Use this chart for an exact figure     Use the voltage specific charts for quick reference

To find voltage Drop: Ohms per ft. X Wire Length X Hydro amps

Example: 200 ft. 6 gauge. Copper wire (100 ft. transmission) at 8 amps

200 X 0.000491 X 8   =   0.786   volts drop

To find hydro voltage:add voltage drop to battery voltage

12.6 +0.786 = 13.346 volts

To find % wire loss from above: Voltage drop from above / hydro voltage

0.786 /  13.346   =   .0589

5.89% for the total wire run, two conductors, each conductor is half.

Electrical inspectors would like to see 2% or less voltage loss per conductor. The Permanent magnet hydro is a dynamic power source that works outside of the usual concerns for motors and other types of generating equipment. The 2% rule is not relevant to the equipment. Most conductors available are rated for temp rise at 2000 volts to 75 C. We can easily waste 20% of the power being generated in each conductor on some of these long wire runs and still not detect any temperature gain at these low voltages. This would result in a drop in efficiency of 36% which is clearly unacceptable except for the longest of wire runs. Sometimes it is about what is possible and not what would be correct. As a rule I rarely will design a system with over 10% wire loss per conductor because there is usually some other option. You can either heat wire or charge the battery. Explore producing at a higher voltage and use a step down transformer/rectifier unit to reduce wire costs.

10% loss example: Hydro 12 amps @ 13.86 volts = 166.32 watts

Battery 12 amps @ 12.6 volts = 151.2 watts

2% loss example: Hydro 12.94 amps @ 12.853… volts = 166.32 watts

Battery 12.94 amps @ 12.6 volts = 163 watts

Quite often the hydro will also increase in efficiency providing another slight gain.

12 Volt DC

The following table shows the maximum transmission distance using copper wire assuming 2 volts drop total. This works out to a little less than 7% loss per conductor or just under 14% total voltage loss for the transmission distance. This is my personal limit for a 12 volt system which is naturally inefficient due to the low voltage. The table also assumes that the battery voltage is approximately 12.6 and the hydro voltage will be approximately 14.6 at the power level indicated. For 2% loss per conductor, the transmission distance will be 30% of the number in the column.

24 Volt DC

The following table shows the maximum transmission distance using copper wire assuming 2.8 volts drop total. This works out to 5% loss per conductor or 10% total loss for the transmission distance. The table also assumes that the battery voltage is approx. 25.2 and the hydro voltage is 28.0 at the power level indicated. 2% conductor loss is 40% of the number in the column.

32 Volt DC

Still in limited use, the equipment used is primarily remnants of the marine industry. It was also the old standard for rural electrification and telegraph up to the 1950’s and military applications prior to WW2 in the U.S. This chart is being shown to accommodate Nickel Iron batteries on a 24 volt system to more accurately size the hydro wiring which is gaining in popularity. Personally I don’t care for the efficiency of the Nickel Iron battery and I encourage you to dig into the issue before implementing them. Read the section on Nickel Iron batteries for more information. The following table shows the maximum transmission distance using copper wire assuming 3.32 volts drop total. This works out to 5% loss per conductor or 10% loss for the transmission distance. The table also assumes the battery voltage is approximately 33.2 and the hydro voltage is 36.52 at the power level indicated. 2% conductor loss is 40% of the number in the column.

48 Volt DC

The following table shows the maximum transmission distance using copper wire assuming 5.6 volts drop total. This works out to 5% loss per conductor or 10% total voltage loss for the transmission distance. The table also assumes that the battery voltage is approximately 50.4 and the hydro voltage is 56.0 at the power level indicated. 2% conductor loss is 40% of the distance listed.

62 Volt DC

This table is for sizing the maximum distance of the hydro wire run in a nominal 48 volt Nickel Iron battery system using copper wire assuming 6.2 volts drop total. This works out to 5% loss per conductor or 10% total voltage loss for the transmission distance. The table also assumes that the battery voltage is approx. 62.0 and the hydro voltage is 68.2 at the power level indicated. 2% conductor loss is 40% of the distance listed. Read the section on Nickel Iron batteries for more information. The table is also useful as one of the voltages commonly found by the MPPT controllers.

75 Volt DC

This Table is strictly for figuring the maximum distance hydro wire run at a voltage commonly found by some of the MPPT controllers using copper wire assuming 7.5 volts drop total. This works out to 5% loss per conductor or 10% total voltage loss for the transmission distance. The table is built to reflect 75 volts at the controller and 82.5 at the hydro. This table can be used at any voltage if you scale the numbers by percentage. That includes the watt figure as well. An increase of 10% on voltage will yield 10% longer distance and vice versa. The voltage drop also changes proportionally. 2% loss per conductor is 40% of the distance in the column. Read the section on MPPT controllers

120 Volt DC

The following table shows the maximum transmission distance using copper wire assuming 9.6 volts drop total. The 120 VDC system is used extensively around the world but is effectively outlawed in the US. Fear and misunderstanding from the people entrusted with over-protecting us? A pretty silly idea considering they allow Solar systems operating close to 1000VDC. The table assumes 4% loss per conductor or 8% voltage loss total. 2% is 50% of the distance listed. This table also shows the highest MPPT voltage generally found by the Midnight 250. We can also build a step down TR/rect. unit from a higher voltage to 120 VDC to help reduce wire costs.

DC transmission versus AC transmission

The biggest exaggeration ever told in the electrical world and repeated until accepted as fact might be: “AC travels further than DC “………well….OK. Reactive capacitance can change the effective wire loss in some 3-phase AC circuits which is applicable to some of our 3-phase wild PM units but otherwise…

NO

The truth should go something like this: AC travels slightly further than DC under certain circumstances and it is easier and more economical to transform into usable AC and DC power at the point of use. AC is more commonly found at the higher voltage levels and is easier to produce at those voltage levels.

Figuring Single Phase AC current per conductor

Watts/Volts=Amps and then, Amps/Power factor=current per conductor

1400 watts/200 volts = 7 amps, 7 amps/0.85 PF= 0.824 amps

Most of the time the power factor is at or close to 1.0 however.

120 Volt AC single phase

For use with our PM 1032 hydro up to 800 watts either direct load resistive heating or incandescent lighting at fixed load and water volume or to a step down transformer rectifier unit for battery charging. These are less efficient that our 3-phase models but makes two wire transmission possible. This table can also be used for conventional AC hydro wire sizing at 120 volt 60Hz. The table assumes the conductors are copper and allows 4% loss per conductor or 8% loss for the transmission distance. 2% loss is 50% of the distance listed. Inherently regulated AC generators will need to be within the 2% range for proper operation.

240 Volt AC Single Phase

Same as above except 240 volt. 4X the distance or 4X the power of 120 volt

480 Volt Single Phase

Same as above except 480 volt. 4X the distance or 4X the power of 240 volt

Figuring 3-Phase AC current per conductor
Watts/Line-to-line voltage X 0.667 = current per conductor. The range is 0.61 to 0.71 depending on head and volume of the water source and resultant operating frequency (PF). There are so many variables involved with wild frequency and the math is not simple, that this guide is intended to show distances that are most likely only. Sites with less than 50 ft. of head should be reduced about 3%.

—–Caution—-

The High voltage turbines should be installed inside some type of suitable dry and securable structure for safety reasons. We assume no liability for poor application of our products.

3-Phase 120 Volt 3 wire

This table is for use with our long distance transmission unrectified versions of Model PM 1800 and PM 2500 which is wild 3-phase. The frequency range is determined by head and volume but usually between 50 and 150 Hz. The voltage will also depend on battery state of charge after the TR/rect. unit. The voltage range will usually fall between 80 and 120 VAC line-to-line. Most will be around 100 VAC line-to-line and this table is built on that assumption. 120 volt 3-phase is unusual but some sites do not meet the rotational minimums to produce a higher voltage. The table assumes that the conductors are copper and in PVC conduit. The table also assumes 4% loss per conductor or 8% total voltage loss for the transmission distance at the power level indicated. When sizing wire for conventional AC generators, the distances can be increased by 20% depending on the type of generator to allow for the higher operating voltage. 2% conductor loss is 50% of the distance listed.

3-Phase 240 Volt AC 3 wire

Similar to 120 volt above except 240 VAC. The voltage range will usually fall between 160 and 240 VAC line-to-line. Most will be around 200 VAC line-to-line. All other assumptions are the same. Open circuit on these turbines can be 350-400VAC. 2% loss per conductor is 50% of the table distance.

4X the distance or 4X the power of 120 volt

3-Phase 480 Volt AC 3 wire

Similar to the 240 units above except 480 volt. The voltage range will usually fall between 320 and 480 VAC line-to-line. Most will be around 400 VAC. All other assumptions are the same. Open circuit on these turbines can be 700-800 VAC and may require special wire. 2% is 50% of the table distance

4X the distance or 4X the power as 240 volt.