.
HK888B: Full PV package – DC current + AC+DC True RMS + Flex input + 2000V DC + CAT III 1500V.