Retro fitting a Classic into an existing Harris Hydro system.

[SolaRevolution]

Help, please.

I'm working on a major up-grade project with two Harris micro-hydro generators. 
It was originally a 110v battery system with a Heart inverter from Michigan Energy Works. It had hydro and PV all feeding in to the battery buss and several diversion loads managed manually.

It is now a XW6048 120/240 system with Outback FMs for the PV (Arcos, Solecs, Siemans)
For now there is only budget for reconnecting one of the hydros.

I spent some time on the phone with Don Harris about this. He remembers the hydro installations and says they are PMs with #19 wire and high voltage diode bridges.  I told him that I wanted to put them into a MPPT controller.  He said something to the effect of this being a new trick for an old dog. His greatest concern was high voltage spikes which would come if the controller suddenly went to open circuit. The hydros have existing 2 wire feeds from the generators to the power room. I isolated the output of the rectifier and got 370 voc.

I've got another installation with a Hi Power turbine (180 max voc) and after talking with Derek I got a Classic 200. That system is working well. The owner is not too technical but with some fine tuning of the nozzles with the help of his neighbor Ross Burkhardt, reports a fairly steady output around 325 watts. (dithers slightly +/- 5watts).  He has also seen the system hit bulk voltage when the sun came out and hit the PVs. He did not look to see what the Classic was up to at the time but saw that it was still humming along later that evening.

Anyway, as I understand it, this old Harris system has a voc which is too high to allow the Classic to regulate the incomming hydro power.  Derek (Hi Power) has recommended I get a classic with 4.2 firmware, set it for hydro, turn off the arc fault and  GFI, set it for "insomnia", get a diversion load and open the valves slowly.

My questions:
Does all of this make sense?
Are there Classics shipping with 4.2 yet?
Should I get a Classic 250 or does it matter which one since the voc is too high for any of them?
Are there other settings to be concerned with?
Should I load the new firmware on the existing Classic/Hi Power system even though it seems to be working fine?
What else should I consider?

Thanks boB, Ryan and anyone else...

Alex Aragon


(Don wants to know how this all works out too. )

[boB]

Hi Alex.   It's been years since I've talked with Don.   I hope he is doing good.  He's a great guy.
I've also been working some with Derik as you probably know and the tracking will just get
better and better as I get time to tweak.

I would leave the Classic you have alone for now since it is working OK. You can always
update software later.

On the Harris, was that 370V without a capacitor ?   I don't know if the "spikes" are
short or if it is real DC.  If short enough spikes, a capacitor will usually smooth it out
enough so it is much less, but if you measured that with like, a Fluke meter, then it
may very well be a sustained 370V DC.

So, this is where a "Clipper" is usually needed to keep a minimum load on the turbine
(unloaded RPMs can be hard on bearings etc) as well as keeping the voltage  below
the max turn-on voltage of the Classic 250, 200 or 150 so it will turn on.

I think the Harris unit is DC output which is a bit harder to "clip" than 3-phase AC.
We are still tweaking on our DC clippers but will hopefully have it licked soon.

Is the Harris able to be shorted or almost shorted (resistor) at the power house end ?
If so, you could use the Classic's Aux output to switch in a relay when the input voltage
goes above a certain preset value and take care of those times when batteries are
full or if the Classic somehow goes open.  It is nice to have a fail-safe though, like
what you would get with a dedicated Clipper connected up to the hydro input.

That 370 Voc .....   Is that with full open nozzles or does it change much ??

boB

[SolaRevolution]

Hi boB,
Don seems very well.  He is really helpful and curious about this.
The 370 voc was fairly steady (+/- 10v) sustained with two .5" nozzles fully open. No capacitors. There are two more nozzles (another .5" and a .375") but they need some attention so I don't have to take a shower when they are open. The Harris turbine has 3 phase output to a 2 piece rectifier bridge. There has been a lot of hacking to this system over the years. I found Don's original diagram and the existing wiring does not match, so I would have no problem with making any recommended changes.

So the clipper is not quite ready yet?  Can the Classic be used without the clipper as long as a diversion controller/load keeps the voltage down?

Alex

[boB]

So the clipper is not quite ready yet?  Can the Classic be used without the clipper as long as a diversion controller/load keeps the voltage down?

Alex

The AC (3-phase) clipper is shipping  but the DC clipper requires some more engineering.

Thanks for being willing to change things a little to make it all work.  Is the bridge rectifier
at the turbine itself of in the power house ??   Near the turbine I would guess.

Good to hear that Don is well and interested in this.  Don and I talked many years ago
about this and it has been shown with his turbine to make a huge difference in power
output by going to MPPT.   That was with the MX60 but his turbines have also been
used with the Classic.

boB

[SolaRevolution]

Yea,
The rectifier is in the turbine house, about 300' from the power room.

I'm sorry to repeat, boB, but just to be sure:
Can the Classic be used without the clipper as long as a diversion controller/load keeps the battery voltage down?

Alex

[Halfcrazy]

Yea,
The rectifier is in the turbine house, about 300' from the power room.

I'm sorry to repeat, boB, but just to be sure:
Can the Classic be used without the clipper as long as a diversion controller/load keeps the battery voltage down?

Alex

I am going to say in this case No. The Classic can go open circuit for a few reasons and if it does even for a second it will see 370vdc. This will cause damage and void the warranty. If the rectifier is in the turbine house that means you have AC present. I would install an AC clipper stand alone in the pump house and this would protect the Classic.

As for the version of firmware we will be adding that to the website today or tomorrow and usually we wait a week before putting it in production. I can get it to you as soon as you need it though and it is simple to upgrade on site.

Ryan

[SolaRevolution]

Thanks guys.

Would there be any worth while advantage to waiting for the DC clipper?

The turbine house is very damp.
The AC clipper is fairly expensive, would the DC clipper be any more affordable?

Alex

[Halfcrazy]

The DC clipper will actually be the same or more as it has more parts in it. I think the AC clipper in the turbine house is the best solution. You could put together your own voltage limiter there as well with a voltage sensing relay, a 3 phase contactor and 3 resistors. The biggest thing is just to protect the Classic from that high voltage.

Ryan