Best HVAC Clamp Meters
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Top pickUEi DL389B Dual DisplayCheck price
A clamp meter is the first thing most HVAC techs reach for, because amp draw tells you whether a motor or compressor is healthy before you open anything up. The catch is that clamp meters range from a basic amp clamp to a clamp that doubles as a full HVAC multimeter, and the price gap between them is large.
Quick answer: our top picks
- Best all-in-one for residentialProUEi DL389B Dual Display True-RMS HVAC Clamp Meter with TemperatureAmps, flame-sensor microamps, 4,000 uF capacitance and temperature in one clamp
- Lower-cost durable 600 A clampMid-rangeKlein Tools CL710 Digital Clamp Meter600 A AC/DC with capacitance and non-contact voltage at a mid price tier, but no microamps, so it is not a flame-sensor tool
- Best clamp for flame-sensor testsProFieldpiece SC440 True RMS Clamp MeterDC microamps, capacitance, temperature and inrush in a Fieldpiece clamp
- Best for commercial and VFD workPremiumFieldpiece SC680 Wireless Swivel Clamp Meter with Power600 A AC/DC swivel clamp with inrush, power and a CAT IV rating
- Best compact HVAC clampProFieldpiece SC260 Compact True-RMS Clamp MeterSmall Fieldpiece clamp with capacitance and temperature
Comparison at a glance
| Product | Best for | Amps | Microamps | Capacitance | Temperature | Price tier | |
|---|---|---|---|---|---|---|---|
| Top pickUEi DL389B Dual Display | Residential service, one-tool kit | 400 A AC | Yes, 2000 uA (test leads) | 4000 uF | Yes, to 752 F | Pro | Check price |
| Klein Tools CL710 | Durable 600 A clamp, mid price | 600 A AC/DC | – | Yes | – | Mid-range | Check price |
| Fieldpiece SC440 | One clamp that tests flame sensors | True RMS AC | Yes, DC | Yes | Yes | Pro | Check price |
| Fieldpiece SC680 | Commercial, VFD, wireless logging | 600 A AC/DC, with inrush | Yes, 1,000 uA DC | To 10 mF | Two Type K inputs | Premium | Check price |
| Fieldpiece SC260 | Small, light HVAC clamp | 400 A AC | – | Yes | Yes | Pro | Check price |
| Fluke 323 True-RMS Clamp Meter | Amp draw, paired with a meter | 400 A AC | No | No | No | Pro | Check price |
| Fluke 325 True-RMS Clamp Meter | Fluke fans who need DC amps | 400 A AC/DC | – | 1000 uF | Type K, to 752 F | Premium | Check price |
| Fieldpiece SC480 | Commercial power and phase work | 600 A | Yes, DC | Yes | – | Premium | Check price |
This guide sorts eight clamps by what they measure, not by brand. If you only buy one tool for amps, flame sensors and capacitors, look at the UEi DL389B. If you already own a Fluke 116, a simple Fluke 323 completes the pair. If you work on commercial equipment and variable-speed drives, the Fieldpiece SC680 is built for that.
What to look for in an HVAC clamp meter
- Amp range and jaw size for the work: 400 A covers residential; 600 A and a 1.4 in jaw help on commercial feeders
- DC amps if you service inverter/DC equipment or solar-assisted systems; many HVAC clamps are AC only
- Microamps through test leads for flame sensors, so the clamp can replace a separate multimeter
- Capacitance range big enough for start caps (2000 uF or more is comfortable)
- Type K temperature input, ideally two inputs for delta-T
- Inrush (LRA) capture for hard-starting compressors
- CAT III 600 V minimum; True-RMS for variable-speed equipment; wireless app logging if you write up jobs
Which clamp meter fits which tech
Residential service tech, one tool in the bag. The UEi DL389B covers all four of the checks you do most: amp draw on the jaw, flame-sensor microamps on the leads, capacitance high enough for large start capacitors, and temperature. The Fieldpiece SC440 and SC680 also list all four. The tradeoff is that the jaw reads AC amps only.
Residential tech who already carries a multimeter. A basic clamp is enough. The Fluke 323 reads True-RMS AC amps and little else, which is the point. Pair it with the Fluke 116 and you cover amps, microamps, capacitance and temperature across two tools.
Commercial and variable-speed work. Variable-frequency drives and ECM equipment are where a True-RMS clamp with a low-pass filter earns its price. Fieldpiece lists the SC680 with a low-pass filter, DC amps, inrush capture and a CAT IV 600 V / CAT III 1000 V rating.
Compact pick. The Fieldpiece SC260 is a compact HVAC clamp with capacitance and temperature. Check the missing items before you buy: Fieldpiece does not list microamps for it.
The clamp meters in detail
UEi DL389B Dual Display True-RMS HVAC Clamp Meter with Temperature
Best for: Residential HVAC techs who want a single clamp for amps, flame sensors and big start capacitors.
- 400 A AC (jaw); no DC amps listed
- AC/DC microamps to 2000 uA via test leads
- Capacitance to 4000 uF; resistance to 40 Mohm
- Temperature -22 to 752 F
- 1000 V DC / 750 V AC; True-RMS
Why it stands out
- 4000 uF capacitance covers large start capacitors
- Microamps for flame sensors
- Temperature input
- Dual display
Keep in mind
- AC amps only on the jaw
- CAT III 600 V, no CAT IV rating
Best for: Techs who want a durable 600 A clamp with capacitance at a mid price tier.
- 600 A AC/DC, auto-ranging, True RMS
- Voltage, resistance, continuity, frequency and capacitance
- Non-contact voltage detection in the jaw
- 6.6 ft drop rating and IP40 ingress protection
- Lighted dial and reverse-contrast display
Why it stands out
- 600 A AC/DC range with capacitance
- Built-in non-contact voltage detection
Keep in mind
- No microamp range listed, so it is not a flame-sensor clamp
Best for: Techs who want one clamp that also tests flame sensors.
- True RMS clamp meter for HVACR, accurate on VFD readings
- Temperature, capacitance and DC microamps for flame sensors
- Inrush current
- Non-contact voltage, high-voltage LED and continuity beeper
- Detachable leads with alligator tips
Why it stands out
- DC microamps, capacitance and temperature in a clamp
- Inrush current for motor start checks
Keep in mind
- Higher price tier than a basic amp clamp
Fieldpiece SC680 Wireless Swivel Clamp Meter with Power
Best for: Commercial and VFD-heavy techs who want one wireless clamp that also logs to the Job Link app.
- 600 A AC/DC swivel clamp with inrush
- True-RMS with low-pass filter for VAC and Hz (VFD work)
- Power (kW) measurement; phase rotation test
- Dual Type K temperature inputs; resistance to 50 Mohm; NCV
- CAT IV 600 V / CAT III 1000 V
Why it stands out
- Swivel jaw, AC/DC amps with inrush
- Low-pass filter for accurate readings on VFD outputs
- Two temperature inputs for delta-T
- High safety rating: CAT IV 600 V / CAT III 1000 V
Keep in mind
- About 100 h battery life on a 9 V, less with wireless and backlight
- Heavy at about 480 g and long at 301 mm
The SC680 also reads DC microamps (1,000 uA) and capacitance to 10 mF, so for many techs it can replace a separate multimeter. See our SC680 review and the Klein vs Fieldpiece comparison.
Best for: Residential techs who want a small HVAC clamp with capacitance and temperature.
- 400 A AC current, True-RMS
- AC/DC voltage; capacitance; resistance to 40 Mohm
- Temperature in F and C
- 4000-count display
- 9 V battery, about 150 h; auto power off about 30 min
Why it stands out
- Capacitance and temperature in a compact clamp
- Light at about 265 g
- Lower price than Fluke or the Fieldpiece SC480/SC680
Keep in mind
- AC amps only; no DC current listed
Best for: A simple, durable amp clamp to pair with an HVAC multimeter like the Fluke 116.
- AC current 400.0 A, True-RMS
- AC/DC voltage 600 V
- Resistance to 4000 ohm; continuity
- No DC amps, capacitance, frequency or temperature
- CAT III 600 V / CAT IV 300 V; max conductor 30 mm (600 MCM)
Why it stands out
- True-RMS AC amps from a trusted brand
- Light at 265 g
- Simple dial, few modes to fumble
Keep in mind
- No capacitance, temperature or microamps, so it cannot stand alone for HVAC diagnostics
- Resistance only to 4000 ohm
- No DC amps
The 323 does one thing well. If you want a clamp that can stand in for a multimeter, look at the DL389B instead.
Best for: Techs who want a compact Fluke clamp with DC amps, temperature and capacitance.
- AC and DC current 400.0 A; True-RMS
- AC/DC voltage 600 V
- Capacitance to 1000 uF; frequency 5 to 500 Hz
- Type K temperature 14 to 752 F, thermocouple included
- CAT III 600 V / CAT IV 300 V; max conductor 30 mm (600 MCM)
Why it stands out
- Reads DC amps, which the 323 does not
- Adds capacitance, frequency and temperature
- Compact and light at 283 g
Keep in mind
- No microamp range listed for flame sensors
- Capacitance tops at 1000 uF
- Premium priced
Best for: Commercial techs who want power measurement, phase rotation and app logging.
- 600 A wireless clamp with Job Link app connection
- True RMS with a low-pass filter for VFD and non-linear loads
- Power (watts), voltage, current, capacitance, frequency and phase rotation
- Inrush current and two-lead 3-phase testing
- DC microamps and non-contact voltage per Fieldpiece
Why it stands out
- Power and phase rotation in one clamp
- Wireless logging to the Job Link app
Keep in mind
- Premium price tier
- More meter than most residential service calls need
Clamp meters that left this guide
The Klein CL800 is no longer listed in Klein’s clamp meter catalog. Klein’s current model in that slot is the CL810, a 600 A AC/DC True-RMS clamp with LoZ, inrush, DC microamps, 6,000 uF capacitance, temperature, non-contact voltage and a 1.4 in jaw. Read our CL800 page for the details. The Southwire 21550T is another option to check.
Still deciding?
Best all-in-one for residential: UEi DL389B Dual Display True-RMS HVAC Clamp Meter with Temperature. Amps, flame-sensor microamps, 4,000 uF capacitance and temperature in one clamp.
Frequently asked questions
Can a clamp meter replace my multimeter?
Many HVAC clamp meters can. Models with test-lead microamps, capacitance and temperature, such as the UEi DL389B (2000 uA, 4000 uF, Type K) or Fieldpiece SC480, cover the flame sensor, capacitor and temperature tests. A basic clamp like the Fluke 323 cannot.
Do I need DC amps?
For most residential split systems, no. DC amps matter for inverter equipment diagnostics, DC fan motors and solar or battery work. The Fluke 323 and UEi DL389B are AC-only on the jaw; the Fluke 325, Fieldpiece SC680, Klein CL810 and UEi DL429B read DC amps.
What is inrush and why does it matter?
Inrush mode captures the peak starting current of a motor or compressor in the first fraction of a second. Comparing it to the nameplate LRA helps diagnose hard-start problems and size a hard-start kit. The Fieldpiece SC680 and UEi DL429B list inrush capture.
Is a wireless clamp meter worth it?
If you document jobs or watch amps while standing at the thermostat, yes. The Fieldpiece SC680 and SC480 send readings to the Job Link app, and the UEi DL429B uses UEi's app. Wireless shortens battery life (the SC680 lists about 100 h without wireless or backlight).
What jaw size do I need?
Residential conductors fit almost any clamp. For commercial rooftop units and larger feeders a 1.4 in jaw (Klein CL810) or a 600 MCM rating (Fluke 323/325, 30 mm max wire diameter) is more practical.
Keep reading
Sources
Specifications and product details were checked against these sources:
- ueitest.com / dual display hvac clamp meter
- fieldpiece.com / sc680 wireless power clamp meter
- fieldpiece.com / sc260 compact clamp meter with true rms
- fieldpiece.com / clamp meters
- supplyhouse.com / Fieldpiece SC260 SC260 Compact Clamp Met
- fluke.com / fluke 323
- fluke.com / fluke 325
- fieldpiece.com / sc480 wireless power clamp meter
