HOU_Castle
Learning Everyday....
That was I thought too. The fuse type has time delay built in to it.
Do NOT discard a Dead Victron MPPT 100/30 or its kind
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HOU_Castle
Learning Everyday....
As long as the total panels of voltage and or current meet the spec limit you will be okay. Victron design seems to provide more fuse amp protection, but can't control the weather and ambient temperature, such as strange cold snap in New Orleans (28F and sunny). Perhaps, 20 years once?
What usually kills one is heat.
Overpabeling too far forces max current for too long a duration, and the heat cannot be dissipated.
Adding a fan, to help the heat dissipate will extend its life...
Installing a larger fuse is foolish.
Overpabeling too far forces max current for too long a duration, and the heat cannot be dissipated.
Adding a fan, to help the heat dissipate will extend its life...
Installing a larger fuse is foolish.
The whole point for me of using a 75/15 and not a 100/30 is the smaller footprint without the extra bulk of a heat sink. I want to run three 100W panels in series (optimum 17.7V & 5.7A) which the 75/15 on very sunny days will convert to a solid output of 15A and discard the rest.
I read on the forum about someone using a setup like this and assumed I wouldn’t have a problem. I guess the only way to know if the Victron will heat up too much is to try.....unless someone else already has.... ?
I read on the forum about someone using a setup like this and assumed I wouldn’t have a problem. I guess the only way to know if the Victron will heat up too much is to try.....unless someone else already has.... ?
efficientPV
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Thanks for letting me know never to buy one of these broken charge controllers. While I could fix it, I could never deal with a cobbed up front panel.
Agreed but he just replaced the internal 50 amp fuse with an external 50 amp fuse.
Am I missing something? Always a possibility ?.
HOU_Castle
Learning Everyday....
True, I just replaced it with same 50A fuse. The different is this time the fuse location is outside.
It seems to me there are 3 things that can push these Victrons to blow the fuse:
[1] accidentally reverse the polarity while panels are providing a lot of power
[2] input a voltage from panels only slightly above the rating (maybe 105V on a 100/30 or 78V on a 75/15?)
[3] Over-panel the Victron so the output current is way above the rating. Since the Victron is having to discard the extra amps the panels may be feeding it (above 30A on a 100/30 or above 15A on 75/15) it could produce too much heat.
It is difficult to determine how much you can over-panel safely because it’s hard to guess how much heat will be produced in each situation.
My 75/15 is rated for 220W at 12V so it’s really designed for 2 100W panels. I (think I) feel comfortable over-paneling to 3 100W panels. This means that on a cool sunny day it could produce 20+ amps and generate A LOT of “fuse blowing, capacitor cooking” heat because it is designed to dispose of everything over 15 amps.
[1] accidentally reverse the polarity while panels are providing a lot of power
[2] input a voltage from panels only slightly above the rating (maybe 105V on a 100/30 or 78V on a 75/15?)
[3] Over-panel the Victron so the output current is way above the rating. Since the Victron is having to discard the extra amps the panels may be feeding it (above 30A on a 100/30 or above 15A on 75/15) it could produce too much heat.
It is difficult to determine how much you can over-panel safely because it’s hard to guess how much heat will be produced in each situation.
My 75/15 is rated for 220W at 12V so it’s really designed for 2 100W panels. I (think I) feel comfortable over-paneling to 3 100W panels. This means that on a cool sunny day it could produce 20+ amps and generate A LOT of “fuse blowing, capacitor cooking” heat because it is designed to dispose of everything over 15 amps.
Sun,
answers 1 and 3 are correct, over voltage will not blow the fuse by itself, it will blow out the front end of the charge controller, almost always fatally. Most fuse failures are due to overpanelling. The one big mistake that a lotta newcomers is overpaneling and running the Voltage in near the maximum. both lead to too much heat and heat is the enemy of electronics, you can buy a very high end stereo amplifier but if you run it at maximum volume it will fail quickly. If you run it at a comfortable volume it will last years....
if your controller is rated 600 watts, run it at 400 watts for a long life and reliability
David
answers 1 and 3 are correct, over voltage will not blow the fuse by itself, it will blow out the front end of the charge controller, almost always fatally. Most fuse failures are due to overpanelling. The one big mistake that a lotta newcomers is overpaneling and running the Voltage in near the maximum. both lead to too much heat and heat is the enemy of electronics, you can buy a very high end stereo amplifier but if you run it at maximum volume it will fail quickly. If you run it at a comfortable volume it will last years....
if your controller is rated 600 watts, run it at 400 watts for a long life and reliability
David
Hello all. Very interesting discussion. I have had the same situation on 3 controllers and all three simultaneously allowed smoke to escape at the same time. They were the 100/50 models, and were the Chinese version made by Fanguspan. Before you jump in and say "ah ha! Made in China, eh?", please listen to what caused them to blow. It was all my fault. I wanted to switch the dial to another battery setting because I was experimenting on which was best suited to my LiFo batteries. I shut off all the circuit breakers leading into the 3 controllers and then turned off the battery switch. Somehow, I got distracted when turning it all back on, and turned on the solar panel breakers first, before the batteries. Some have told me that theirs have survived a brief mistake like that, while others like me haven't been so lucky. I have 3900 watts of panels on board my boat, and when this happened I was in full sun, so maximum power was coming to each SSC. The smoke was quite quick to appear! However, I was too late in getting the panel breakers off, and had no working SSC's any more. Being a packrat, I didn't toss them away, and I am happy to come upon this article and what happened inside the boxe. I am not sure my fuses went, but now I will give one the surgery and look. Thanks for the pictures, so I know where to make the incision. (I did try to rip one apart, but it was stronger than I, and that blue plastic didn't tear no matter how hard I tried.) Today the setup has the Victron 250/70 and the 150/85. Of note, the newer ones have provisions for a remote switch that somehow can turn off the SSC WITHOUT closing off any power coming from the panels, or circuit breakers in my case. Why the fuse, if there is one, doesn't pop, is a mystery. However it works great, and I use the 250/70 relay to control possible over voltage on the 150/85 by just turning it off. (The LCD panel can no longer be read and therefore I cannot change any setting manually). Also, the 250/70 with its blue tooth capability, I can now change any parameter I want, including the relay, and what parameters (like high volts) I want to activate it. I will let everyone know what I find inside the box after it comes off the operating table. I seem to remember the smoke coming from the other side of the box, but also at the bottom. But then again, when smoke is coming out, who is taking notes? Further details: The solar panel feed wires go into a box near the SSC's and run thru 3 separate 400VDC miniature circuit breakers, 20amp, 16A and 10A, which break both the positive and negative wires. My lithium bank is 800ahr wired at 24v. Cheers
HOU_Castle
Learning Everyday....
It is not simple to separate the blue stuff. It took me half day just to separate the blue tuff from the case. Keep me update if you are successfully fixed the Victron.
I have 5000 watts of panels at 24v on a 250/100, so ~2x the rating of the charge controller. Right or wrong it's been working great for years without issue. Actually hoping to get another row of panels added before winter, so it will be 2.5x the rating if I can manage to get it done before it gets cold.
I believe the Victron stuff is smart enough to current limit, but don't recall if that is specifically mentioned in the manual or not. You can watch this on partially cloudy days, go from discharging to right at 100 amps charge in a couple seconds.
It does specifically mention in spec sheet the max Voc which for the 250/85 and 250/100 is 70A so you are not technically over the rating. Here is detailed blog post showing how to calculate how much you can overpanel with the Victron controllers: https://www.victronenergy.com/blog/...ar-modules-to-the-new-mppt-charge-regulators/
How can max Voc be 70A? Voc is in volts, not amps. The max Voc of a Victron 250/XX is 250V.
Sorry, am really tired
it is the short circuit current of the panels.
efficientPV
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I don't think fuses make smoke. This is more likely a bigger adventure.
RobertGreen
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When you guys are talking about "overpaneling" in this context, do you mean adding solar array capacity that exceeds the maximum input short circuit current rating of the charge controller (the Isc rating)?? Or just configuring an array whose maximum output exceeds the maximum charging power of the device?
The latter case, as long as you're still within the Voc and Isc limits for the device, is claimed to be safe and warranted for long term use by the manufacturer. After all, how is this type of "overpaneling" going to create more heat? the controller will only provide up to it's maximum charging current to the battery. Victron claims that oversizing the array (exceeding Isc limit) can be harmful in several ways.
My understanding:
-If the output voltage of the panels ever exceeds the input voltage rating of the controller, the controller can be fried fairly easily. A Victron 100|50 that is fed 105V from the panels will likely blow the fuse (or the front end of the controller) since it is only rated to handle 100V. Also, if the panels are feeding the controller a lot of power and there is no load connected to the controller (such as a battery), the fuse (or another component) will likely blow.
-The volts & amps created by the panels and fed to the controller are converted by the controller to {approximately} 12V (or 24V) and corresponding amps. For example, panels that output 48V and 15A may be converted to 12V and 59A. A Victron 100|50 is designed to output up to 50 amps. It will actually limit its output to the battery only up to 50 amps, so the entire 59 amps won't make it to battery. In this example the controller is being asked to handle outputting more current than it is rated for, so it will get very hot and could burn up. It can probably handle the heat generated by the 59 amps but not much more. Supervstech (above) suggested that adding a fan to the controller's heat sink may prevent it from burning up and also extend its life.
In summary, "overpaneling" means using an excess of solar panels whose total output exceeds the specs for the controller.
This can be OK and may work well but: (a) voltage input into the controller that is too high will blow the fuse (or another component), and (b) current output by the controller that is too high creates a lot of heat that can burn it up.
-If the output voltage of the panels ever exceeds the input voltage rating of the controller, the controller can be fried fairly easily. A Victron 100|50 that is fed 105V from the panels will likely blow the fuse (or the front end of the controller) since it is only rated to handle 100V. Also, if the panels are feeding the controller a lot of power and there is no load connected to the controller (such as a battery), the fuse (or another component) will likely blow.
-The volts & amps created by the panels and fed to the controller are converted by the controller to {approximately} 12V (or 24V) and corresponding amps. For example, panels that output 48V and 15A may be converted to 12V and 59A. A Victron 100|50 is designed to output up to 50 amps. It will actually limit its output to the battery only up to 50 amps, so the entire 59 amps won't make it to battery. In this example the controller is being asked to handle outputting more current than it is rated for, so it will get very hot and could burn up. It can probably handle the heat generated by the 59 amps but not much more. Supervstech (above) suggested that adding a fan to the controller's heat sink may prevent it from burning up and also extend its life.
In summary, "overpaneling" means using an excess of solar panels whose total output exceeds the specs for the controller.
This can be OK and may work well but: (a) voltage input into the controller that is too high will blow the fuse (or another component), and (b) current output by the controller that is too high creates a lot of heat that can burn it up.
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ericjanvanputten
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Interesting thought.
I was planning on putting 3 panels on a 100/50 to size to real world output and not oversize the MPPT, now I'm not so sure as the MPPT output limit will probably be hit regularly, input limit's not. What do you guys think?
Panels (they will live on a boat so not optimal angles, etcetc):
- 355Wp STC
- 265Wp NOCT
- Voc 39.8V
- Isc 11.52A
Controller being the 100/50 at 12 volt, the Voc & Isc are well within limits (100v & 60amp) , but the MPPT output of 700 watts will probably regularly be hit.
Reasons for the 100/50 with 3 panels:
- sized to real world situation (I think)
- physical size of the 100/50
- reducing complexity & cost for the future when more strings are added.
(ps. first post here)
3. ”Discard the extra amps” is wrong idea. Controller doesn’t discard the extra amps, it uses only what is needed for charging the battery.
100v 50A panel on 12 system and 50A MPTT is not going to result in 50 Amps drawn from panel. Something like 700W Max to battery and controller draws only little over 7 amps from panels.
Reasons behind the max input current limit are bit more complicated and not necessarily that obvious.
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