MEGGERING A MOTOR PHASE TO PHASE | Information by …
2011年12月24日 · So, if you have 480 volt motor, we look for a minimum of 1.5 megohm or we won't start it. If a motor has to have heat applied to get the megger reading up, then it will need a rewind eventually as the insulation is either tracking to ground or absorbing moisture. On a good motor, a megger reading between phases will show a short.
Megging a 3 phase 480 volt motor - Electrician Talk
2011年7月9日 · Say for example, a motor is put in and reads 40 megs or so for the first 3 years it is operating, and then you suddenly see a drop to say 20 megs, the motor is still in great shape, but that is a very significant drop. Some shops may say that the motor should be megged again at a later time to see how much it changes.
megging a motor wired up - Electrician Talk
2009年1月14日 · success, the megger is used to measure the integrity of insulation on mostly motor windings. we normally megged A-B, B-C, C-A, first open the motor disconnect. if your megging a few branch circuit or MCC feeders, a standard ohmeter should be fine.
Megging / Ohming a Motor | Information by Electrical …
2018年3月25日 · Depending on the size of the motor. Most of ours are pass/fail and we do not do predictive maintenance, or haven’t for some years now. It’s a good idea if you can schedule down time and keep proper records. On occassion we open all the leads and meg for winding to winding faults if it has passed a ground fault test.
What are expected Megger readings? - Electrician Talk
2013年12月28日 · It is a 500 volt/ 200 meg hand cranked. My question is, everything I meg reads infinity or at least over 200 megs. I guess that is good if the readings are correct but I expected some variance. When I take my readings I Disconnect all three lines from the motor, Connect the earth line to the motor grounding lug or frame.
What is an acceptable megger reading? - Mike Holt's Forum
2010年1月9日 · Example a run of 500 mcm 3 phase testing you get odd readings like 400 meg on b to c or 25 meg on a to b lets say different readings not the same . Most electricians pull it out and say its too low dry up the ends recheck it will come up that 25 now becomes 125 meg or it maybe get higher let it dry out one day or cut it back a few inches it has ...
You can't meg a single phase Motor? | Information by Electrical ...
2009年11月2日 · I would love to hear some of your input on this matter, as Im trying to understand...this motor is a single phase-cap start with a thermal protector. It is gfi protected (driving a large fountain) It trips the gfi erratically and I only wanted to meg the windings ( and submerged cord) to make sure there is no leakage to ground to cause a fault.
Motor Megs out Bad, Then Runs? - Electrician Talk
2020年1月1日 · I disconnect wires at motor and megged at studs in motor junction box. Still reading all three shorted to ground. (Tested Meg out on another motor, work fine) Tested another Identical machine (we have several). Disconnected from VFD and megged clear. Plan was to pull motor on day shift ad send it out. Two electricians verified my readings.
Acceptable Phase to ground resistance - Electrician Talk
2016年10月24日 · I've heard 1 meg per volt (500 megs for a 460 volt motor) , I've heard anything less than a zillion megs will cause an immediate burn up and untold billions of $$$ in damage.....lol. Personally, I've seen motors that megged less than 50K last for years. I've also seen ones that sat unused for a while and meg 10K burn up in a couple of hours.
motor meg. | Information by Electrical Professionals for Electrical ...
2005年1月19日 · Re: motor meg. To: buzzlectric, buzz, I have a manual that the AVO company has sent to me. This company was the former Biddle Megger company. I have one of their manuals, called " A Stitch in Time". It is a complete guide to Electrical Insulation Testing. On page 45, they discuss the One-Megohm Rule, and what that means is this.