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Anonymous Poster

insulation test

06/30/2008 10:33 AM

Hi Can anybady help me. how can i test motor insulation resestance and what recommendation value.
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vutronix
Participant

Join Date: Jul 2008
Location: Ho Chi Minh City
Posts: 2
#1

Re: insulation test

07/01/2008 1:30 AM

Ok! Use an Megomet is the best selection for you!

Try it!

Vutronix - http://vutroniq.t35.com

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 vutronix
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vutronix
Participant

Join Date: Jul 2008
Location: Ho Chi Minh City
Posts: 2
#2

Re: insulation test

07/01/2008 1:57 AM

(the image of Megomet)

1 KV Smart Megohmmeter MD-1000R

  • 3 Test Voltages: 250 V - 500 V - 1000 V
  • Auto-Range
  • Guard Terminal
  • Hold Memory
  • Programmable Timer
  • Programmable Pass / Fail Test
  • Continuity /Low Resistance Measurement
  • Voltmeter AC/DC 600 V - True RMS
  • High Voltage Warning LED

The Megabras MD-1000R is a smart, microprocessor-controlled, 1 kV insulation tester for up to 20,000 MO resistance measuring with 250 V, 500 V and 1000 V test voltage. It is a portable, hand-held, battery-powered equipment. Due to its measurement principle (actual voltage and current readings) it is a "true megohmmeter" and so the accuracy of resistance measurement is not affected by any test voltage error.

Technical Specification:
Nominal test voltages250 V - 500 V - 1000 V . Negative., DC Voltage
Resistance Measuring Range 10 kOHm up to 20,000 MOhm @ 500 V and 1 kV, 10 kOhm up to 10,000 MOhm @ 250 V
Short circuit current1,5 ± 0,3 mA
Test voltages accuracy-0 / ± 15% for resistances between 10 MOhm and open circuit
Basic accuracy± 5% of reading ± 2digits
Low Resistance Measurement and Contimuity Tester Range: 0.05 ~ 150 Ohm, Accuracy: 5% of reading +/- 2 digit, Test Current: up to 200mA, Continuity indicator: Activates at 5 Ohm +/- 0.5 Ohm
Built-in Timer5 - 10 - 15 - 30 seconds 1 - 2 - 3 - 5 - 10 - 15 minutes
Pass / Fail Test1 - 2 - 5 - 10 - 20 - 50 - 100 - 200 - 500 MOhm, 1 - 2 - 5 - 10 GOhm
VoltmeterTrue RMS, Range: 0-600VAC/DC, Accuracy: 3% of reading +/- 2 digit
Overvoltage Protection600V
Additional Features•Automatic Polarization Index • Guard terminal • Hold function
Safety Class IEC 61010-1/1990, IEC 61010 1/1992 - 2
E.M.CIn accordance with IEC 61326-1
Power supplyBuilt-in, NiMH battery
Battery chargerBuilt-in, with external power supply of 9V - 0.5A
Operating temperature range-5°C to 50°C
Storage temperature range-25°C to 65°C
AltitudeUp to 3000m
Humidity range95% RH (non condensing)
WeightApprox. 0.5kg
Dimensions202 x 195x 46mm
Included accessories• Measuring test leads, 2.0 m (2) • GUARD test lead 2.0 m (1). • Power Supply. • Manual • Carrying Bag

And more...

Good luck to you!

(Vutronix)

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Shawn_V_Elect
Power-User

Join Date: Jan 2008
Location: Silvis, IL (Quad Cities)
Posts: 141
Good Answers: 5
#3

Re: insulation test

07/01/2008 5:36 AM

As someone else has already said, use a megohmeter, or megger. I personally would use a fluke. You didn't state what kind of motor that you are testing. I will assume an AC squirrel cage motor. basically, you set up the megger for the voltage you wish to test at. I personally will test at approximately double the rated voltage. Test each of your leads T1-T3 to ground and look for greater than 1 Megaohm of resistance. If it is higher than that the motor should run. Everyone has their own standards on the level of resistance allowed on a motor, so if you are with a company I would check what resistance level they are looking for in their standards.

One more thing, when using the Megger, do NOT touch the leads while you are testing. It is liable to be a shocking experience. Also, I would highly reccomend not touching the leads to a friend and watching them jump. Yes, I know it is probably funny, but it can also give them a heart attack, which is bad.

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Aaronmk
Participant

Join Date: Jun 2008
Location: Durban, South Africa
Posts: 3
#4
In reply to #3

Re: insulation test

07/02/2008 3:42 AM

Dear guest,

Welcome! Regarding insulation resistance test on a motor, just to add up to what's already been said to you, use a Megahommeter. Select the test voltage at least double the rated working voltage of the motor.

Carry out the test between the stator windings and earth then between windings only and the readings sould be at least 0.5 megahom in both cases.

Hope this helps!

Note: Sfety first! Observe safety precations at all times!

Aaron

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