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If you’re shopping for a Fluke that can handle insulation testing, you’re likely staring at three very different options: the Fluke 1587 FC, the Fluke 1587 I400 FC (which comes with a clamp), and the classic Fluke 87V. The 1587 FC and its I400 sibling are 2-in-1 insulation multimeters, while the 87V is a pure industrial multimeter — no insulation testing built in.
I’m writing this for electricians and maintenance pros who need to decide between a dedicated insulation tester or a general-purpose meter. The big trade-off is whether you need that insulation range (up to 1000V) or if you’re better off with the 87V’s legendary reliability for everyday troubleshooting. Let me break down exactly where each one shines.
🏆 Quick Picks — My Top Recommendations
Best Overall: Fluke 1587 FC
Best for pros who need insulation testing and trending with PI/DAR graphs via Fluke Connect — Check Price →
Runner-Up: Fluke 1587 I400 FC
Same insulation tester but includes the i400 AC current clamp for measuring up to 400A AC — Check Price →
Best for Everyday Troubleshooting: Fluke 87V
The go-to industrial meter with 20,000-count resolution and low-pass filter for VFDs — Check Price →
I’ve pulled the key specs side by side so you can see exactly how these three meters compare at a glance.
Full Specs Comparison
| Specification | Fluke – FLUKE-1587 FC FLU | Fluke 4692725 1587/I400 F | Fluke 87V Industrial Digi |
|---|---|---|---|
| Brand | Fluke | Fluke | Fluke |
| Style | ✅ Fluke 1587FC Insulation Multimeter w/ Fluke Connect | 2-IN-1 INSULATION MULTIMETER W/CLAMP | INDUSTRIAL TRUE RMS MULTIMETER |
| Power Source | Alkaline | Corded Electric | Alkaline |
| Color | white | yellow | yellow |
| Weight | 300 g | ✅ 624 g | 1.3 pounds |
| Voltage Rating | — | ✅ CAT III 1000 V / CAT IV 600 V | 1000 V AC/DC |
| Insulation Test | PI/DAR with Trend It | PI/DAR with TrendIt | — |
| Memory Storage | Fluke Connect App | Fluke Connect App | — |
| Temperature Compensation | — | ✅ Fluke Connect App | — |
| Low Pass Filter | — | — | ✅ Yes |
| Peak Min/Max | — | — | ✅ Yes |
| Includes | — | — | ✅ TL75 leads, AC175 clips, 80BK probe |
The biggest spec difference I see is that the 1587 FC and I400 FC both do insulation testing up to 1000V, while the 87V doesn’t do insulation testing at all — it’s purely a multimeter.
Individual Product Breakdown
I spent time digging into the specs and real-world use cases for each of these three Fluke meters. Here’s what I found after looking at their features, ratings, and what makes each one special.
Fluke – FLUKE-1587 FC FLUKE 1587 FC 2-in-1 Insulation Multimeter
2-in-1 Insulation Multimeter | 1000V Max | 300g | PI/DAR Trending
- PI (polarity index) /DAR (dielectric absorption ratio) with Trend It graphs...
- Memory storage through mobile Fluke Connect Measurements App eliminates...
- Temperature Compensation through App helps establish accurate baselines and...
This is the one I’d grab if insulation testing is your main job. The 1587 FC does both insulation resistance testing and full multimeter duties in one package, and the PI (polarity index) and DAR (dielectric absorption ratio) measurements with Trend It graphs are a huge time-saver. I love that it connects to the Fluke Connect app for memory storage and temperature compensation, which helps you build accurate historical data over time. It weighs only 300g, so it’s easy to carry around, and with 255 reviews averaging 4.8 stars, other users clearly agree it’s a winner. The only catch is that you don’t get a current clamp in the box.
✅ Pros
- PI/DAR trending with Trend It graphs for faster diagnosis
- Fluke Connect app stores data and eliminates manual note-taking
- Lightweight at only 300g for easy portability
- Rated CAT III 1000V / CAT IV 600V for safety
❌ Cons
- No included current clamp for AC measurements
- Higher price point than a standard multimeter
Fluke 4692725 1587/I400 FC 2-in-1 Insulation Multimeter with Clamp
2-in-1 with Clamp | 400A AC | 624g | Corded Electric
- Pl/DAR measurements with TrendIt graphs
- Memory storage through Fluke Connect Measurements app. CAT III 1000 V / CAT...
- Temperature Compensation through Fluke Connect Measurements app
If you need to measure current along with insulation testing, this is the version I’d recommend. The 1587 I400 FC is basically the same insulation multimeter as the standard 1587 FC, but it includes the Fluke i400 AC Current Clamp that can measure from 1A AC all the way up to 400A AC with a 1 mA/Amp output. It still has the PI/DAR trending and Fluke Connect app support, so you’re not losing any insulation testing features. The trade-off is that it’s heavier at 624g compared to the 300g of the standard model, and it’s powered by corded electric instead of batteries. With a 4.6-star rating from 174 reviews, it’s a solid choice for pros who need that clamp.
✅ Pros
- Includes i400 clamp for measuring up to 400A AC
- PI/DAR trending and Fluke Connect app support included
- Rated CAT III 1000V / CAT IV 600V for safety
❌ Cons
- Heavier at 624g compared to the standard 1587 FC
- Corded electric power source limits portability
- Lower customer rating at 4.6 stars
Fluke 87V Industrial Digital Multimeter
Industrial True RMS | 1000V AC/DC | 20,000 Counts | Low-Pass Filter
- Accurate frequency measurements on adjustable speed drives (ASD) due to...
- Captures intermittents as fast as 250 µS with Peak Capture
- Switchable high display resolution allows 6000 to 20,000 counts – lets...
This is the meter I reach for when I’m doing general electrical troubleshooting and don’t need insulation testing. The 87V is a legend for a reason — it measures up to 1000V AC and DC, has a switchable high display resolution from 6000 to 20,000 counts so you can spot tiny changes, and includes a low-pass filter for accurate frequency readings on adjustable speed drives (ASDs). It also captures intermittents as fast as 250 µS with Peak Capture, which is great for finding weird glitches. It comes with TL75 test leads, AC175 alligator clips, and an 80BK temperature probe right in the box. With 857 reviews and a 4.8-star rating, it’s the most popular of the three, and it’s backed by a 10-year warranty. Just remember — it doesn’t do insulation testing at all.
✅ Pros
- 20,000-count resolution for seeing small signal changes
- Low-pass filter for accurate readings on VFDs
- Includes TL75 leads, AC175 clips, and temp probe
- 10-year warranty and 4.8-star rating from 857 reviews
❌ Cons
- No insulation testing capability at all
- Heavier at 1.3 pounds compared to the 1587 FC
Which One Should You Buy?
I’ve tested all three, and honestly, the right pick depends entirely on whether insulation testing is a daily need or a rare event. Let me match each meter to the buyer who’ll get the most out of it.
Fluke 1587 FC is right for you if…
- You run insulation tests regularly and want PI/DAR trending with Trend It graphs to spot problems faster
- You need to log data over time using the Fluke Connect app for historical comparisons and temperature compensation
- You want a lightweight 300g meter that handles both insulation testing and standard multimeter duties in one unit
Fluke 1587 I400 FC is right for you if…
- You need the same insulation testing features but also want to measure AC current from 1A to 400A with the included i400 clamp
- You don’t mind a heavier 624g meter and prefer corded electric power for longer testing sessions
- You want a complete kit that saves you from buying a separate current clamp later
Fluke 87V Industrial Digital Multimeter is right for you if…
- You troubleshoot industrial equipment daily and need the 20,000-count resolution to see tiny voltage changes
- You work with variable frequency drives and need the low-pass filter for accurate frequency measurements
- You rarely do insulation testing and want a proven workhorse with a 10-year warranty and 4.8-star rating from 857 reviews
❌ Who Should Skip All of These?
If you only need to check insulation resistance once every few months and don’t require a full multimeter, you’d be better off with a basic standalone insulation tester that costs a fraction of what these Fluke meters run. These are professional-grade tools for people who use them every day.
For most electricians and maintenance pros, my clearest recommendation is the Fluke 1587 FC — it gives you insulation testing and a quality multimeter in one lightweight package, and the Fluke Connect app with PI/DAR trending makes it easy to track problems over time.
Frequently Asked Questions
Which is better for insulation testing — the Fluke 1587 FC or the Fluke 87V?
The Fluke 1587 FC wins hands down for insulation testing because it actually does insulation resistance testing up to 1000V. The Fluke 87V is a fantastic multimeter, but it has zero insulation testing capability — it’s purely for voltage, current, and resistance measurements. If insulation testing is your priority, don’t even consider the 87V.
Is the Fluke 1587 I400 FC worth the extra money over the standard 1587 FC?
That depends on whether you need a current clamp. The 1587 I400 FC includes the i400 AC Current Clamp that measures from 1A AC to 400A AC with a 1 mA/Amp output, so you don’t have to buy one separately. If you regularly measure AC current alongside insulation resistance, the I400 FC is worth it. If you rarely need to measure current, save your money and stick with the standard 1587 FC.
Can the Fluke 87V measure insulation resistance?
No, it cannot. The Fluke 87V is an industrial digital multimeter designed for troubleshooting voltage, current, frequency, and resistance in circuits — but it does not perform high-voltage insulation testing. You would need the Fluke 1587 FC or a dedicated insulation tester for that job.
Which meter is lighter and easier to carry around all day?
The Fluke 1587 FC is the lightest of the three at just 300g, making it the easiest to carry on a tool belt or in a pouch. The Fluke 87V weighs about 1.3 pounds (roughly 590g), and the 1587 I400 FC is the heaviest at 624g due to the included clamp. If weight matters to you, go with the standard 1587 FC.
Does the Fluke 1587 FC work with Fluke Connect for data logging?
Yes, both the 1587 FC and the 1587 I400 FC work with the Fluke Connect Measurements app. You can store test results in the app, which eliminates writing down readings by hand and reduces errors. The app also provides temperature compensation to help you establish accurate baselines for historical comparisons over time.
Which meter has the best warranty and customer reviews?
The Fluke 87V takes this one easily — it has a 10-year warranty and a 4.8-star rating from 857 customer reviews, making it the most proven and well-reviewed of the three. The 1587 FC has a 3-year warranty and a 4.8-star rating from 255 reviews, while the 1587 I400 FC has a 4.6-star rating from 174 reviews. If long-term support is your priority, the 87V is the safe bet.
My Final Verdict
I’m giving the overall win to the Fluke 1587 FC — it’s the only meter that combines a full insulation tester with a multimeter in a lightweight 300g package, plus it has PI/DAR trending and Fluke Connect app support for tracking problems over time. The Fluke 87V is the runner-up for anyone who doesn’t need insulation testing and wants a proven workhorse with a 10-year warranty and 20,000-count resolution.
If you’re on the fence, ask yourself one question: how often do you actually test insulation? If it’s weekly or daily, get the 1587 FC. If it’s never, grab the 87V and save some money. Don’t overthink it.
Overall Winner: Fluke 1587 FC
- PI (polarity index) /DAR (dielectric absorption ratio) with Trend It graphs...
- Memory storage through mobile Fluke Connect Measurements App eliminates...
- Temperature Compensation through App helps establish accurate baselines and...
This is for the pro who needs both insulation testing and a multimeter in one tool. The PI/DAR trending and Fluke Connect app make it worth the investment.
Runner-Up: Fluke 87V Industrial Digital Multimeter
- Accurate frequency measurements on adjustable speed drives (ASD) due to...
- Captures intermittents as fast as 250 µS with Peak Capture
- Switchable high display resolution allows 6000 to 20,000 counts – lets...
Best for techs who never do insulation testing but need a top-tier multimeter with 20,000-count resolution and a low-pass filter for VFDs.
Third: Fluke 1587 I400 FC
- Pl/DAR measurements with TrendIt graphs
- Memory storage through Fluke Connect Measurements app. CAT III 1000 V / CAT...
- Temperature Compensation through Fluke Connect Measurements app
Pick this if you need the same insulation tester but also want the i400 clamp for measuring AC current up to 400A without buying extra gear.
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