Overhead line Distance

Status
Not open for further replies.
Re: Overhead line Distance

Its not the voltage from the transmission line you need to worry about. Its that cell phone right next to your head.... :D :D :D

I once had a senior emag profesor who when asked about high voltage transmission lines and induced voltage at ground level went into a 2 week explanation of why you shouldn't worry about it. The lecture began along the lines Charlie's post and then really got complicated. His conclusion was that the most dangerous source of unwanted electromagnetic energy was your microwave not the cell phone or the power line.
 
Re: Overhead line Distance

rattus,
If I connected the common to the EGC of an outside switch, I measure some 3 volts. Now this could be inductive pickup on the EGC.
Click to expand...
Or it could be the utility primary voltage drop.
Don
 
Re: Overhead line Distance

Don,

That is a possibility of course, but the house where I did this is empty with hardly any electrical load. I will go back and make more more measurements to try to dope it out.

Speaking of voltage drop, ours dropped 240V about 4:30PM and didn't come back until midnight. Sure do miss that stuff. Couldn't even make coffee!

I think some gusty winds blew a tree into the lines or something like that. Neighbors down the street on a different transformer were OK. Phone was out too.

[ November 28, 2005, 01:53 AM: Message edited by: rattus ]
 
Re: Overhead line Distance

Miles, you have no doubt heard the story about the melted candy bars in the screen room. World's largest and first microwave oven. I have heard that people were sickened by the radiation, but do not know if the damage was permanent.
 
Re: Overhead line Distance

rattus,
That is a possibility of course, but the house where I did this is empty with hardly any electrical load. I will go back and make more more?measurements to try to dope it out.
Click to expand...
The local load at the house is not a source of this voltage. I am speaking of the voltage drop on the utility primary neutral between its source and the point where you connected to the EGC. The primary and secondary neutrals are bonded together at the utility transformer and this bonding will energize the secondary grounded conductor and the building equipment grounding system to this voltage. You would measure this voltage from any point on the grounded/grounding conductors to "remote earth". That is earth that is a number of feet away from any grounding electrode system. This primary to secondary grounded conductor bonding is also often the source of the "stray" (NEV) voltage that causes problems on dairy farms and with pools.
Don
Don
 
Re: Overhead line Distance

Don, I see your point, but secondary neutral current also flows in this conductor for short distances of course. It seems that this current would be much greater than the primary neutral current which is somewhat balanced. My scenario is a 4-wire, 3-phase system with 1-phase transformers
 
Status
Not open for further replies.
Top