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100/250 victron 140F normal? Anyone else experience this?

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brandonboosted

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Been noticing the charger getting noticeably hot, 140F with the FLIR. Just wondering if anyone else has experienced this or what I may need to be concerned about temp wise. Panels are 320w renogy 40 voc 5S 3P. Thanks for any help.
 
My only concern is I’m over paneled by quite a bit and don’t wanna burn up mppt.
 

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A few other bits of info, the cable going to the breaker below the mppt is about the same 138F temp but after that it gets to a comfortable temperature. I’m using 2awg which should be sufficient. Also since I’m over paneled there’s about 28a that want to come through but it’s limiting to 15a which puts me right at my 100a max / 2844w.
 
That is a 250/100.

And running it at 100% max output current 140F sounds realistic.

2844W / 28V charging = 100+ amps.
It’s not “trying to pull more”. It’s running full tilt. I would adjust the SCC max charging amps to 80A and see if that cools it down. Do you really need to charge at max?
 
Given the observed temp of the cable, I would start there. It might be a bad connection. Make sure they are good and tight. I used ferrules on my welding cable going into the MPPT. The circuit breaker also looks to be a bit warm. Maybe it's part of the problem also?

You have a lot of distance between your devices. Because I installed my gear in an RV trailer, I was very constrained on space and everything was located very close together. Consider relocating the devices to shorten the cable runs. Get rid of the loop in your positive DC cable that goes to the inverter.

My math says you have 4800 watts of PV (320 watts x 15 panels). Victron says the nominal watts on a 24 volt system is only 2900 watts. I'm not going to figure out how far above 100% you are. You're way outside what I suspect Victron would consider acceptable. Assuming my math is correct.

 
I re did all my connections between the mppt to the battery I noticed this 120a breaker is the hottest part in between connections. Maybe internally there’s a sort of issue with it. Thoughts?
 
HRTKD said:
Given the observed temp of the cable, I would start there. It might be a bad connection. Make sure they are good and tight. I used ferrules on my welding cable going into the MPPT. The circuit breaker also looks to be a bit warm. Maybe it's part of the problem also?

You have a lot of distance between your devices. Because I installed my gear in an RV trailer, I was very constrained on space and everything was located very close together. Consider relocating the devices to shorten the cable runs. Get rid of the loop in your positive DC cable that goes to the inverter.

My math says you have 4800 watts of PV (320 watts x 15 panels). Victron says the nominal watts on a 24 volt system is only 2900 watts. I'm not going to figure out how far above 100% you are. You're way outside what I suspect Victron would consider acceptable. Assuming my math is correct.

Click to expand...
I have another thread where I asked about over paneling and it was determined this is within Victron specs. I like the idea of using ferrules I think I will try that. You beat me to it, I am wondering about this breaker being the issue as well now. What are you guys running in place of?
 
chrisski said:
What type of breaker is it?

Also, Victron wants multi strand wire in their SCCs. I think the intent is for set screw to flatten the wire for a better contact area and think a ferrule would defeat that.
View attachment 87210

As far as overpaneled, I use 900 watts of panels on a Victron SCC with a max output of 420 watts. The 75 volt 15 amp version.
Click to expand...
T Tocas 120 Amp Surface-Mount Circuit Breakers with Manual Reset, 12V- 48V DC, Waterproof (120A) https://www.amazon.com/dp/B07B8GWTK...t_i_D1TKSVRKYWJZ2J7QCCD1?_encoding=UTF8&psc=1
 
Good luck with that victron, I've gone thru 2 dying & have another 2 that are flakey. I'll never by that brand again. I would put a low velocity 120v fan behind it on a timer. If you have more panel power than 2900 watts, I would have that much hard wired to the charger & put the remainder on knife switches & switch them during solid overcast conditions for an extra boost or what I do is have extra panels on a solar sensor switch that kicks in & out panels according to solar intensity.
 
chrisski said:
Will speaks good of those breakers.
Click to expand...

There was another thread where a few folks thought that brand was crap. The breakers I use for higher amperage circuits are all from Blue Sea. When it comes to overcurrent protection, I don't mind paying a premium for the proven, name brand gear.

@brandonboosted, check for voltage drop on both ends of that cable and both sides of the breaker. Also, make sure the breaker really works.

Do you have a way to take out one of the parallel strings? Reducing the total watts and looking to see if the MPPT runs cooler is something to try.

I have two Victron SmartSolar MPPT 100/50. One has been in constant service for 20 months with no issues. The other is used only when my ground deployed panels are in use, which isn't very often. Neither MPPT is over-paneled.
 
I also use a T Tocas breaker and have no issue running less then 1000watts of panels thru it with a 12V system. But I would never be comfortable running what you are thru it. I’m running 1/0 welding wire and when I switch to a 24V system, I have no plans on running anything less then 1/0 wire then either. I’d start with that since there appears to be high resistance somewhere in the wires.
 
Last edited:
HRTKD said:
There was another thread where a few folks thought that brand was crap. The breakers I use for higher amperage circuits are all from Blue Sea. When it comes to overcurrent protection, I don't mind paying a premium for the proven, name brand gear.

@brandonboosted, check for voltage drop on both ends of that cable and both sides of the breaker. Also, make sure the breaker really works.

Do you have a way to take out one of the parallel strings? Reducing the total watts and looking to see if the MPPT runs cooler is something to try.

I have two Victron SmartSolar MPPT 100/50. One has been in constant service for 20 months with no issues. The other is used only when my ground deployed panels are in use, which isn't very often. Neither MPPT is over-paneled.
Click to expand...
I just placed an order for a Blue Sea breaker, I appreciate the recommendation as its hard to find quality components In this space. I have 3 strings all with separate breakers so yes I can leave only 2 on (100A) and see if that produces less heat. I think its quite interesting with the different opinions everyone has with over paneling. I had a previous thread a while back about this same topic (here) and I thought the conclusion was as long as I didn't go over my max 70A short circuit current and 250V all is well basically. I will try to test this as thorough as possible, the results may help people decide weather or not they want to risk shortening the lifespan of the controller weather or not it "can" handle the extra amperage or not.
 
Bossrox said:
Good luck with that victron, I've gone thru 2 dying & have another 2 that are flakey. I'll never by that brand again. I would put a low velocity 120v fan behind it on a timer. If you have more panel power than 2900 watts, I would have that much hard wired to the charger & put the remainder on knife switches & switch them during solid overcast conditions for an extra boost or what I do is have extra panels on a solar sensor switch that kicks in & out panels according to solar intensity.
Click to expand...
Bossrox, Please do not discard your dead Victron. I would like to do the Victron forensic study.
 
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