jraef
There is an interesting technical paper that describes what sjvanhecke described in his post.
Mrs. Bella (the author) have worked in this area and maybe she can help You. I pasted the information below...
Stonemug
From your post, I understand that you have detected power frequency hum in the communication cables, maybe your shield is part of a ground loop of the power system ground; verify this.
The site below, shows a good graphical description of some of the causes and solutions of your noise...
jraef
As you said this gas is corrosive, especially to the copper wires and bars. I recall working in a Hydroelectric plant that the air in the whole area smelled like rotten eggs due to decaying organic matter in the lake. After several years this gas was corroding everything made of copper...
Jpr2004
Please check thread237-102768.
You cannot add currents arithmetically; your KWHR meter is telling you the truth, your A/C is consuming more power than the motors. There is an important reactive component in your input and output currents in your setup that do not contribute to the real...
Flickstar
By Grounding both ends of the shield you will have circulating currents in the signal wires, the reason is that the shield will be in parallel with the power ground that connects both equipments. When there is a flow of current in your shield you will have magnetic field right next to...
dafo74
I agree with Mstrvb19, this is a complex issue. You need to use a computational model which includes all the hydro, thermal players such as generators, IPPs, transmission and distribution networks etc. which determines the optimal operation of your network (least cost), This can affect...
wr180561
I think you do not have a real fault in the windings, if that were the case you will have other symptoms on your machine. An internal fault in a generator rapidly becomes catastrophic.
Looks that the relay tripping is dependent on the loading of the generator. Did the generator tripped...
Everst
You have a mechanical background, I do not know how familiar you might be with these solutions we are suggesting to you, but here are some additional comments.
I agree with skogsgurra explanation, some type of insulation must be provided to the bearing (Ceramic, Insulated pedestal etc.)to...
Everest
I agree with DickDV; this type of arrangement have been used for decades in the gas and steam turbines multimegawatt generators.
You need a grounding brush riding on the shaft to give the shaft induced voltages safe path to ground, what is happening is that an enough high potential...
axd38
Peebee is right but the job is already done, it looks that the manhole is at a higher level than the panel.
I pressume that you cannot deenergize the panel for a long time.
Your best bet in this case besides of installing a new conduit section (difficult & expensive but best solution), is...
yulinios
In general there is no best way to clean a motor in service, and this action must be done as a last resource.
Because you do not have full access to the windings with the motor end covers in place it will be very difficult to do a complete winding cleaning.
What will happen is that the...
EEAOC
These readings are not unusual, they are telling you that the ph. A have very low insulation resistance to ground and the other ph. are ok. What are the readings between phases? You must look for the cause of this low reading, probably the cause of the low reading is in a very localized...
kkgg
Be careful with the extra flexible cable as the inner bunches of strands in this type of cable can slide out of the mechanical or compression type of connectors resulting in a loose connection later; when the bends (as in a tight enclosure) in the cables are too short radius or too near to...
durf208
Your question is not "dumb" is a perfectly valid question, you were told right, any 2 phases can be exchanged to reverse rotation in a 3 ph. motor, no harm will be done to it, but be careful because the load it drives might not tolerate reversal of rotation like a centrifugal compressor...
