Fisher & Paykel Smart Drive

[vdubnut62]

Go Bob! I like a positive attitude!  But just how does one manage to get around juggling life?
If someone would give me that answer to that question, I would be a wealthy man.
Ron

[BruceM]

Jedon, Transformers, if toroidal, would be more efficient than variacs, which are also toroids, but have  no secondary winding.  The problem is getting the right voltage out; easy with a variac, not so easy with transformer(s).

For an experimental system, with your power level and distance, converting the F&P windings to 120V, single phase, might be the easiest.  You could get the guy in NZ to do that for you. Then a single variac will set the voltage to your 48V charge controller.  What is your charge controller input voltage range? 

[Jedon]

I already have enough of a track record of biting off more than I can chew! Gotta finish up what I'm already eating before biting off too much more... I'm only 40, I have plenty of time left to do fun projects :-)

I don't have a charge controller yet, I have my PV hooked right up to the batteries since the PV outputs 65-69V.

I'll get a charge controller if needed of course, don't need a MPPT right just PWM? Midnight for $200?

[BruceM]

Depending on your PV max current, the Tristar 45 and Tristar 60 look like good PWM, multistage charge controllers.  The former is about $150. 

[Jedon]

I just measured and it only took 2.2 seconds to fill the 5g bucket so 136gpm? Wow a lot of flow in the winter! That would get me in the 1KW range which would be awesome!

[BruceM]

Better winter performance is great- much more lighting, etc. then, and PV performance is at it's lowest. 

So your feed pipe just got much bigger, and you'll have some extra plumbing for more nozzles in the winter, plus an impact on the electronics as well to handle such a wide range of power.

[mobile_bob]

looks like you need two turbines, one for high output in winter and a much smaller one for low output in winter

use the same transmission line, size it for low power, then
use it to transmit the high power at much higher voltage

that will be a fun project in my opinion

bob g

[Jedon]

I could just use a single Harris Hydro turbine with 4 nozzles and a 48V PM alternator. Losses on 600ft of #2 wire should be 10% or so?
This is the easiest and most proven setup but is pricey. The nozzle inputs have valves on them so I can just turn them on and off depending on flow.

[BruceM]

I wonder what 1200 feet of #2 wire will run these days.  Has copper come down in price, or is inflation starting to hit metals?

[mobile_bob]

last i checked the price of copper on the exchange is back up to about recently historic highs
not that the retail market for wire dropped much in the interim that i saw.

i would expect it will be expensive.

myself i would transmit at 480volts minimum over that distance.

bob g

[Jedon]

Ouch, 2/0 copper is $3/ft, could I use Al?

[mobile_bob]

sure you can use aluminum, but why?

far better to get the voltage up and transfer it that way

then you could probably make the 1200ft trip with 10guage

bob g

[rl71459]

How far up is up? Or are you suggesting single conductor runs. The only reason I ask is Multi conductor
cord is insulation dependant...

I'm no expert... but have run into this problem with HV industrial controls. Where it was needed to either
buy special multi conductor wire or make single conductor runs spaced a givin distance apart. The single
runs were cheaper but required much more space.

Rob

[Carlb]

FYI
I agree with Bob G and going to high voltage but if you want to go the aluminum route,
I just added a sub-panel in my basement for my11.2kw solar array.  I used 2-2-2-4 aluminum Service entrance cable  which i bought at home depot for 1.40 a foot.  They also had 2-2-4 cable but i don't know the price but i suspect it should be a bit less expensive.  

[BruceM]

Jedon- I suspected as much on the wire.   There's already the NZ system all engineered for a high voltage run, with step down transformer at your battery end, and you can ask them about how to best cope with your varied flow.  Their small unit can handle up to 1000 watts, so a single unit solution with some seasonal nozzle shutoffs may serve well. 

Perhaps they can offer some suggestions for battery charge current limiting, also.  The Pelton wheel speed must be kept up to keep voltages up, so the battery charger current draw on the microhydro must be limited, somehow.  With asingle phase wiring configuration and a variac, as I suggested before for a homegrown solution, that would be a snap. With a fixed transformer, you'd need  a switching current regulator. (One of the MPPT controllers that limits current would work but it's an expensive solution.)

Since that's probably over your head, electrical hardware-wise,  relying on the vendor to help with your system design might be wise.  Give them you range of flows, your system voltage, and let them know you haven't purchased a solar charge controller yet.  Maybe they'll have a good solution for you, and you can just focus on the water system plumbing and system installation, which is no small task.