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Red handheld insulation tester with LCD display and test leads

TENMARS ELECTRONICS

TENMARS ELECTRONICS YF-509 Insulation Tester 250V/500V/1000V 0.1MO to 2000MO electrician tool

SKU CH-BCXP-5VCNY MPN YF-509

Tests insulation at 250V, 500V and 1000V up to 2000MO, plus AC/DC voltage and continuity

  • Labor warranty1 Year
  • Product typeTest Equipment
  • Color and finishRed
  • Number of items1 pack
  • Sold asBox
  • Parts warranty3 Years
  • Tests insulation at three voltages up to 2000MO
  • Measures AC voltage to 750V and DC to 1000V
  • Continuity check with audible tone below 80O
  • Data hold and max capture freeze key readings
  • Compact 160x100x52mm body weighs about 480g

Insulation resistance ranges

The TENMARS YF-509 is a handheld insulation tester that applies three selectable test voltages of 250V, 500V and 1000V. It measures insulation resistance manually across ranges of 0.1MO to 200MO on the lower voltages and 1MO to 2000MO at 1000V. The unit also reads AC voltage up to 750V and DC voltage up to 1000V, and includes a continuity test with audible indication below 80O. A 3-1/2 digit LCD shows readings up to 2000 counts with data hold and maximum value capture.

Who this suits and who it does not

Electricians and maintenance technicians who need to verify cable, motor or transformer insulation at standard test voltages will find the required ranges and the continuity function in one instrument. Buyers who require automatic ranging, data logging or computer connectivity will not find those features here. The tester also does not offer a dedicated low-resistance ohms range for precise contact or bond measurements.

Deciding specification

The maximum insulation test voltage of 1000V with a 2000MO upper range determines whether the instrument meets the voltage class and resistance ceiling required for the intended installation standard.

How it compares

Measured against everything we stock in Electrical Trade Tools & Kits, at today’s prices. Recalculated every night.

Price $137.99
Pricier than about 65% of the 5,006 comparable items (median $95.99).

Specifications

Product
Brand nameTENMARS
Model nameYF-509
Product typeTest Equipment
Color and finishRed
In the box
Number of items1 pack

Questions about this item

What test leads are needed to use the YF-509 for insulation resistance measurement?

The tester requires standard insulated test leads rated for at least 1000 V DC to safely apply the 250 V, 500 V and 1000 V test voltages.

Can the YF-509 verify continuity on circuits that also contain older 250 V-rated components?

Yes, the continuity test uses an open-circuit voltage of 3.3 V max and a test current of 0.4 mA max, well below 250 V component ratings.

How do I confirm the YF-509 is giving correct insulation readings after connecting the leads?

Select the 250 V range, short the leads together; the display should show 0.1 MΩ or lower, and the continuity beeper will sound if resistance is below 80 Ω.

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