I have a liveaboard sailing catamaran.
It has 500W of solar through my spankin' new Classic 150, and a whopping great 150A Balmar alternator with an MC614 smart charge regulator on one of the two engines.
When sailing, the engine is off and the Classic will happily do it's stuff. However if I happen to have the engine running, the Balmar has the capability of generating up to 150A, but the smart charge regulator may not operate effectively because it will see the higher charge voltage from the Classic, and so the output power of the alternator may be reduced.
I need a way to automatically stop the Classic from producing power when the engine is running. I *COULD* whack a relay into the PV input line and interrupt supply, but it would have to be a biggie.
I'm wondering if there are any smarts in the Classic that could do this?
The classic has a logic input on Aux2 that will stop it from charging. There is a logic high and a logic low mode. I will dig up the specs but basically it was geared around 12v. So in one state you apply 12v and it stops charging in the other you remove 12v and it stops charging. You could run a switched 12v lead from the motor to Aux2 and that way anytime the motor is running the classic would rest.
Ryan
That sounds ideal Ryan. I did read the manual, but I could not find a lot on inputs.
(Would the use of this method mean I could not use a Wizbang?)
Yes at this time. The Aux2 is the only Logic Input
The manual is being revamped now. There may be nothing about this particular Aux 2 mode in there.
Yes, unfortunately if the Aux 2 is being used for a WB Jr. then it cannot be used for a disable input.
dang !
However, you might be able to do some kind of communications thing to turn it on and off via
Ethernet ?
boB
Monkey men all in business suits
Ethernet is probably adding too much complexity. I don't think I can convince my 30Hp Yanmar diesel to start spitting out packets.
I think the Wizbang has a lot to offer so I'll try to retain that capability.
What about a high-ampere NC contactor with a 12V drive coil driven by a signal from the engine when it's running. Engine on = contactor energised = PV array disconnected. (Resistor-capacitor across the contacts to quench the spark). GXNC14B would do the trick, but a quick google has not found a supplier here in Oz yet.
That would leave the Classic's AUX2 free for the Wizbang.
(Or... I am an electronics engineer so if there is somewhere on the PCB I could tap into to force the Classic into off mode then happy to go down that path and save the cost of the contactor)
---------------------
boB... Teachers and critics all dance the poot.
Nah, get yourself a 1w computer, with gpio, listens to generator, tells the classic over modbus/tcp to hold up. Side effect... all the system monitoring youll ever want or need.
Quote from: zoneblue on October 14, 2013, 02:19:00 PM
Nah, get yourself a 1w computer, with gpio, listens to generator, tells the classic over modbus/tcp to hold up. Side effect... all the system monitoring youll ever want or need.
Anything that can go wrong, will go wrong at sea. I want this simple, robust, and bulletproof.
I can source the GXNC14 from the USA for $155 (+$65 freight.. damn it!) straight from Gigavac. Pricey but quality product.
I know what you mean about mobile computers, i have one in a motorhome. For a long while i had trouble with the thing rebooting going over large bumps. Solder a bunch of caps across the dc rails helps. Minimize anything with cards, or on board physical connectors, eg ram, mini pci etc.
>What about a high-ampere NC contactor with a 12V drive coil driven by a signal from
> the engine when it's running. Engine on = contactor energised = PV array disconnected.
Just where exactly are you planning on putting that relay. I hope not series to the array as implied above. Have you seen the size of the arc those things produce. If you stick it series to the controller, more problems acrue because now you have pv live to array, and no battery. 'Nobatt' condition. Also not good.
What choices are left... Actually i woudnt stress about it. Bob said a while back that both aux1 and aux2 will eventually be PWM/input etc. Correct me if im wrong. And theres also WB senior which theyve only hinted at but i get the impression is a external aux hub type a thing. Something like outback hub? Fishing here...
Quote from: DevoDave on October 14, 2013, 05:27:02 AM
What about a high-ampere NC contactor with a 12V drive coil driven by a signal from the engine when it's running. Engine on = contactor energised = PV array disconnected. (Resistor-capacitor across the contacts to quench the spark). GXNC14B would do the trick, but a quick google has not found a supplier here in Oz yet.
I see you have four 135watt PVs, you haven't said how they are wired to the Classic, all four in parallel or two strings of two in series?
I would not go the large contactor way to switch out the panels, instead I would use a separate SSR, 10amp, 100v type to switch out each panel or each series string. These are NO but your application would need NC. For that a simple transistor/2 resistor NOT gate with input from the engine (12v) would make SSRs go Open and hence disconnect PVs from Classic. When engine stops they reconnect.
Low cost too, cheap SSRs on Ebay, see wiki for NOT gate design, I seem to remember a SAINSMART ready made pcb with SSRs for a few $
Just my thoughts...
dgd
Panels will be one series string. Voc is 22V per panel giving me 88V total, Isc is 8A. Given the panels are on a mobile platform (yacht) with varying orientation to the sun, and the additional complexity of shade from the sails I should think series is my only choice.
I considered SSR's, but again in the interest of robustness I discounted them. It's very difficult for a mechanical NC contactor to fail with the contacts left in an open-circuit state. I was going to put the the contactor in series with the array, and had given thought to the arcing issue by selecting a contactor that might mitigate the issue. The switching chamber is a vacuum so there is no air to turn to plasma, and it's rated to 300,000 operations with the expected load.
However, in saying all that if boB is able to suggest that AUX1 may become an input in the near future, I'll happily hold off for a bit.
Whaddayasay boB?
Quote from: DevoDave on October 15, 2013, 05:19:22 AM
Panels will be one series string. Voc is 22V per panel giving me 88V total, Isc is 8A. Given the panels are on a mobile platform (yacht) with varying orientation to the sun, and the additional complexity of shade from the sails I should think series is my only choice.
I considered SSR's, but again in the interest of robustness I discounted them. It's very difficult for a mechanical NC contactor to fail with the contacts left in an open-circuit state. I was going to put the the contactor in series with the array, and had given thought to the arcing issue by selecting a contactor that might mitigate the issue. The switching chamber is a vacuum so there is no air to turn to plasma, and it's rated to 300,000 operations with the expected load.
However, in saying all that if boB is able to suggest that AUX1 may become an input in the near future, I'll happily hold off for a bit.
Whaddayasay boB?
Unfortunately, making AUX1 able to be an input would require a hardware change as well as software so I don't see that happening
anytime soon on the Classic. Yes, I ~shoulda~ ~coulda~ ~woulda~ done that originally but it's kind of late if compatibility with older Classics is going to be maintained. Also, since it would require a PCB change and some change to the circuitry, there is just no room left on the PCB for much of anything.
Sorry I can't give you more positive "input" on this.
boB
Quote from: DevoDave on October 12, 2013, 07:33:01 AM
I need a way to automatically stop the Classic from producing power when the engine is running. I *COULD* whack a relay into the PV input line and interrupt supply, but it would have to be a biggie.
DD
Ok, after re-reading this thread I don't quite understand where there would be confusion with multiple charging sources to one battery bank?
Multiple charging sources is, at least from my experience, quite common. Can I ask where you may see this as a problem in your setup?
When your engine is charging the bank then the Classic will still go through its bulk, absorb, float cycle and eventually stop sending PV power to the bank when its full.
Maybe I'm missing something here but contactor or ssr switching out the PV array doesn't seem to be necessary.
Again just IMHO
dgd
Dave;
I have to agree with dgd here.
It sure seems you are concerned over a non issue. Perhaps I misunderstand your concern?
I know of many many systems with multiple charge sources, including my own, and all seem to work fine with no special modifications.
To be blunt and to the point you seem to be over thinking the plumbing here?
Good luck with it.
Tom
I would welcome ANY input from the pv. The diesel alternator reducing its output is a good thing, every watt you take from that alternator costs you more diesel, and last i checked, diesel here is $4.29/gallon and the photons are still free.
Hi guys,
In response to recent posts, my concern is that the Balmar/MC614 may stop outputting it's up to 150A (1800W) because it sees the charge voltage from the PV/Midnite (500W max) and assumes that the batteries have a higher SOC than they actually have.
This might happen at stages 4,7, and 9 below.
QuoteRegulator Operation
The MC-614 regulator’s microprocessor controlled charging system uses a sophisticated, multi-stage profile to deliver
maximum charging output, while protecting the batteries from overcharging damage. When the regulator is first turned on,
the processor performs a quick one-second self diagnostic assessment. Following that diagnostic, the MC-614 initiates a
charge program as follows:
1. Start Delay - Factory set at one second. Can be user-adjusted to a maximum of 999 seconds in the regulator’s advanced
programming mode. See Advanced Programming section for adjustment instructions.
2. Soft Ramp - Gently increases voltage to bulk preset levels based on battery program selected.
3. Bulk Charge - The most aggressive of the charging stages. Voltage is held at a pre-set level, specified by battery
program selected, for a set time period. Factory-set bulk time is 18 minutes. Adjustable in 6-minute increments.
4. Calculated Bulk Charge - Holds voltage at bulk level for six minutes, then calculates battery condition by comparing
existing voltage, time at voltage, and field percentage to target values. If values are met, the regulator advances to
the next stage. If values are not met, the regulator continues to bulk charge and compares real-time to target values.
This will re-occur until all values are met.
5. Ramps down to Absorption voltage.
6. Absorption Charge - Regulator continues to control the alternator’s output voltage for an additional 18 minutes at
approximately 2/10’s of a volt below bulk charging voltage. Adjustable in 6-minute increments.
7. Calculated Absorption Charge - Holds voltage at absorption level for six minutes, then calculates battery condition
bycomparing existing voltage, time at voltage, and field percentage to target values. If values are met, the regulator
advances to the next stage. If values are not met, the regulator extends the absorption charge and compares realtime
to target values. This will re-occur until all values are met.
8. Ramp down to Float.
9. Float Charge - Regulator continues to control the alternator’s output voltage for an additional 18 minutes, typically
at a volt less than bulk voltage (based on battery program presets). After that initial fixed time period, the regulator
can respond to increased charging demand by cycling to absorption voltage. After 12 hours of continuous operation,
the regulator will automatically revert to absorption voltage through calculated absorption and back to float charging
stage.
Am I barking up the wrong tree?
Dave,
The alternator controller appears to just go through the normal Bulk, Absorb and Float cycles. I assume you can configure the Absorb and
Float voltage set points? I would just make these the same as those for the Classic or perhaps even set the Classic slightly higher to maximise the PV power usage while reducing diesel use (I think I have the logic the right way around :D )
I would not expect any issues of confusion to occur.
I was also intrigued by your making the PVs into one serial string because of shading issues. I don't know much about the effects of partial array shading but I imagine that serious shading on even one panel of the string would seriously drop the power, voltage and current.
My thinking is that the four panels set up as two strings of two (since they are nominal 12v panels and your battery is 24v) would provide more power if one string was shaded but the other was seeing full sunlight.
I may be (probably am) completely wrong with this but it may be worth trying if you can readjust the panel wiring for 2 strings of 2 panels.
dgd
dgd,
Your question prompted me to dive into the advanced options on the MC614 charging regulator. I *HAD* thought that the only programming available was to set the chemistry of the batteries. (I have 2x200Ah AGM's in parallel for a 12V system BTW.)
I have found that I can in fact amend the Bulk, Absortion, and Float voltages! The options are buried behind password protection, and programming consists of using a magnet to trigger a reed switch buried inside the epoxied device observing a 3 letter 8-segment display. May be an arduous operation.
So, (thanks to your suggestions) it looks like I just need to tweak settings between the Midnite and the MC614 to ensue that they are not fighting. Thanks!! That'll save me some cash.
As far as the shading issue on the PV panels goes, I can easily make the system 1 string of 4, 2 strings of 2, or 4 strings of 1 if need be. The solar panels are all within a couple of metres of each other, and the Midnite is only 4 metres cable run from any of them.
Considered wisdom in the boating fraternity varies widely, with the gold-standard suggestion being an MPPT for EACH panel. Shading on a boat is not considered to be the same as shading on a rooftop. It will vary as the boat swings with wind/water and will have solid items like the mast and boom (with sailbag/sail) casting quite dark shadows. Another factor is that all the panels will be flat-mounted.. reducing efficiency.
With modern panels and decent MPPT's (like the Midnite) I have seen a lot of people say that series connection with a panel-bypass diode on each panel is a good solution.
I'm probably going to have to suck-it-and-see to determine the most efficient wiring configuration with my panel positioning and yacht behavior. Very willing to hear of real-world experience if anyone has been doing a lot of marine work?