GaryS - I have no pics but they do/did exist in Australia in the outback to the farms. I worked on the design and build of them. They have not been installed as new installations here since about 1975 as far as I am aware.
USA Farm Power supply
- Thread starter iant
- Start date
I often find myself dealing with stuff on farms. It is still what you remember. Three-phase isn't common at all. I install quite a few phase converters.
danw
Lifetime Supporting Member
Rotary or VFD?
Gene Bond
Member
Dan: We do both or either, depending on the application. We've done up to 350hp on a remote pumping application for a mine flood. Most of the irrigation systems around here have vfd's for the 3 phase supply.
Rotary and solid state. I'm doing a few VFDs this week to free up power on the solid state converter. Those power electronic ones are super nice.
GaryS
Member
well i have been at this since the 70's and it not the first time Wikipedia got it wrong remember they are an open source and anybody can post anything their
in the 1800's when the first telegraph came out they used an earth return each station had it's own 48vdc battery and mechanical relay as a receiver and their was no end to problems and reliable. you may get away with it if the only load was an incandescent bulb but light output would vary depending on the total loop resistance.
but if you are going to run a motor it's going to be a problem
if it was reliable at all why do the power companies always run a return and the primary feed line miles of copper wire is a big expense I am sure if they could get away with it they would. remember on a 3 phase system for each wire you have 2 return conductors
single phase feeds have the one side of the transformer connected to the return and the return is bonded to earth. At least one leg of the secondary from the transformer is also bonded to the same bonded conductor
if i had a client that insisted on using an earth return system i would walk away from it I am not about to have to buy then new equipment because of a floating supply voltage
let alone the risk of somebody getting electrocuted.
in area all new services must be UL inspected before the power company will supply power. Frankly I always welcomed their inspection once they put the sticker on then my liability is greatly reduced and they will never allow an installation with out both a return wire and the service is bonded to earth
I don't know about other countries but here grounding / bonding is a big deal and must be done correctly and you can not do that with any earth return
you can have a single phase or 3 phase system with out a natural but you always have a return as we all know electricity dose not work with out a complete loop path
I can speak from experience the worst shocks I have ever received were on a open natural where the return path found it's way through the earth
you can take all the chances you want I will not
By the way I did look up the same Wikipedia posting before i posted the first time so it nothing new
in the 1800's when the first telegraph came out they used an earth return each station had it's own 48vdc battery and mechanical relay as a receiver and their was no end to problems and reliable. you may get away with it if the only load was an incandescent bulb but light output would vary depending on the total loop resistance.
but if you are going to run a motor it's going to be a problem
if it was reliable at all why do the power companies always run a return and the primary feed line miles of copper wire is a big expense I am sure if they could get away with it they would. remember on a 3 phase system for each wire you have 2 return conductors
single phase feeds have the one side of the transformer connected to the return and the return is bonded to earth. At least one leg of the secondary from the transformer is also bonded to the same bonded conductor
if i had a client that insisted on using an earth return system i would walk away from it I am not about to have to buy then new equipment because of a floating supply voltage
let alone the risk of somebody getting electrocuted.
in area all new services must be UL inspected before the power company will supply power. Frankly I always welcomed their inspection once they put the sticker on then my liability is greatly reduced and they will never allow an installation with out both a return wire and the service is bonded to earth
I don't know about other countries but here grounding / bonding is a big deal and must be done correctly and you can not do that with any earth return
you can have a single phase or 3 phase system with out a natural but you always have a return as we all know electricity dose not work with out a complete loop path
I can speak from experience the worst shocks I have ever received were on a open natural where the return path found it's way through the earth
you can take all the chances you want I will not
By the way I did look up the same Wikipedia posting before i posted the first time so it nothing new
I'm sorry, but it does exist, and it is in use in parts of the world today.
https://www.engineeringnz.org/programmes/heritage/heritage-records/single-wire-earth-return-swer/
A master's thesis from the 70's on the subject:
https://scholarsmine.mst.edu/cgi/viewcontent.cgi?article=6061&context=masters_theses
And for good measure, a discussion on Mike Holt's forum on the issue.
https://forums.mikeholt.com/threads/single-wire-earth-return.146859/
We do have a couple way out in the boonies here in Kansas for certain sections. I'll take a picture next time I happen to find myself working near one that is still in service.
Last edited:
GaryS
Member
Interesting that you want to beat this dead horse some more
Fools are born and die every day and most fools die at a young age
As I have said before and I will repeat show me, pictures speak louder than words
Pictures of the end step down transformer or usage and the source.
Everything works in theory and on paper but in the real world they fail this is one of those times. As I have said I have seen it and I have had to fix it.
You guys are free to do what you want, wire things the way you want as long it doesn’t reflect on me. It wouldn’t be the first or the last job I walked away from
There is a saying you touch you own it. I have had people tried to bring me on a job after they have it screwed up and have do some minor part then when things go bad down the road want me to fix it all for free. I didn’t bite but they keep trying. When I was still doing construction the inspection company I used told me many time when I called for an inspection that they would save the trip and just mail the sticker to me for me inspection was unnecessary but I always requested they come on site on some occasions the sticker would be there before I arrive to do the work.
When I started out the one master I worked under helped install the very first electrical system in several local cities he even helped build some of power generating station and the always had a wire return
As good example of what looks like an earth return ( only 1 conductor and earth return ) in not what it looks like. I have lived all my life within walking distance in fact as a child I would walk along the system long before I knew what electricity was. The electrified rail road system both the high line and catenaries are single wire ( It was PRR now it Conrail Amtrak service. I believe the high line is 120KV and catenaries is 13KV the return path is actually the rail the train runs on so when you walk across a rail road track the rails are a conductor for a 13KV power system. I know it looks like it an earth return but the rail is actually the return
The both rails are bonded together at the joints, some places they run an uncovered conductor on the steel support towers in addition to the rails. Those conductors are bonded to the steel support towers and those towers have ground rod or conductor at each tower to bond it to the earth all to keep the ground voltage to a safe level. ( an side note the electrified rail system in the us runs on 25hz they have special generator at the power plants just for them.)
About once a year they find somebody electrocuted along the tracks it sure fire cure for copper theft. On damp overcast days if you walk along the tracks you can see the electricity arc / jump across the support insulators, it is safe the return is bonded to the earth. But if they tried to run the trains on a single conductor line with just earth return, just crossing the track could get you killed and the supply voltage to the locomotive would be all over the scale and unusable and be unreliable
Just as a reference those engine’s are 3,000 to 6,000 HP each depending on the exact engine and I have seen as many as 6 engines on one train
To close up it would be very foolish and dangerous to use any earth return system.
Electricity is funny and dangerous to work with .
Some years ago some farmers in the Midwest ran a single wire fence beside the transmission lines to power the lights on the farm it did work but the fence was a loop and it was inductive coupling from the power lines. The power company tried to stop it or make them pay but as it turned out you are allowed to run wire on your own property so free electricity.
In short earth return is a good theory but not usable.
Fools are born and die every day and most fools die at a young age
As I have said before and I will repeat show me, pictures speak louder than words
Pictures of the end step down transformer or usage and the source.
Everything works in theory and on paper but in the real world they fail this is one of those times. As I have said I have seen it and I have had to fix it.
You guys are free to do what you want, wire things the way you want as long it doesn’t reflect on me. It wouldn’t be the first or the last job I walked away from
There is a saying you touch you own it. I have had people tried to bring me on a job after they have it screwed up and have do some minor part then when things go bad down the road want me to fix it all for free. I didn’t bite but they keep trying. When I was still doing construction the inspection company I used told me many time when I called for an inspection that they would save the trip and just mail the sticker to me for me inspection was unnecessary but I always requested they come on site on some occasions the sticker would be there before I arrive to do the work.
When I started out the one master I worked under helped install the very first electrical system in several local cities he even helped build some of power generating station and the always had a wire return
As good example of what looks like an earth return ( only 1 conductor and earth return ) in not what it looks like. I have lived all my life within walking distance in fact as a child I would walk along the system long before I knew what electricity was. The electrified rail road system both the high line and catenaries are single wire ( It was PRR now it Conrail Amtrak service. I believe the high line is 120KV and catenaries is 13KV the return path is actually the rail the train runs on so when you walk across a rail road track the rails are a conductor for a 13KV power system. I know it looks like it an earth return but the rail is actually the return
The both rails are bonded together at the joints, some places they run an uncovered conductor on the steel support towers in addition to the rails. Those conductors are bonded to the steel support towers and those towers have ground rod or conductor at each tower to bond it to the earth all to keep the ground voltage to a safe level. ( an side note the electrified rail system in the us runs on 25hz they have special generator at the power plants just for them.)
About once a year they find somebody electrocuted along the tracks it sure fire cure for copper theft. On damp overcast days if you walk along the tracks you can see the electricity arc / jump across the support insulators, it is safe the return is bonded to the earth. But if they tried to run the trains on a single conductor line with just earth return, just crossing the track could get you killed and the supply voltage to the locomotive would be all over the scale and unusable and be unreliable
Just as a reference those engine’s are 3,000 to 6,000 HP each depending on the exact engine and I have seen as many as 6 engines on one train
To close up it would be very foolish and dangerous to use any earth return system.
Electricity is funny and dangerous to work with .
Some years ago some farmers in the Midwest ran a single wire fence beside the transmission lines to power the lights on the farm it did work but the fence was a loop and it was inductive coupling from the power lines. The power company tried to stop it or make them pay but as it turned out you are allowed to run wire on your own property so free electricity.
In short earth return is a good theory but not usable.
PLCnovice61
Member
I also will add l'm afraid Gary you are incorrect, SWER is alive and well in Australia and New Zealand and if it was dangerous l can assure you it wouldn't be used. I not saying it is the best practise, but it is still in use as we speak.
I was in the belief that MEN wasn't how the USA did power, or it didn't use to be, as l have worked on onshore oil rigs (back in the 70's) from USA and they didn't have a MEN system, l just thought that was how you guys did it (floating earth, no earth no shock potential) just being different to all the rest of the world.
I was in the belief that MEN wasn't how the USA did power, or it didn't use to be, as l have worked on onshore oil rigs (back in the 70's) from USA and they didn't have a MEN system, l just thought that was how you guys did it (floating earth, no earth no shock potential) just being different to all the rest of the world.
I don't think anybody is arguing that SWER is safer, or "better" than currently used practices. It's just being said that there are older, existing installations, put in by utility companies, not individuals, that are functional. I don't believe anyone is trying to put it in for a new installation.
As for around here, most all of the rural, farm distribution is 3 phase, 4 wire overhead, 7200V to neutral. Shorter runs to isolated destinations are sometimes 2 wire, single phase overhead. Many older underground irrigation secondary conductors are 480V high leg corner grounded Delta. Newer services to irrigation are still high leg Delta, but with a 4th ground wire. Non irrigation loads are typically 480V Wye, 277 to neutral.
As for around here, most all of the rural, farm distribution is 3 phase, 4 wire overhead, 7200V to neutral. Shorter runs to isolated destinations are sometimes 2 wire, single phase overhead. Many older underground irrigation secondary conductors are 480V high leg corner grounded Delta. Newer services to irrigation are still high leg Delta, but with a 4th ground wire. Non irrigation loads are typically 480V Wye, 277 to neutral.
One of those was a New Zealand power engineering site explaining how that transmission system works. It is a shame that you have been in the business this long and never learned that you should never stop learning.
I'll do you one better than a picture. Here is a video.
https://www.youtube.com/watch?v=4yHrJEw2T3Q
GaryS
Member
All I can say is good luck with it
Animals are more susceptible to it then we are to current passing through the earth
i have seen the avoid arears because of current flow in ground.
how are you going to control the ground resistance that going to have a big effect on voltage regulation
in the US we use a standard 3 phase no natural on the transmission lines
code requires that one point in all power supplies be bonded to the earth for safety
the secondary of a step down transformer is considered a separate power source
natural just means that that conductor is at the same potential as the earth around it
ground conductors are never allowed to have load current flow it is never considered a current carrying conductor when designing a system
even DC power supplies are required to be bonded to earth but you don't see it in 24VDC supplies because supply voltages below 50V is exempt
Grounding in US is a very big deal carefully considered designing a system
Animals are more susceptible to it then we are to current passing through the earth
i have seen the avoid arears because of current flow in ground.
how are you going to control the ground resistance that going to have a big effect on voltage regulation
in the US we use a standard 3 phase no natural on the transmission lines
code requires that one point in all power supplies be bonded to the earth for safety
the secondary of a step down transformer is considered a separate power source
natural just means that that conductor is at the same potential as the earth around it
ground conductors are never allowed to have load current flow it is never considered a current carrying conductor when designing a system
even DC power supplies are required to be bonded to earth but you don't see it in 24VDC supplies because supply voltages below 50V is exempt
Grounding in US is a very big deal carefully considered designing a system
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