Fluke 1662 vs 1663 (2026): Which Installation Tester Should You Buy?

Why you should trust this comparison

I built this comparison from Fluke’s published specifications, the documented feature lists for the 1660 series, and the verified Amazon product snippets for each tester rather than from any bench test of my own. I have not put a meter on either unit, so I will not pretend to have measured loop impedance or RCD trip times in a lab. Where a number is well documented by the manufacturer I say so plainly, and where the public spec sheets are vague I tell you that instead of inventing a figure.

The reason this approach works for the 1662 and 1663 is that they are sister models in one family. Fluke positions them as multifunction installation testers aimed at the same electrician, with the 1663 adding capability on top of the shared 1662 base. That makes the meaningful differences narrow and well described in the manufacturer literature, so an honest spec led comparison gives you a reliable buying answer without me overstating what I personally verified.

How we compared them

My first criterion was core measurement coverage: the continuity, insulation resistance, loop and line impedance and RCD functions that an installation tester lives or dies on. Both models clearly handle the everyday certification suite, so I focused on where the 1663 extends that suite and whether that extension matters to the typical buyer. The Amazon snippets confirm the 1663 lists continuity at L-N and N-PE inputs and earth resistance, while the 1662 emphasises voltage and frequency measurement and the wiring polarity check.

My second criterion was the practical fit: who actually needs the extra functions, what is shared, and what each model’s real limitation is. I weighed the value of paying for Type B RCD testing and earth resistance against the simpler, lower cost 1662 for someone doing mostly domestic and light commercial work. I deliberately avoided ranking them on price, since that moves around, and instead ranked them on capability per use case.

How they compare at a glance

Fluke 1662

The Fluke 1662 is a multifunction installation tester aimed squarely at the electrician who certifies domestic and light commercial work day in and day out. The Amazon listing describes it as the multifunction installation tester with memory in the Schuko variant, and Fluke’s feature set covers the measurements you need for an installation certificate: continuity, insulation resistance, loop and line impedance, RCD testing, plus voltage and frequency. Fluke also highlights a wiring polarity checker that it says detects broken neutral wires, which is a genuinely useful safety check during commissioning.

This is the model I would point most buyers toward because it concentrates spend on the functions that get used on nearly every job. The onboard memory means you can log results rather than scribbling them, which speeds up paperwork back at the van or office. If your work rarely strays beyond standard AC RCDs and conventional circuits, the 1662 gives you the Fluke build quality and the core test suite without paying for capability you would seldom touch.

The honest limitation is at the top end of its coverage: the 1662 is not the model Fluke positions for smooth DC sensitive Type B RCD testing, and earth resistance is not its headline function. If you take on solar, EV charging or other installations that increasingly call for Type B RCD verification, the 1662 may leave you reaching for a second instrument, which is exactly the gap the 1663 fills.

Fluke 1663

The Fluke 1663 sits above the 1662 in the same 1660 series and adds the measurements that matter on more demanding installations. Fluke documents it testing smooth DC sensitive Type B RCDs, and the product snippet lists earth resistance along with continuity at the L-N and N-PE inputs. In practice that means it carries the same everyday certification toolkit as the 1662 but extends into protective tests that a domestic only tester does not need every day, making it a better single instrument for a broader scope of work.

This is the model to choose if your jobs include the kind of equipment that drives Type B RCD requirements, such as certain EV chargers and inverters, or if you want earth resistance measurement on the same unit instead of a separate earth tester. For a contractor whose workload spans domestic, commercial and renewables, the 1663 reduces the number of instruments you have to carry and keep calibrated.

The honest limitation is that you pay for capability you may rarely use. If most of your work is standard domestic and light commercial circuits with ordinary AC RCDs, the extra Type B and earth resistance functions on the 1663 will sit idle, and the simpler 1662 would serve you just as well for the certificates you actually produce. Buying the 1663 only makes sense when those added functions map to real jobs in your schedule.

Which should you buy?

If you are a domestic installer or do mostly light commercial certification, buy the Fluke 1662. It gives you the full everyday test suite, onboard memory and Fluke reliability without paying for functions you would seldom use. It is the sensible default for the majority of electricians whose circuits use conventional AC RCDs.

If your work regularly involves Type B RCDs, EV charging, solar or other installations where smooth DC sensitive RCD testing and earth resistance are part of the job, buy the Fluke 1663. It keeps everything the 1662 does and folds in the extra protective measurements so you carry and calibrate one instrument instead of two. Match the model to the jobs in your diary rather than to the longer feature list, and the choice becomes straightforward.

Frequently asked questions

What is the main difference between the Fluke 1662 and 1663? Both share the core installation test suite, but Fluke documents the 1663 testing smooth DC sensitive Type B RCDs and lists earth resistance, capabilities the 1662 is not positioned for.

Do I need the 1663 for EV charger or solar work? Often yes, because those installations frequently call for Type B RCD verification, which the 1663 is built to cover. Confirm the requirements for your specific job and region first.

Do both testers have memory to store results? Yes. Both are part of the 1660 series memory platform, so you can log and recall test results rather than recording everything by hand.

The verdict

The Fluke 1662 and 1663 are the same well built installation tester with one meaningful split: the 1663 adds Type B RCD testing and earth resistance on top of the shared 1662 base. For most electricians doing domestic and light commercial certification, the 1662 is the smarter buy because it delivers the everyday test suite and memory without paying for functions that would rarely leave the case. Choose the 1663 only when smooth DC sensitive RCD testing and earth resistance match real jobs you take on, in which case it earns its place as a single do more instrument. Either way you are buying into a proven Fluke platform, so let your actual workload, not the spec sheet length, decide.