Do you know what your Current meter is rated for?

Ask any HVAC service Tech out there what their 5 most used tools are, and I guarantee 95% will have a multimeter in the top 5. A good portion of this trade requires that you know what you are doing when it comes to electricity. Not only for being able to perform your day to day tasks but for safety as well. Even if you don’t work in the service portion of this trade, it is important that you understand how to use a meter correctly to ensure that you are safely performing any functions that could put you into harm’s way. All meters are not created equal, and today we are going to take a look at some of the ratings and features that can help you determine which meter is right for you.

There are a ton of options available, and I believe that meters are something you should take seriously when looking to make a purchase. This is not a tool you want to cheap out on, you are selecting a tool that you are trusting your life with. This is a tool that you will be placing into direct contact with high voltage/high current electrical connections. Not all meters are created equal when it comes to safety, and the real issue for multimeter protection is not just the maximum steady voltage range, but a combination of both steady-state and transient over voltage capabilities.

Transient voltage, or voltage spikes, are an unavoidable hazard. Lightening strikes, motors, capacitors, and variable frequency drives are all culprits that have the potential to generate these high voltage spikes onto the electrical system. The voltage rating of the meter alone does not tell you how well the meter was designed in order to handle these quick high voltage spikes. It is important to understand the measurement category ratings which are often abbreviated as CAT I, CAT II, CATIII, etc. These categories are divided into the divisions of power systems based on the fact that a high voltage power spike, such as a lightening strike, is going to be mitigated as it travels through the electrical system.

For example, lightning strikes a power pole causing an extremely high voltage spike on utility power to the building. These conductors are designed to carry and sustain high voltage and current which leads to higher transient overvoltage exposure in these areas. As the power passes into the building, it is dispersed through distribution panels, step down transformers, and then onto receptacles, appliances, and other electronics. The high energy transient voltage of the lightning strike will be dampened as it passes through the electrical system into each of the different categories.

In the example of the lightning strike, if a technician was using a CAT II meter in a CAT III location this can lead to the possibility of creating an arc flash scenario. If the meter leads are in contact between 2 terminals during a transient voltage spike with a peak impulse higher than the rating of the meter being used hits, there is the potential to cause an arc between the meter leads internal to the meter resulting in a direct short. The meter leads are in contact with the source, allowing the current to flow through to the failure point allowing the short. As the tech is startled by the loud pop in the meter, the Tech begins to remove the leads from the live electrical source. Electrical energy is now drawn towards the meter tips with the possibility of arcing through the air to the leads. If the electrical arcs being generated meet, the potential for an arc blast is created. The danger of an arc blast is the heat generated possibly reaching 10,000 degrees F. These extreme temperatures can cause burns to the airway extremely quickly, causing swelling and suffocation. This is why proper PPE such as insulted gloves, eyewear, and face shields should be worn when exposed to these hazards.

In addition to transient voltage protection, overload protection should also be high on the priority list. Meters are often used to take live electrical readings, but what about checking mA or resistance? If the selector is left in the resistance position and the meter leads are placed across a voltage source, we are allowing a short circuit through the meter. This is also true if you were to leave your meter leads in the amps terminals and place the leads to a voltage source also resulting in a short circuit. Make sure that you are using a meter with overload protection, as well as being mindful of the meter settings before touching your leads to live electrical components.

You should always look for an electrical multimeter that has been independently tested to ensure that the ratings placed on the meter have actually been verified and meet the current standards. We see it more and more with no name brand units trying to confuse consumers by using terminology such as “designed to meet” or just outright claiming a certain certification without any verification or third-party testing to ensure that it actually meets that standard being claimed. Look for meters that have been tested and meet the standards of labs such as UL, CSA, and TUV.

Check out the Full video Comparing my favorite HVAC Meters Under $400

Most Affordable Meter

If you are looking to spend the absolute bare minimum in order to get out and start working making money, The Amprobe 510 is probably the meter for you. This Meter was designed towards residential use with some light commercial use and is a UL rated CAT III 600v AC/DC Multimeter. This tool features a large backlit LCD display, Auto shut off feature to conserve battery, non-contact voltage detector, resistance to 40 megohms, capacitance to 100 microfarads, frequency to 10 megahertz (MHz), and microcurrent to 4,000 microamps.

Personally have had some issues with Amprobe meters I’ve used in the past. They do not seem to be as durable as some of the other options available, especially when used during harsh weather conditions exposing it to moisture. A few other cons of this meter are that the non-contact voltage feature is unreliable and inaccurate, and This meter is not a true RMS meter. If you can live with those deficiencies, and keep it out of the weather, this affordable option should serve you well.

If you are willing to spend a Few Bucks more, Check out the Amprobe 530. This meter has a few additional features over the 510 that were personally favorable to me. This meter is a TRU RMS (learn more about True RMS Here from Fluke), includes a thermocouple with the ability to take temperature readings. Check out the video above to see it in action. I have run into some issues with it reading a couple of degrees off, so if utmost accuracy is extremely important to you, that is something that you should keep in mind.

Best HVAC Meter Under $100

Just getting started and looking to keep costs down? Look no further than the 323. The Fluke 323 clamp meter is designed to perform in the toughest environments and provide noise-free, reliable results you can trust to confidently diagnose any problems. This model is ideally suited for current measurements up to 400 A in tight cable compartments. This is a True RMS device packed with features in a small easy to carry package and is often regarded as one of the best general troubleshooting tools for commercial and residential HVAC technicians. CAT IV 300V/CAT III 600 V safety rating ensures that you can use this meter in a multitude of environments, Resistance measurement up to 4 kΩ with continuity detection, and the ability to take voltage readings in both AC and DC signals. Looking for more information on How to get into the HVAC trade? Check out my blog post!

Best HVAC Multimeter under $200

If you are looking for a really solid Multimeter designed with the HVAC professional in mind its hard to ignore the FLUKE 116. The 116 is a CAT III 600v meter with the ability to take temperature as well as microamp readings. The 116 is a true RMS meter which is a must for today’s modern equipment. A true RMS multimeter can measure both sinusoidal and nonsinusoidal waves with a higher degree of accuracy. A standard meter can measure nonsinusoidal waves, but with much lower accuracy (up to 40% low or 10% higher) The 116 allows you take a variety of measurements, resistance, continuity, frequency, capacitance, voltage both AC and DC, temperature and microamps. This unit features a large white LED backlight which allows you to work in any environment. Fluke is known for quality instruments and the 116 is one of the meters I personally carry myself.

You are often able to find a combo deal for both the 116 and the 323 providing you with the best bang for the buck in my opinion. The features of the 116 are great, but everyone needs to have a clamp meter. Check current Amazon pricing for the 116/323 combo HERE

Best HVAC Multimeter under $300

One of the most feature-packed multimeters is the 902fc. This tool is again designed with the HVAC field Tech in mind. CAT III 600v / CAT IV 300V ratings. Ability to take microamp readings for flame sensors, AC and DC True RMS voltage readings, capacitance, Temperature, as well as resistance readings up to 60 Kilohms.

The 902 FC is a wireless tool that can transmit measurements and readings to a smartphone or tablet which can be uploaded to your preferred storage for detailed analysis at a later time if necessary. This allows great versatility for the filed technician. An added benefit of the wireless feature is the ability to reduce the Technicians’ exposure to high voltage/current components. Once you have the tool in place, verify that you are synced with a smart device via the app, close the panel, reenergize the equipment, and take your readings from a safe distance away. Our technicians use this feature daily which reduces the frequency that they are required to wear NFP 70e PPE.

This multimeter has earned a permanent place in my service bag and gets used daily. If you are looking to only run one meter, this one would be my recommendation. I currently run a combination of the 902fc and the 116.

Best HVAC Multimeter under $400

If you are in need of a meter that requires you to take current readings in excess of 600 amps. Take a look at the 376 FC. This meter features a CAT III 1000v / CAT IV 600V rating for ultimate protection. This meter is a true RMS clamp meter which also includes a flexible current probe for tight spaces, and the ability to record current readings up to 2500 amps. The wireless readout feature is a great tool to utilize when exposed to current levels that high.

A great feature of the Fluke 376is the ability to log readings. Logging capabilities help to troubleshoot intermittent faults that may otherwise be almost impossible to track down. Purchasing additional units will allow you to adequately monitor 3 phase power using the connect app and is a great benefit to any service tech or field engineer. These meters are proven tough in all types of harsh environments. This is not a cheap tool, but a very capable and professional device at an affordable price.

Honorable Mention

I always get a lot of flack when I don’t include Fieldpiece meters. Honestly, I’ve never run this model, but a lot of guys have, and most seem to be happy with it. A Benefit of this unit is that it includes accessories such as alligator clip meter leads, heavy-duty magnet, and a type K thermocouple. The SC440 is A True RMS Clamp Meter designed to take more accurate VAC and AAC readings on VFDs. It also features safety features such as a high-voltage LED and beeper, a continuity warning, push button non-contact voltage, a lead holder with detachable leads, and alligator probe tips for easy one-handed testing. Testing parameters include temperature, capacitance, microamps DC for flame diode tests, and everyday electrical ranges for the HVAC Tech. The SC440 clamp meter is designed for HVACR service. For me, the cost savings are not there to justify purchasing this over a Fluke meter, but that’s entirely up to you.

The SC680 also has many features that are important to HVAC Techs. You can check out my review of the Fieldpiece SC680 HERE. I had issues with my first SC680, but Fieldpiece took care of me. Check out the review to make sure yours doesn’t have similar issues.

Conclusion

A meter is arguably the most important tool you will purchase. I took a poll of 100 Techs to determine which meter manufacture they recommend, and the results can be seen below. You can clearly see that Fluke is the preferred brand among the majority of techs in the field. The most common complaint was the cost of fluke meters and that they were lacking in the included accessories, such as alligator clips, etc.

I found it interesting that multiple users complained of the quality of the UEI instruments they were using. A common complaint being that the lead terminals getting loose, causing the leads to come slightly out of the meter. When this happens, your meter does not read any voltage, giving you a false security that the circuit is dead. This exact scenario was described by 3 techs in my poll and even lead to 2 of these technicians receiving an electric shock because of it. This should serve as a reminder to always inspect your gear.

As you can see there is a lot that goes into your decision on purchasing a meter. At the end of the day, safety is number 1. Don’t use a tool that may get your hurt. There are a lot of good brands out there, but I myself, and many others prefer fluke for a reason when it comes to electrical tools. When searching for your new meter, first try and Analyze the worst-case scenario in relation to which CAT rating area you may find yourself using a meter in. Select a meter that is rated for the absolute highest category you may find yourself working in, and then determine the voltage rating for that category to fit your needs. If you ever need to replace your meter leads, ensure that you are purchasing quality leads as well! Your meter ratings are only as good as the leads you are using them with! Quality meters can be expensive, but as one of the primary tools used in the HVAC trade its worth while to buy quality. Curious to find out How much do HVAC Techs Make? Check out my article at the link!

Let me know what you carry every day. Do you have other suggestions that should be on this list? Let me know in a comment below.

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