HIOKI P2010 DC High Voltage Probe — CAT III 2000 V Solar

The Problem with Standard Test Leads on Modern Solar Installations

Australia’s solar sector has grown dramatically. Utility-scale and commercial rooftop installations operating at 1000 V and above are now the norm, with 1500 V DC string systems increasingly common on large ground-mount and commercial-scale arrays. The challenge? Most general-purpose clamp meters and multimeters are rated to CAT II or CAT III 1000 V — meaning they simply aren’t equipped for the transient overvoltages that can occur in these higher-voltage environments.

Using an under-rated instrument on a high-voltage PV array isn’t just a compliance issue — it’s a genuine electrocution risk. IEC 61730-1 (the standard for PV module safety qualification) explicitly classifies solar installations as Measurement Category III environments. If your instrument doesn’t match the category and voltage of the site, you’re working outside its safe operating envelope.

That’s the problem the HIOKI P2010 DC High Voltage Probe was designed to solve.

What the HIOKI P2010 Does

The P2010 is a DC high voltage probe accessory that plugs directly into compatible HIOKI clamp meters and digital multimeters via standard 4 mm banana terminals. Once connected, it upgrades the instrument’s measurement capability to CAT III 2000 V DC — pushing the voltage ceiling well beyond what most standalone meters can handle.

It works by scaling the input voltage through a precision 20 MΩ resistive divider network, delivering a proportionally reduced output signal to the connected meter. Depending on the instrument, the P2010 operates in either “DC High V Probe Mode” (for compatible clamp meters like the CM4373-50 and CM4375-50, and the DT4261 DMM) or “1/10 output rate mode” (for other compatible HIOKI DMMs).

The key point: the probe does the heavy lifting — handling the dangerous high-voltage input — while the meter simply reads the scaled output. The result is a measurement chain that’s safe, compliant, and accurate at voltages your standard test leads can’t touch.

Built for Australian Solar Professionals

For solar installers and commissioning engineers working to AS/NZS 5033 (Installation and Safety Requirements for PV Arrays) and IEC 62446-1 (Grid-Connected PV Systems — Minimum Requirements for Documentation, Commissioning Tests and Inspection), correct instrument categorisation is a fundamental requirement. The P2010’s CAT III 2000 V rating satisfies the overvoltage category requirements for PV string and combiner testing in large commercial and utility installations.

CEC accredited designers and installers working on systems with string voltages above 1000 V will find the P2010 fills a genuine gap in their test kit — it’s the accessory that makes a capable HIOKI clamp meter or DMM fully PV-system capable.

Key Benefits

Measurement Safety Without Compromise The P2010 carries a CAT III 2000 V rating — the same category as solar PV installations per IEC 61730-1. Overload protection is rated to 2200 V DC/AC for one minute between the input terminals. You’re not working at the ragged edge of your instrument’s limits; you have genuine safety margin built in.

Non-Intrusive Measurement — No System Shutdown Required One of the practical advantages of voltage probing over current-injection testing is that you can take live measurements without interrupting generation. The P2010 allows high-voltage DC string and array measurements while the system remains connected and generating. This is valuable for fault-finding, commissioning verification, and regular maintenance inspections without costly downtime.

Extends Your Existing HIOKI Instrument Investment If your team already carries HIOKI CM4373-50, CM4375-50, CM4371-50, CM4141-50, or DT4261/DT4281/DT4282 instruments, the P2010 is the most cost-effective way to add high-voltage PV measurement capability. You don’t need to purchase a dedicated high-voltage meter — the P2010 transforms your existing instrument into a fully rated 2000 V DC measurement solution.

Wide Operating Temperature Range Solar work happens outdoors, often in harsh Australian conditions. The P2010 operates from –25°C to +65°C, making it equally capable during a crisp winter commissioning job in the Victorian Alps or summer maintenance work on a rooftop array in Darwin.

Precision Input Resistance The 20 MΩ ±5.0% input resistance ensures the probe draws negligible current from the circuit under test — important when working with string configurations where load disturbance can affect readings and potentially trigger protection equipment.

Compatible Instruments

The P2010 is compatible with the following HIOKI instruments. Note that connection modes differ:

DC High V Probe Mode (direct 2000 V range):

• CM4141-50 AC Clamp Meter
• CM4371-50 AC/DC Clamp Meter
• CM4373-50 AC/DC Clamp Meter
• CM4375-50 AC/DC Clamp Meter
• DT4261 Digital Multimeter

1/10 Output Rate Mode (scaled reading):

• DT4252, DT4253, DT4255, DT4256
• DT4281, DT4282

Note: The P2010 requires a compatible HIOKI clamp meter or DMM, purchased separately. Always confirm your instrument model before ordering.

Application Use Cases

1. Utility-Scale and Commercial Solar PV Commissioning When commissioning a large-scale solar installation with string voltages at or approaching 1500 V DC, AS/NZS 5033 and IEC 62446-1 require measurement of open-circuit voltage and operating voltage for each string. The P2010 makes this task safe and straightforward — connect to your HIOKI clamp meter or DMM and verify string voltages with a CAT III rated instrument without improvised workarounds.

2. Fault Diagnosis on High-Voltage PV Strings String-level faults — failed bypass diodes, shading losses, degraded modules — often require live voltage measurements across strings and sub-arrays to isolate the fault. The P2010 allows this diagnostic work to be performed at full system voltage with confidence, without needing to de-energise the array.

3. Combiner Box and DC Distribution Inspections Combiner boxes on utility installations can see bus voltages above 1000 V DC. Verifying bus voltage, checking string input voltages, and confirming fuse/circuit breaker operation all require high-category measurement tools. The P2010 combined with a compatible HIOKI clamp meter gives technicians the right instrument for the task.

4. Maintenance Inspections on Aging Installations As Australia’s early large-scale solar installations approach 10+ years of operation, scheduled maintenance and performance inspections are increasingly common. Measuring degradation trends in string output voltage requires repeatable, accurate, high-voltage capable measurements — exactly what the P2010 delivers.

5. Safety Audits and Compliance Verification Safety officers and accredited auditors verifying PV system installations against AS/NZS 5033 or IEC 62446-1 need to document voltage measurements made with correctly rated instruments. The P2010’s CAT III 2000 V rating ensures the measurement chain meets the overvoltage category requirements specified in the applicable standards.

Technical Specifications

Combined Accuracy (with compatible instruments):

Included in the Box

• HIOKI P2010 DC High Voltage Probe ×1
• Instruction Manual ×1
• Operating Precautions ×1

Compatible HIOKI clamp meter or DMM must be purchased separately.

Optional: Carrying Case C0203 available separately.

Q: What is the HIOKI P2010 used for? The HIOKI P2010 is a DC high voltage probe accessory used to extend the voltage measurement capability of compatible HIOKI clamp meters and digital multimeters to 2000 V DC with a CAT III safety rating. It is primarily used for safe inspection, commissioning, and maintenance of high-voltage solar PV installations, including large-scale systems operating at 1500 V DC.

Q: What CAT rating do I need to measure solar PV installations? According to IEC 61730-1 (PV module safety qualification standard), solar PV installations are classified as Measurement Category III (CAT III) environments. Any instrument or probe used for voltage measurement on PV strings, combiners, or arrays must carry a CAT III rating appropriate to the system voltage. For modern 1500 V DC systems, a CAT III 1500 V or higher rating is required.

Q: Is 2000 V measurement safe for a 1500 V solar installation? Yes. Using a 2000 V rated probe like the HIOKI P2010 on a 1500 V DC solar installation provides a safe margin above the system’s operating voltage. The CAT III 2000 V rating also accounts for transient overvoltages — voltage spikes that can significantly exceed the nominal system voltage during switching events or fault conditions.

Q: Can I use my standard multimeter on a 1500 V solar installation? Standard multimeters rated to CAT III 1000 V or CAT II 1000 V are not suitable for direct measurement on solar PV strings operating at or above 1000 V DC. You either need a dedicated high-voltage meter, or an accessory like the HIOKI P2010 that extends a compatible meter’s rating to CAT III 2000 V.