Insulation tester - what brand/type is ideal for electric motors 1

[simpleoelectrician]

Hello,
I have been looking on the net for a insulation
tester. I intend to use it mainly for testing motors.
I would like know what you would consider to be the
ideal tester for the task.

I have also been trying to locate information on
testing procedures. It has been very difficult to
find such information. I tried a search at this site
with zero results.

Do you know of any sites with motor insulation testing information? Do have any tips for testing?
I would greatly appreciate any information.
Respectfully,Ruben

 

[edison123]

There are many types of motor testers

Megger - Testing the insulation resistance and polarization index of windings (Avo, Fluke, Kyoritsu)

Surge Tester - Testing the turn-to-turn insulation, reversed coils, etc. (Baker, PJ Electronics)

AC HV test kit - Testing the high voltage withstandability of windings (many make them, google for ac hv tester)

DC HV test kit - Non-destructive (within reason) testing of the winding dielectric strength of winding (Google for dc hv tester)

Micro-ohm meter - Testing the winding DC resistance (Avo, Fluke)

* I would go green if only I were not yellow *

 

[waross]

My primary tools were a hand cranked megger with a 1000V scale, a 500V scale, and a 6V low ohms scale, also a clamp-on ammeter and a good quality multimeter. The 6V low ohms scale on the megger will do some of the work of a micro-ohm meter on motors up to about 5 or 10 HP. These located about 99% of my motor problems. Once or twice I have had to send a motor into a good winding shop. I had a motor overheating for no apparent reason. The motor shop determined that there was an internal fault in the casting of the aluminum squirrel cage in the rotor and arranged for a warranty replacement.
But times change and if I got back into service work in North America I would probably add equipment to measure total harmonic distortion, and possibly some type of multi channel recorder, maybe laptop based. Temperature measurement would also be good.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[flexoprinting]

Hello


Here is a good PDF from

http://avointl.com/,

Fluke of coarse also has some excellent procedure information.

 

[Zogzog]

What voltage motors are you testing? You want to get a Megger that has the appropriate test voltages and for motor teting one that calculates your DAR and PI for you. If you have a lot of motors then get one with data storage.

 

[jraef]

I have never owned anything but my Biddle Megger (now AVO). No failures or problems in 25 years.