g/tools • Posted by u/fluke_fanatic • 5 months ago

Fluke 1507 megohmmeter vs Klein ET310 — is the price gap justified?

Tested both back to back on a 480V motor circuit last week.

Fluke 1507: $650-700 street price. Test voltages: 50, 100, 250, 500, 1000V. True RMS auto-ranging, dielectric absorption ratio and polarization index functions, Fluke's build quality and 3-year warranty.

Klein ET310: $180-200 street price. Test voltages: 500, 1000V. Does the basics reliably. Build quality is decent but not Fluke.

For one-off testing on residential/light commercial motor circuits: the Klein is genuinely adequate. For an industrial motor testing program where you're tracking insulation trends over time, the Fluke's DAR and PI functions are worth the delta — you need those metrics to catch insulation degradation before failure.

The real question is how often do you meg? If it's quarterly on a real PM program: Fluke. If it's occasional diagnostic work: Klein.

💬 3 replies

3 replies

Best New Old Controversial

u/snap_on_stan • 3 months ago

I have the Fluke 1587 (combo multimeter and megohmmeter) and it's the tool I reach for most on motor work. More expensive but one meter instead of two. Worth considering if you're already buying a new meter.

u/milwaukee_mark • 4 months ago

Good comparison. I'd add: the Fluke 1507 has a capacitance measurement function that's useful for motor capacitor testing. The Klein doesn't. For a shop that does residential motors (pool pumps, furnace blowers), that's a useful extra function in one meter.

u/voltage_vince • 3 months ago

In industrial PM programs, the PI (Polarization Index) is the number you care about for trending motor insulation. Anything below 2.0 is suspect, below 1.0 is change it now. You can't get PI from a basic megohmmeter — it needs timed readings at 1 minute and 10 minutes. That alone justifies the Fluke on industrial work.