Best 1000V Megger: 5 Insulation Testers Compared

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A 1000v megger is an insulation resistance tester that offers a 1000 V test output and reports the result in megohms. That output sits at the top of the common 250, 500 and 1000 V steps, so range and accuracy at 1000 V matter more here than in a 500 V meter. This guide helps you decide between a battery digital meter, a multimeter combination and a hand crank unit, and it shows which listing details separate the five choices. We flag every gap, including missing CAT ratings and conflicting sizes.

Quick answer

Choose the top choice if you want a 1000 V megger bundled with a True RMS multimeter, capacitance and temperature functions. Choose the second choice if you want a range of up to 2000MΩ at 1000 V and a continuous test lock. Choose the third choice for a digital display, a stated plus or minus 4 percent accuracy and a 0.1MΩ to 2GΩ range. Choose the fourth choice for a rugged build with an IP54 rating and a calibration certificate. Choose the fifth choice if you want no batteries at all. Treat every 1000 V output as hazardous and follow the manual.

What matters when choosing a 1000v megger

The measures for this keyword centre on what the 1000 V setting does to range, accuracy, power and safety.

Range at 1000 V

Range is not always one number. One listing says it measures up to 200MΩ at 250V and 500V and up to 2000MΩ at 1000V. Two others give 2000MΩ or 2GΩ, which are the same figure, one lists 1000 Megaohms and one lists 0-1000MΩ. Read the range that applies to the 1000 V setting, not the headline.

Stated accuracy

Accuracy tells you how far a reading can sit from the true value. Three listings state a plus or minus 4 percent figure for insulation readings. The hand crank unit states an accuracy class of 10 and a tolerance of plus or minus 10 percent. One listing states none. A tighter figure matters most near the top of the range.

Power source

Four of the five run on batteries, and one of those lists 6 AA cells as included. The hand crank unit needs no batteries but needs steady cranking at its rated 120 RPM. Batteries suit short spot checks. A crank unit suits sites where you cannot rely on a charged meter.

Safety claims and warnings

A CAT rating describes what circuits a meter is built for. It is an IEC classification of live circuits used in measurement. Only one listing states one, and it reads Cat III 600v, which is lower than the 1000 V test output, so read the manual for what that rating covers. Two listings add high-voltage warnings: a red LED and buzzer during tests.

Extra functions

Some choices are also multimeters. They add AC and DC voltage, continuity, current or capacitance. That is useful if you carry one tool, but it adds modes to get wrong. Our guide to a digital megger compares the display types in more detail.

1000V megger choices at a glance

The five choices in detail

Top choice: the megger and True RMS multimeter combination

This choice bundles a 1000 V insulation tester with a full multimeter. The listing says IR tests run at 500V or 1000V, with a range up to 2000MΩ and a plus or minus 4 percent accuracy. It adds a 6000-count display, True RMS, current up to 20A, capacitance up to 60mF and inductance up to 60H.

The kit includes test leads, alligator clips, a K-type thermocouple, a carrying case and 6 AA batteries. The thermocouple measures from -40°C to 1000°C. The specification line reads IEC and Cat III 600v, and the listing mentions overload protection with fuses and NCV detection.

The limits are plain. No weight or dimensions appear. The voltage line reads 1000V/750V and does not say which applies to AC or DC, so check the manual. Its CAT III 600v claim sits below the 1000 V test output. Skip it if you want only an insulation tester or a stated size.

Second choice: the 2000MΩ meter with a test lock

This choice gives the clearest range statement at 1000 V. The listing says it measures up to 200MΩ at 250V and 500V and up to 2000MΩ at 1000V. It also reads DC voltage up to 1000V and AC voltage up to 750V, and resistance up to 2kΩ at plus or minus (0.8 percent + 6).

A function switch locks the insulation test on, and a high-voltage red LED and buzzer provide warnings during tests. A continuity buzzer sounds below 50Ω. It runs on 6 AA batteries and ships with a shoulder strap and crocodile clips. The specification line reads UL 61010-1, IEC 61010-2-030 and CE, and the weight is 580 g.

The listing contradicts itself on size. The specification says 6.69 x 2.48 x 6.93 inches, while a bullet gives 175×110×62.5mm. Rely on neither. Data hold does not work in insulation mode. Skip it if you want a stated insulation accuracy or a documented size.

Third choice: the digital tester with stated accuracy

This choice offers 250, 500 and 1000V DC and an insulation range from 0.1MΩ to 2GΩ at plus or minus 4 percent. It also works as a multimeter with a 1999 counts display, reading AC voltage up to 750V at plus or minus 1.0 percent and sounding a continuity buzzer.

The display is a 3.5 inch backlit LCD, and the sampling rate is about 3 times per second. A data hold button freezes the reading. It lists a high voltage and short circuit buzzer alarm. It states CE and RoHS and measures 7.28 by 4.53 by 2.56 inches.

The listing has gaps. It states a weight of 2.5 kg, which looks heavy for that body size, and an item count of 32, which cannot describe one meter. The data hold note is cut off, so confirm which modes support it. No CAT rating appears. Skip it if you want a documented ingress rating or a warranty term.

Fourth choice: the rugged digital and analog tester

This is the choice for field conditions. The title gives 250, 500 and 1000 V test voltages in a digital and analog layout. The listing mentions a rubber armoured case, a self-contained protective cover, a live circuit warning, weatherproofing to IP54 and a three-year warranty. It lists a calibration certificate.

It cites IEC 61326 and IEC 61010-1 and weighs 2.2 pounds. The dimensions are listed as 4.25 x 11 x 12 inches, and the style line says 1000 Megaohms Resistance.

It lacks stated accuracy, a display size and a CAT rating, so the standards line is all you have for safety. It also has no multimeter functions listed beyond ohmmeter and voltmeter measurement types. Its listed maximum of 1000 megohms is half that of the 2GΩ meters. Skip it if you want multimeter functions or a documented accuracy.

Fifth choice: the hand crank megger

This one needs no batteries. The listing gives a rated voltage of 1000V, a measuring range of 0-1000MΩ, an accuracy class of 10 and a tolerance of plus or minus 10 percent. You turn a crank to the rated 120 RPM.

It has a three-terminal guard connection, which the listing says removes surface leakage errors on cables in high humidity. The shell is alloy with stainless steel handles. Test wires with alligator clips are included. It measures 8.1 by 4.7 by 5.7 inches and weighs 3.3 lbs.

The limits are specific. The tolerance is the widest of the group. The listing states no display type, so confirm whether it shows a pointer or a number. You also need a steady hand and a steady crank for a stable reading. It has no multimeter functions. Skip it if you want a digital readout or a tight stated accuracy.

Comparison of the five choices

Feature	Top choice	Second choice	Third choice	Fourth choice	Fifth choice
Test voltages	500V / 1000V	250V / 500V / 1000V	250 / 500 / 1000V DC	250 / 500 / 1000 V	1000V rated
Range at 1000 V	Up to 2000MΩ	Up to 2000MΩ	0.1MΩ to 2GΩ	1000 Megaohms style	0-1000MΩ
Stated accuracy	±4%	Not stated for IR	±4%	Not stated	±10%
Power	Battery (6 AA)	Battery (6 AA)	Battery	Battery	Hand crank
Weight	Not stated	580 g	2.5 kg	2.2 pounds	3.3 lbs
CAT claim	Cat III 600v	None stated	None stated	None stated	None stated
Multimeter functions	Yes	Voltage, continuity	Voltage, continuity	No	No

How to choose by situation

You want one tool for the toolbox. Choose the top choice. It adds capacitance, inductance and temperature. For the voltage steps below it, see our guide to a 500 volt megger.

You want a documented range at 1000 V. Choose the second choice. Its listing states the range for each test voltage, which is the clearest of the five.

You want the tightest stated accuracy on a digital display. Choose the third choice, or the first if you want the extra functions.

You work where batteries are unreliable. Choose the fifth choice, and read our guide to a hand crank megger first. For choosing a voltage for a particular job, see megger test voltage and the guide to testing an electric motor.

Worked example: range, accuracy and cranking

You expect an insulation reading of about 800 MΩ on a cable, and you also want to know whether a 1.2 GΩ reading would fit each range.

1. Convert: 1.2 GΩ x 1000 = 1200 MΩ.
2. Against a 2000 MΩ range: 2000 – 1200 = 800 MΩ of headroom, and 1200 / 2000 = 0.60, or 60 percent of the range.
3. Against a 1000 MΩ range: 1200 – 1000 = 200 MΩ over the top, and 1200 / 1000 = 1.20, or 120 percent of the range. It would run off the scale.
4. Apply a plus or minus 4 percent figure to 800 MΩ, assuming a plain percentage of reading: 800 x 0.04 = 32 MΩ, so 800 – 32 = 768 MΩ up to 800 + 32 = 832 MΩ, a band 64 MΩ wide.
5. Apply plus or minus 10 percent: 800 x 0.10 = 80 MΩ, so 800 – 80 = 720 MΩ up to 800 + 80 = 880 MΩ, a band 160 MΩ wide.
6. Cranking: at the listed 120 RPM, a 2-minute reading means 120 x 2 = 240 turns.

Re-check: 1.2 x 1000 = 1200; 2000 – 1200 = 800; 1200 / 2000 = 0.6; 1200 – 1000 = 200; 1200 / 1000 = 1.2; 800 x 0.04 = 32; 800 – 32 = 768; 800 + 32 = 832; 832 – 768 = 64; 800 x 0.1 = 80; 720 and 880; 880 – 720 = 160; 120 x 2 = 240. The arithmetic agrees both times.

The result changes the choice. The 2000 MΩ meters cover a 1.2 GΩ cable with room to spare. The 1000 MΩ meters do not. The listings do not say whether the tolerance applies to the reading or to the scale, so treat the bands as an estimate.

Safety before you use a 1000V megger

Work on mains circuits can kill. A megger applies a deliberate test voltage, so treat its output as hazardous, follow the instrument manual and local electrical rules, and leave panel and service work to a licensed electrician.

According to the Wikipedia article on measurement category, the required impulse withstand voltage varies from 500 V (CAT II, 50 V) to 12,000 V (CAT IV, 1000 V). The same source says IEC 61010-1 requires the maker to make the transient withstand capability known to the user. Four of the five listings state no CAT rating, so say the listing does not state one and look in the manual before you rely on it.

Common mistakes with a 1000v megger

1. Reading the headline range. Look for the range at 1000 V, since some listings give a different range at lower voltages.
2. Assuming CAT III 600v covers a 1000 V output. A category rating and a test voltage are different things. Read the manual.
3. Trusting conflicting sizes. One listing gives two different sets of dimensions. Do not plan a case or bag around either.
4. Forgetting data hold limits. Data hold may not work in insulation mode. Check before you plan to freeze a reading.
5. Ignoring power. A crank unit needs steady turning, and a battery unit needs fresh cells.

FAQ

What is a 1000v megger?

It is an insulation resistance tester with a 1000 V test output. The listings call it a megohmmeter or insulation resistance tester.

Which choice has the highest range at 1000 V?

Three choices list 2000MΩ or 2GΩ. The second choice states it explicitly at 1000V. The fourth and fifth top out at 1000 megohms.

Do I need a CAT rating?

It tells you what circuits the meter is built for. Only one listing states one, so check the manual for the rest.

Is a hand crank megger as accurate as a digital one?

The listing states plus or minus 10 percent for the crank unit and plus or minus 4 percent for three digital meters. Neither is a guarantee, so confirm in the manuals.

Can I use it as a multimeter?

Two choices add voltage and continuity, and the first adds more. The fourth and fifth do not list those functions.

Why does one listing give two sizes?

The specifications and a bullet disagree. Confirm the size in the manual before you buy a case.

What does 1999 counts mean?

It means the display can show values up to 1999. It describes display resolution, not the insulation range.

Bottom line

Choose the top choice for a megger with multimeter extras, the second for a clearly stated 2000MΩ range at 1000 V, the third for a digital display with a stated plus or minus 4 percent, the fourth for field conditions, and the fifth if you want no batteries. Confirm the CAT rating and the range at 1000 V in the manual before you use any of them.

Sources

• Wikipedia: Measurement category: supports the CAT explanation, the impulse withstand range and the IEC 61010-1 requirement