what's the best megometer for a decent price
I apologise in advance if this question has been asked before, but I was wondering what megometer was thought to be a good buy for a decent price. I need to get one and the one I choose will become the company standard so any help would be appreciated.
SUPCO M500 ABOUT $100 WORKS WELL
The M500 is quite possibly the worst megohmmeter ever made.
Originally Posted by HVACR2012
If you are using one as a one time pass/fail test for condemning compressors, you are most likely condemning a lot of perfectly good compressors.
Nah, it is 2nd to the Supco megohm meter it replaced.
Originally Posted by hvacrmedic
If more government is the answer, then it's a really stupid question.
mine has served it's purpose through the years I've had it
It`s better to be silent and thought the fool; than speak and remove all doubt.
What the heck does 100 bucks get you in a megger?
When I buy an instrument like a megger I look for certification from a testing authority.
A bunch of green and red LEDS don't cut it. You aren't just looking for a ground resistance value, you are evaluating the dialectical strength of the winding which is expressed in mega ohms.. Thru RSES training we used an old crank mega ohm meter and the idea was if you got a bad reading it was most likely moisture in the system conducting a path thru micro flaws in the windings.
A deep vacuum was called for and a new LLFD and another megger test was conducted to evaluate dielectric improvement .
I had to dig deep in my SAMs just to make sure these facts.
( I already knew them to be true but I just wanted to be sure)
I would only buy a direct reading megger. It lets you know the TRUE state of you windings.
Supco sold a whole bunch of micron gauges that show only an LED at a certain micron level but no actual digital reading.
Would you trust one of those to day or would you buy a BluVac? Same logic applies to an instrument as important as a megger.
I tend to agree with HVAClover on this one, although not as stern in my objections. A megaohmmeter is a useful tool with hermetic compressors. It is just that, a tool, among many others. I have used them as a final check before condemning a compressor. Mine is older than most of you guys. I just bought one of the Exetech analogs as my old one is tired of being bounced around in the back of the truck.
But there is no single tool or meter that will do everything for you.
In my opinion, stick to the analog meters when reading MegaOhms.
I agree w/ hvaclover. I don't know how good extech products are but they have a real megger for under 200
For our company that does res. service only, a 'megohm' reading is just an indication of the windings insulation.
For a GM plant that monitors the motors for an assembly line, I would buy the best one possible.
a megger was designed for a hermetic comp, not an open motor. but I'm sure a megger is misapplied like a lot of instruments.
Originally Posted by danielworkerbee
I bought a fluke 1587. It's very handy and have used it several times. Wasn't too terribly bad on price either