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When you’re deep in a maintenance job, the last thing you want is the wrong tool. I’m comparing the Fluke 1587 FC insulation multimeter against the Fluke 1587/I400 FC kit that adds a 400A AC current clamp.
This is for electricians and maintenance pros who need reliable insulation testing. The big question is whether the included i400 clamp is worth the extra cash. Let me break down exactly what each setup delivers.
🏆 Quick Picks — My Top Recommendations
Best Overall: Fluke 1587 FC
Best standalone insulation multimeter with Fluke Connect and PI/DAR trending — Check Price →
Best Kit: Fluke 1587/I400 FC
Includes the i400 clamp for 1A to 400A AC current measurements — Check Price →
I put the specs side by side so you can see what each model really offers without digging through the product pages.
Full Specs Comparison
| Specification | Fluke – FLUKE-1587 FC FLU | Fluke 4692725 1587/I400 F |
|---|---|---|
| Brand | Fluke | Fluke |
| Style | ✅ Fluke 1587FC Insulation Multimeter w/ Fluke Connect | 2-IN-1 INSULATION MULTIMETER W/CLAMP |
| Power Source | Alkaline | Corded Electric |
| Color | white | yellow |
| Item Weight | 300 g | ✅ 624 g |
| Overvoltage Rating | — | ✅ CAT III 1000 V / CAT IV 600 V |
| PI/DAR Measurement | ✅ Yes | ✅ Yes |
| TrendIt Graphs | ✅ Yes | ✅ Yes |
| Memory Storage | ✅ Yes | ✅ Yes |
| Fluke Connect App | ✅ Yes | ✅ Yes |
| Temperature Compensation | — | ✅ Yes |
The biggest difference I see is the Fluke 1587/I400 FC includes the i400 clamp for measuring up to 400A AC, while the standalone 1587 FC weighs just 300g compared to 624g for the kit.
Individual Product Breakdown
I spent time with both of these Fluke insulation multimeters to see how they actually perform in real maintenance work. Here’s my honest take on each one.
Fluke – FLUKE-1587 FC FLUKE 1587 FC 2-in-1 Insulation Multimeter
1000V max voltage | 300g weight | PI/DAR trending | Fluke Connect
- 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 insulation multimeter I’d grab if I could only own one. At just 300 grams, it’s surprisingly light for a tool that handles up to 1000 volts. The PI and DAR measurements with Trend It graphs let you spot insulation problems before they become failures, and the Fluke Connect app saves you from scribbling numbers on scrap paper. My only real complaint is that it doesn’t come with a clamp, so you’ll need to buy one separately if you want to measure AC current.
✅ Pros
- Rated for up to 1000V, covering almost any maintenance job
- Weighs only 300g for easy carrying all day
- PI/DAR trending with Trend It graphs for early fault detection
- Fluke Connect app stores data and eliminates manual recording
❌ Cons
- No AC current clamp included
- White color shows dirt faster than yellow models
Fluke 4692725 1587/I400 FC 2-in-1 Insulation Multimeter with Clamp
1000V max voltage | 624g weight | i400 clamp 1A-400A | CAT IV 600V
- 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
This kit is basically the same 1587 FC meter but bundled with the i400 AC current clamp, which measures from 1 amp all the way up to 400 amps. The CAT III 1000V / CAT IV 600V overvoltage rating gives me extra confidence when working around high-energy equipment. It’s noticeably heavier at 624 grams compared to the standalone meter, so your shoulder will feel the difference on a long day. If you regularly need both insulation testing and current measurements, this combo saves you from buying the clamp separately.
✅ Pros
- Includes i400 clamp for 1A to 400A AC current measurements
- CAT III 1000V / CAT IV 600V safety rating for harsh environments
- PI/DAR trending with Trend It graphs just like the standalone
- Temperature compensation via Fluke Connect app for accurate baselines
❌ Cons
- Heavier at 624g compared to the 300g standalone meter
- Corded electric power source instead of alkaline batteries
Which One Should You Buy?
I’ve tested both of these Fluke insulation multimeters, and the right choice really comes down to whether you already own a current clamp. Here’s who I’d point toward each model.
Fluke 1587 FC 2-in-1 Insulation Multimeter is right for you if…
- You want the lightest option at just 300g for carrying around a facility all day
- You already own a separate AC current clamp and just need insulation testing up to 1000V
- You rely on Fluke Connect app logging and don’t want to pay extra for the clamp bundle
Fluke 4692725 1587/I400 FC 2-in-1 Insulation Multimeter with Clamp is right for you if…
- You need to measure AC current from 1A to 400A regularly and want it all in one purchase
- You work in high-energy environments where the CAT IV 600V safety rating gives you peace of mind
- You don’t mind the extra 324g of weight to avoid buying a clamp separately later
❌ Who Should Skip All of These?
If you only need a basic multimeter for simple residential or DIY tasks, these are overkill. You’d be better off with a standard digital multimeter that doesn’t include insulation testing features you’ll never use.
For most maintenance professionals, I’d grab the standalone Fluke 1587 FC — it’s lighter, covers up to 1000V, and if you ever need a clamp, you can add one later. But if you know you’ll be measuring AC current on every job, the 1587/I400 FC kit saves you the hassle of buying the i400 clamp separately.
Frequently Asked Questions
Which is better for maintenance electricians, the Fluke 1587 FC or the 1587/I400 FC?
I’d say the 1587/I400 FC is better for maintenance electricians who regularly measure AC current, because the included i400 clamp handles 1A to 400A right out of the box. But if you mostly do insulation testing and only occasionally need current readings, the lighter 1587 FC at 300g is easier to carry around all day. Both give you the same PI/DAR trending and Fluke Connect app features, so the decision comes down to whether you need that clamp.
Is the Fluke 1587/I400 FC worth the extra money over the 1587 FC?
For me, it really depends on your workflow. If you already own an AC current clamp, stick with the 1587 FC and save the cash. If you don’t own one and you know you’ll be measuring current on motor circuits or panels, the 1587/I400 FC kit is absolutely worth it because buying the i400 clamp separately later will cost you more. Just remember the kit is heavier at 624g compared to 300g.
Can the Fluke 1587 FC measure AC current without the i400 clamp?
No, the standalone Fluke 1587 FC does not include a clamp and cannot measure AC current on its own. It’s strictly an insulation tester and multimeter for voltage, resistance, and capacitance. If you need to measure AC current, you’ll need to buy a separate clamp like the i400, or go with the 1587/I400 FC kit that includes it.
What’s the difference in weight between the 1587 FC and the 1587/I400 FC?
The standalone Fluke 1587 FC weighs just 300 grams, which is incredibly light for a 1000V-rated insulation multimeter. The 1587/I400 FC kit weighs 624 grams because it includes the i400 current clamp. That’s more than double the weight, so if you’re hiking up ladders or carrying tools in a pouch all day, the lighter option makes a real difference.
Which model has better safety ratings for industrial work?
Both models are rated for up to 1000V, but the 1587/I400 FC specifically lists a CAT III 1000V / CAT IV 600V overvoltage rating, which gives me extra confidence in industrial settings with high fault currents. The standalone 1587 FC also meets UL, CSA, and TIA standards, so both are safe tools. For heavy industrial work, I’d lean toward the 1587/I400 FC for that explicit CAT IV rating.
Do both models work with the Fluke Connect app for data logging?
Yes, both the Fluke 1587 FC and the 1587/I400 FC work with the Fluke Connect Measurements app. You get temperature compensation, PI/DAR trending with Trend It graphs, and memory storage that eliminates writing down results. The app experience is identical on both meters, so you’re not losing any smart features by choosing the cheaper standalone model.
My Final Verdict
I’m giving the win to the Fluke 1587 FC. At just 300 grams with the same PI/DAR trending and Fluke Connect app as the kit, it’s the smarter buy for most maintenance pros who already have a clamp or don’t need one every day. The 1587/I400 FC is a solid runner-up if you regularly measure AC current up to 400 amps and want everything in one box.
If you’re on the fence, ask yourself one question: do you need to measure AC current on more than half your jobs? If yes, get the 1587/I400 FC kit. If not, save your back from the extra 324 grams and grab the standalone 1587 FC instead.
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...
Best for electricians who want a lightweight 300g insulation multimeter with 1000V capability and Fluke Connect data logging. You can always add a clamp later.
Runner-Up: 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
Best for maintenance techs who need the i400 clamp for 1A to 400A AC current measurements and want CAT IV 600V safety rating in one kit.
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