How far can you SWER using a pair of microwave transformers?

[Electric-Light]

A microwave transformer has about 1.5kVA capacity and it provides its output with one end grounded to the core and the other end floating.

How effectively could you carry power and how far using one 18AWG for 2100v AC and attaching the cores of sending side and receiving side to a big grounding rod so that you have a SWER system?

(120->2100v) [SWER]----------------------------(2100v->120v)

 

[roger]

Depends on the moisture and minerals at the location.


Roger

 

[beanland]

Not Allowed

Not Allowed

Using the earth as the intentional conductor is not permitted in the USA. SWER is used in aother countries by utlities.

 

[broadgage]

I would advise against such an experiment due to the high voltages and risk of fatal accident. As others post it is a violation in the USA, unless you call it a communications facility or some such get out.

The distance would be considerable in practice.
The current would be only slightly more than 0.1 amp, so if we allow 10% voltage drop, then we have about 200 volts that can be dropped.
#18 is about 35 ohms a mile, or at 0.1 amp about 3.5 volts per mile is lost.
55 miles would be about right, after allowing for a reasonable ground rod resistance each end.
No great accuracy can be claimed, but it would be several dozen miles.

 

[Electric-Light]

From what I've read, NEC wouldn't have any say if the step-up transformer is not permanently wired fixture and is activated with a NEMA 1-15P plug as long as it is not plugged in at the time of code inspection, right?

Would it be under NESC?

Let's say the supports are plastic fishing rods. Wire is a single conductor 18 or 20AWG security system wire. Another loop on the rods distanced about 6" apart can be used in case SWER doesn't work.

120-2100v(using two in series) at farmhouse
2100-240/120v(HV side in parallel, LV side in series with center tap) at detached barn 2,000 ft away at the other side of farm.

But on the serious note, I thought SWER is used by rural utilities? The Dalles, OR to Los Angeles, CA DC intertie also operates as SWER if one of the conductor goes down. Usually its a two conductor +/- 500kV 1MV system. When one is downed, it becomes a + or - 500kV system

 

[broadgage]

I dont see why it would not work, though I doubt that it is allowed !
If the single wire is bare then it would be fatal to the touch, and should therefore be supported on proper insulators and placed at a similar height to utility lines worked at similar voltages.

It would be an interesting experiment under controlled conditions, but I would strongly advise against doing this as a practical means of supplying power to a remote building.
Remember also that microwave oven transformers high relatively high impedance which would result in substantial and probably unacceptable voltage variations with load. They may also only be designed for intermitant use.

More practical means of supplying power to a distant outbuilding include
1) a standard 3 wire 120/240 volt circuit in very heavy cable to reduce voltage drop, simple but expensive except for very small loads
2) Step up to a higher utilization voltage such 660, and then down again to 120 at the far end.
3) Use a PV , battery, and inverter system, probably best for small loads
4) Use a generator, probably best for large loads, and if transportable has other uses also.
5) Obtain a new service from the power company.