When it comes to choosing a clamp meter, Klein Tools offers several excellent options for both electricians and HVAC technicians. The CL320 and CL390 are two of the most popular mid-range models, both offering reliable performance and rugged build quality. But which one fits your needs best? Let’s take a closer look.
🧰 Overview
The Klein CL320 is built with HVAC and refrigeration professionals in mind. It combines standard electrical measurements with temperature readings, making it a go-to tool for technicians who work on cooling and heating systems.
The Klein CL390, on the other hand, is a more general-purpose clamp meter that measures both AC and DC current. It’s ideal for electricians, solar installers, and anyone who works on systems involving batteries or DC circuits.
🔍 Key Specifications
| Feature | Klein CL320 | Klein CL390 |
|---|---|---|
| Focus Area | HVAC applications | General electrical and DC systems |
| Current Measurement | 400 A AC | 400 A AC/DC |
| Voltage Measurement | 600 V AC / 600 V DC | 600 V AC / 600 V DC |
| Temperature Measurement | Yes, with thermocouple | Yes, with thermocouple |
| Non-Contact Voltage (NCV) | Yes | Yes |
| Resistance / Continuity / Frequency | Yes | Yes |
| Display Type | 4000 count backlit LCD | 4000 count reverse-contrast LCD |
| Drop Protection | 2 meters | 2 meters |
| Safety Rating | CAT III 600 V | CAT III 600 V |
| Jaw Opening | 1.6 in (41 mm) | 1.6 in (41 mm) |
| Price Range | 💲Check Price | 💲Check Price |
⚙️ Performance Comparison
Klein CL320 – For HVAC Technicians
The CL320 is designed primarily for HVAC work. It measures AC current, temperature, resistance, and continuity — making it perfect for diagnosing compressors, motors, and control boards. The integrated thermocouple allows quick temperature checks on coils, lines, or sensors. It’s accurate, simple to use, and tough enough for field work.
The main limitation is that it measures AC current only, which means it’s not ideal for DC applications such as solar, automotive, or battery systems.
Klein CL390 – For Electricians and General Use
The CL390 adds DC current measurement to the mix, expanding its versatility. It’s better suited for electricians and general maintenance workers who might need to test both AC and DC circuits. The reverse-contrast LCD display provides improved visibility in dim lighting conditions, and the non-contact voltage feature is handy for quick safety checks.
While it includes temperature measurement, it doesn’t have the HVAC-centric design focus of the CL320, so it might not be as convenient for dedicated HVAC technicians.
🧩 Build Quality and Design
Both models share Klein’s rugged design philosophy — rubberized housing, solid rotary selector switch, and wide clamp jaws. Each has a 2-meter drop rating, ensuring durability on the job. The CL390’s reverse-contrast display makes it easier to read in both bright sunlight and dark panels, giving it a slight advantage in visibility.
🧠 Ease of Use
Klein clamp meters are known for their intuitive layouts and single-handed operation. Both models feature auto-ranging, backlit screens, and simple function buttons. The CL320’s layout includes easy temperature access, while the CL390 adds DC current measurement without complicating the interface.
💬 Best For
| User Type | Recommended Model | Why |
|---|---|---|
| HVAC Technicians | CL320 | Temperature measurement and HVAC-focused design |
| Electricians | CL390 | AC/DC measurement, better suited for wiring and panels |
| Solar or Battery Technicians | CL390 | Includes DC current support |
| General Maintenance | CL390 | Versatile all-purpose clamp meter |
🏁 Verdict
Both clamp meters deliver outstanding value for their price, but they serve different needs.
- Choose the Klein CL320 if you’re an HVAC or refrigeration technician who frequently measures temperature and AC current.
- Choose the Klein CL390 if you’re an electrician, solar installer, or general technician who needs both AC and DC current measurement.
In short, the CL320 is a specialized HVAC meter, while the CL390 is a versatile all-around tool that bridges the gap between residential and industrial electrical work.