Klein Tools CL320 HVAC Digital Clamp Meter, AC Auto-Ranging 400 Amp

No. The clamp on the CL320 reads AC current only, up to 400 A AC. It does measure DC voltage to 600V and DC microamps to 200 uA through the test leads, which covers flame-sensor rectification checks on furnaces, but there is no DC amp clamp function. For DC motor current you need a Hall-effect DC-capable clamp.

The CL320 carries a CAT III 600V rating with Class 2 double insulation and is CE certified. That covers distribution panels, feeders, and fixed equipment like rooftop units up to 600V, including 480V three-phase gear. It is not rated CAT IV, so service entrance, utility drops, and line-side-of-main work are outside its rating.

Temperature is built in. The CL320 reads from -40 to 1832 F (-40 to 1000 C) using a K-type thermocouple probe, and the thermocouple is in the box. That handles supply/return delta-T, line temperature for superheat and subcooling, and flue temps without carrying a second instrument.

The CL320 ships with a carrying case, test leads with CAT III/CAT IV safety caps, a K-type thermocouple, instructions, and the 3 AAA batteries it runs on. So it is ready to use out of the box. The only add-on Klein calls out is the magnetic hanger for hands-free work, Cat. No. 69445 or 69417, which is sold separately.

Yes, it uses true RMS measurement, which is what you need on distorted waveforms from VFDs, ECM blower motors, and electronic ballasts. An averaging meter will read low on those loads. The CL320 also auto-ranges, so you are not stepping through ranges while holding a clamp in a hot panel.

There is a non-contact voltage tester built into the clamp jaw, so you can sweep a wire or a disconnect for live AC before you touch anything with a lead. It is a go/no-go presence check, not a measurement. For an actual value, the leads read AC and DC voltage to 600V.

Through the test leads the CL320 covers resistance to 40 megohms, capacitance to 4000 uF, frequency from 10 Hz to 60 kHz, duty cycle, diode test, continuity, and DC microamps. The capacitance range matters for HVAC: it checks run and start capacitors directly, so you are not guessing at a bulging can.

It is built to survive a 6.6 foot (2 m) drop, with an ABS housing, and it weighs 0.615 lbs so it is not a burden clipped to a belt or set on a unit. Overall it runs 8.45 x 3.5 x 1.5 inches, which fits the included case and most tool bag pockets.

Yes. The display is a 4000-count backlit LCD measuring 1.57 x 0.87 inches, so it reads in an unlit crawlspace or attic. For hands-free work there is a test lead holder on the side of the clamp, and Klein offers a magnetic hanger, Cat. No. 69445 or 69417, to hang the meter off the unit while you clamp. Data Hold and Max/Min let you capture a reading in an awkward spot and read it after you pull your hands out.

Auto power off kicks in after 10 minutes of inactivity to save the 3 AAA batteries. If you are logging a long compressor cycle, keep that in mind. There is also a low battery indicator and a battery compartment you can get into without disassembling the meter.