Hi all,
I am a co-owner of a stamped concrete business in North Africa.We are struggling getting a steady supply of color hardeners for our projects. We consume several thousand pounds every day. I am looking at identifying recipes to mix locally our own hardeners from silica, quartz, protland...
Hi all,
I am a co-owner of a stamped concrete business in North Africa. We are struggling getting a steady supply of color hardeners for our projects. We consume several thousand pounds every day. I am looking at identifying recipes to mix our own hardeners from silica, quartz, protland cement...
Dear Bill and Pete,
Many thanks for coming back to this topic and thread again and take time to help. I did obtain a lot of information from our field, service, installation and marketing guys on this. There is no standard way of connecting these motors even though this may sound very risky in...
I understand then that we have a whole range of scenarios as far as neutral grounding on the supply side. With a floating one the differential current sensor shoudl not work as there is no return path of the leakage current to the supply.
Thanks for the info
Regards
Karim
Many thanks to Bill and Pete. Your answers are most helpful. If one could develop a 1000 times more sensitive ground fault or stator insulation leakage current differential CT, on what motors could one use it ? I was askd this question at a recent IEEE on Motors and Gens Conf.
Thanks
Karim
Hello
I am interested in learning how industrial motors (1000HP to 50,000 HP MV to HV)and their supplies are connected. More specifically I would like to know if the neutral of the motors and the newtral of the supply side are grounded. Also how does the neutral connection/grounding approaches...
Pirulo,
I am not sure what you are trying to achieve with this formula. If it is to assess your need for purchasing of tape, I think your formula and Pete's improved approach is ore than precise.
If it is for quality control and consistency in insulation build, I suggest you try on a test coil...
Pete
Sorry I did not get a chance to comment sooner. Based on the data I agree there is a clear vibration signature. I doubt it is bearingrelated otherwise it would stay. I will get someone to help with identifying what it can be. Did your expert mention the potential for "intermittent turn...
Carlos
Good points from all. Please check your process capability for similar coils as well. Check the distribtion of DF and TU across all your coil population. Outliers are often difficult to explain without very carefull inspection or even coil dissection. Plot separate histograms for each of...
Hi Pete,
I am new on this Eng-Tips as you know. While doing accelerated aging test on two motors last October we saw the same smoke event followed by normal operation on one of the motors. My engineer said it "burped" and gave white smoke. After shut down and routine insulation testing IR, C...
Electricpete
Many thanks for your help. I happened to have joined Ontario Hydro when that TR 100185 report was being finalized. Great work and very informative data. They tested 4 or 5 motors under different conditions and looked at various test methods and how they correlated.
I wish I could...
Hi everyone,
I am looking for information and references on the possible correlation between motor life/reliability and Capacitance and Disspation Factor values. I am an EE and know about the meaning of C and DF but have never seen decent data showing clearly the value of this test (IEEE28)...
