Klein Tools is well known for creating reliable, professional-grade test instruments used by electricians and HVAC technicians worldwide.
Two of their most popular mid-range clamp meters, the CL390 and CL220, share a similar look and feel but serve slightly different purposes. Let’s explore how they compare in performance, features, and best-fit applications.
🔍 Overview
The Klein CL390 is a True RMS AC/DC clamp meter built for technicians who deal with both alternating and direct current. It’s ideal for those working in electrical maintenance, solar, battery systems, or automotive environments.
The Klein CL220 is a simpler AC-only clamp meter designed mainly for HVAC and facility maintenance professionals. It’s straightforward, accurate, and includes temperature measurement for quick system diagnostics.
📊 Specification Comparison
| Feature | Klein CL390 | Klein CL220 |
|---|---|---|
| Current Measurement | 400 A AC/DC | 400 A AC |
| Voltage Measurement | 600 V AC/DC | 600 V AC/DC |
| Resistance | 40 MΩ | 20 MΩ |
| Capacitance | 4000 µF | Not specified |
| Temperature Measurement | –40°F to 1832°F | –40°F to 1832°F |
| Display Count | 4000 (reverse contrast) | 2000 (backlit LCD) |
| Non-Contact Voltage (NCV) | Yes | Yes |
| Safety Rating | CAT III 600 V | CAT III 600 V |
| Drop Protection | 2 m (6.6 ft) | 2 m (6.6 ft) |
| Jaw Opening | 1.6 in (41 mm) | 1.6 in (41 mm) |
| True RMS | Yes | Yes |
| Dimensions | 8.4 × 3.5 × 1.5 in | 8.4 × 3.5 × 1.5 in |
⚙️ Performance and Features
Klein CL390
The CL390 is built for professionals who need flexibility. It can measure both AC and DC current, making it useful for a wide range of applications such as residential wiring, industrial maintenance, and solar system troubleshooting. The True RMS accuracy ensures reliable readings on complex electrical loads, while its reverse-contrast display enhances readability in both bright and dim environments.
It includes all standard measurement modes — continuity, frequency, diode testing, capacitance, and microamps — making it a versatile choice for fieldwork.
Klein CL220
The CL220 focuses on simplicity and reliability. It measures AC current only but includes a built-in thermocouple input for temperature testing, which is essential for HVAC technicians. The 2000-count display and basic measurement functions make it easy to use without overwhelming menus or buttons.
For general AC electrical diagnostics, the CL220 provides quick, accurate readings without unnecessary complexity.
🧩 Design and Build Quality
Both meters share the same rugged Klein design, including a reinforced housing, rubberized grips, and 2-meter drop protection. Each unit is compact and lightweight enough to fit comfortably in a tool pouch. The rotary selector switch is firm and precise, allowing quick transitions between measurement modes even when wearing gloves.
The CL390’s reverse-contrast screen provides a noticeable visibility advantage outdoors or under bright lights. The CL220’s standard backlit display, while still clear, is better suited for indoor work.
💡 Best Use Cases
| User Type | Recommended Model | Reason |
|---|---|---|
| Electricians | CL390 | Handles both AC and DC circuits with True RMS accuracy |
| Solar and Battery Technicians | CL390 | DC current measurement and broad functionality |
| HVAC Technicians | CL220 | Built-in temperature measurement, simple interface |
| General Maintenance | CL220 | Easy to use and affordable for AC work |
🏁 Verdict
Both the CL390 and CL220 are excellent, professional-grade clamp meters built with Klein’s trademark durability.
Choose the CL390 if you need a versatile tool that can measure both AC and DC current, ideal for electrical, solar, or industrial applications.
Choose the CL220 if you primarily work with AC circuits and want an easy-to-use, temperature-ready meter tailored for HVAC and maintenance professionals.
In short, the CL390 is your all-purpose powerhouse, while the CL220 is your reliable, no-nonsense daily driver for AC diagnostics.