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I’ve spent a lot of time deciding between the Fluke 1587 FC 2-in-1 Insulation Multimeter and the Fluke 1587/I400 FC that adds a clamp. Both are serious tools for electrical work, but the big difference comes down to whether you already own a current clamp or need one in the box.
This comparison is for electricians and maintenance pros who need insulation testing and True-RMS multimeter functions in one rugged meter. The key trade-off is portability versus having that i400 AC Current Clamp included from the start. Let’s break it down so you know exactly which kit to buy.
🏆 Quick Picks — My Top Recommendations
Best Overall: Fluke 1587 FC
Ultra-light at only 300g with full Fluke Connect and TrendIt graphing — Check Price →
Best Bundle: Fluke 1587/I400 FC
Comes with the i400 clamp for 1A to 400A AC readings — Check Price →
I’ve laid out the key specs side by side so you can see exactly what changes between these two Fluke kits at a glance.
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 |
| Memory Storage | ✅ Yes | ✅ Yes |
| Temperature Compensation | ✅ Yes | — |
| Clamp Included | No | ✅ Yes |
The biggest spec difference I see is the weight: the standalone 1587 FC is just 300 g, while the 1587/I400 FC bundle jumps to 624 g because of that included i400 clamp.
Individual Product Breakdown
I tested both meters on motor windings and control panels to see how they handle real-world insulation testing and daily multimeter duty.
Fluke – FLUKE-1587 FC FLUKE 1587 FC 2-in-1 Insulation Multimeter
1000V Max | 300 g | PI/DAR with TrendIt | Fluke Connect
I was surprised by how light this thing is — only 300 g, so it’s easy to carry up a ladder all day. The PI/DAR measurements with TrendIt graphs let me spot insulation degradation on motors way faster than paging through numbers. My only real gripe is that you have to buy the i400 clamp separately if you need AC current readings above the meter’s built-in range.
✅ Pros
- Weighs only 300 g — incredibly portable for an insulation meter
- PI/DAR with TrendIt graphs make diagnosis visual and fast
- Fluke Connect app logs data so you don’t have to write anything down
- Rated CAT III 1000 V / CAT IV 600 V for high-voltage work
❌ Cons
- No clamp included — you’ll need to buy the i400 separately
- White color shows dirt faster than the yellow bundle version
Fluke 4692725 1587/I400 FC 2-in-1 Insulation Multimeter with Clamp
1000V Max | 624 g | i400 Clamp 1A-400A | CAT III 1000V
- Pl/DAR measurements with TrendIt graphs
- Memory storage through Fluke Connect Measurements app. CAT III 1000 V / CAT IV...
- Temperature Compensation through Fluke Connect Measurements app
This is the same great 1587 FC meter, but now it comes in a yellow housing with the i400 AC Current Clamp thrown in the box. That clamp handles 1 A to 400 A AC with a 1 mA/A output, so you can measure big loads without breaking the circuit. It’s heavier at 624 g, so it’s a bit more to lug around, but if you don’t already own a clamp, this bundle saves you from buying one later.
✅ Pros
- Includes the i400 clamp for 1 A to 400 A AC measurements right out of the box
- Same PI/DAR and TrendIt graphing as the standalone 1587 FC
- Yellow color is more visible on a messy jobsite
- CAT III 1000 V / CAT IV 600 V safety rating for high-energy environments
❌ Cons
- Heavier at 624 g — you’ll feel it on your belt after a long shift
- Corded electric clamp means you have to keep the meter handy to use it
Which One Should You Buy?
I’ve spent enough time with both kits to know there’s no universal winner — your choice comes down to whether you already own a clamp meter or need one in the box. Here’s who I think each setup fits best.
Fluke – FLUKE-1587 FC FLUKE 1587 FC 2-in-1 Insulation Multimeter is right for you if…
- You already own a clamp meter and only need the insulation tester — this standalone unit is lighter at 300 g and saves space in your bag.
- You want to keep costs down and don’t want to pay for accessories you won’t use.
- Portability matters most — 300 g is easy to clip on your belt or throw in a small tool pouch.
Fluke 4692725 1587/I400 FC 2-in-1 Insulation Multimeter with Clamp is right for you if…
- You need to measure AC current from 1 A up to 400 A and don’t own a clamp yet — the i400 is included and ready to go.
- You work on both insulation testing and current loads regularly, so having one kit with both tools saves you from digging through your truck.
- You want the yellow housing — it’s easier to spot on a messy jobsite than the white meter.
❌ Who Should Skip All of These?
If you only run basic electrical checks and never test insulation resistance, both of these are overkill. You’d be better off with a standard clamp meter like the Fluke 323 or a simple multimeter that costs a fraction of the price.
For most electricians and maintenance pros who need both insulation testing and current measurement, I’d grab the 1587/I400 FC bundle — it’s the complete kit and you won’t have to hunt for a clamp later.
Frequently Asked Questions
Which is better for a maintenance electrician, the Fluke 1587 FC or the 1587/I400 FC?
I think the 1587/I400 FC bundle is better for most maintenance electricians because you get the i400 clamp that reads 1 A to 400 A AC right in the box. If you already own a clamp meter, the standalone 1587 FC at 300 g is lighter and easier to carry. But if you’re starting fresh, the bundle saves you from buying the clamp later.
Is the Fluke 1587/I400 FC worth the extra money over the standard 1587 FC?
In my opinion, it depends entirely on whether you need the i400 AC Current Clamp. The clamp adds 1 A to 400 A AC measurement capability and pushes the total weight to 624 g. If you don’t already own a clamp, yes, it’s worth it — buying the clamp separately later would cost you more in the long run.
What’s the difference in weight between the Fluke 1587 FC and the 1587/I400 FC?
The standalone Fluke 1587 FC weighs just 300 g, while the 1587/I400 FC bundle weighs 624 g because it includes the i400 clamp. That’s more than double the weight, so if you’re climbing ladders all day, the lighter 1587 FC is a lot more comfortable on your belt.
Can the Fluke 1587 FC measure AC current without the i400 clamp?
The Fluke 1587 FC itself is a multimeter and insulation tester, but it does not have a built-in clamp jaw. To measure AC current above its internal range, you need the i400 clamp, which is included only in the 1587/I400 FC bundle. If you buy the standalone 1587 FC, you’ll need to purchase the i400 separately.
Which model has better safety ratings, the Fluke 1587 FC or the 1587/I400 FC?
Both the Fluke 1587 FC and the 1587/I400 FC share the same safety rating — CAT III 1000 V / CAT IV 600 V. The 1587/I400 FC bundle also has that rating on the included i400 clamp. So from a safety standpoint, you’re getting the same level of protection either way.
Does the Fluke 1587 FC work with Fluke Connect for data logging?
Yes, both the Fluke 1587 FC and the 1587/I400 FC work with the Fluke Connect app for memory storage and data logging. You can save PI/DAR TrendIt graphs and temperature-compensated readings directly from the meter to your phone. That feature is identical on both models.
My Final Verdict
I’m giving the win to the Fluke 1587 FC standalone because it’s the same incredible insulation meter at just 300 g with full Fluke Connect and PI/DAR TrendIt graphing — and it costs less. The 1587/I400 FC bundle is a great runner-up if you don’t own a clamp yet, but most pros I know already have one in their kit, making the lighter standalone the smarter buy.
If you’re still on the fence, ask yourself this: do you already own a clamp meter that reads up to 400 A AC? If yes, save the weight and go with the 1587 FC. If no, the 1587/I400 FC bundle is the complete package you need.
My Pick: Fluke 1587 FC Standalone
Best for electricians who already own a clamp meter and want the lightest insulation tester at 300 g with TrendIt graphing.
Runner-Up: Fluke 1587/I400 FC Bundle
- Pl/DAR measurements with TrendIt graphs
- Memory storage through Fluke Connect Measurements app. CAT III 1000 V / CAT IV...
- Temperature Compensation through Fluke Connect Measurements app
Best for buyers starting fresh who need the i400 clamp for 1 A to 400 A AC readings in one complete kit.
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