diy solar

diy solar

Midnight classic150 & Schneider 4024 good combo?

With Midnight standing behind the DIY series I would choose them over any other AIO unit, I have never had an issue with Midnight support and I have quite a few of their products. One issue with a whining fan in a Classic 150, my fault, I bumped it too hard in a move. Midnight support shipped me a new fan and terminal strip even though I had told them it was broken by myself. Two Classics, Two Kid controllers, Two Combiners, 8 big baby boxes for MNPV and MNAC breakers , e-panel for Magnasine, 3 SPD lightning arrestors DC-15 DC control center, whizbang jr,s .Everything is very well designed for the job at hand and works very well in practice.

Midnight gear is more expensive than offshore, but zero fails in too many years too count, Im long out of warranty by now and Im not worried at all, its just very well designed gear designed for very high reliability

Pretty much of the rest of my solar gear is Tier 1 as another member puts it.

Only one power outage in 20 years....blew a inverter...two breakers flipped , power back on.
Nice. Yeah I need lightening arresters
 
Nice. Yeah I need lightening arresters
If sky sparks do visit you , then yes you do need sky spark arrestors, Aluminum framed Solar Panels are pretty good sky spark attractors. I have one on each Solar Controller input and one on the inverter output buss, Inverters are never operated at the same time but they do share the same AC Buss. I will probably buy another so I have one right at each inverter.

Midnight SPD’s are some of the best “sky spark arrestors“
 
The maximum rating does depend on the “voltage transform ratio” That is the ratio between the battery voltage and the input voltage from the array. For those folks who just must use the highest voltage possible for the P.V. input voltage will have lower current rating directly due to the fact that the higher the “voltage transform ratio” the less efficient the DC to DC converter in the front end of the SCC. That reduced effeciency results in increased heat in the controllers, nessecating derating of the current capability of the controller. This is very clearly shown in Midnight’s graph above.

In my systems I use the lowest ”voltage transform ratio” possible. Im using mostly 72 cell panels wired 2S for an input voltage of 70 volts for a “voltage transform ratio“ of 2.3 so I have a limit of 94 amps , 2700 watts but if I wired 3S I would have a voltage at input of 105 volts resulting in a “voltage transform ratio” of 3.65 resulting in far more heat being generated by the SCC directly resulting in the lower current rating of 82 amps and 2553 watts.


As shown clearly in Midnight’s graph above My controllers can do 2700 watts at 24 volt battery but if i wired 3S my maximum power would be 2553 watts with the same panels and Controllers.

I also use Sanyo/Panasonic multilayer panels which have an amorphic layer of polycrystalline cells on top of monocrystalline cells which have an unusually high MPP of 53.5 volts which I run all in parallel....i.e. 1S for a voltage transform ratio of 1.85 which allows me to run at 96 amps , 2700 watts, but if I use those same panels wired 2S I would have a voltage input of 107 volts, and a “voltage transform ratio” of 3.7 resulting in current derating to 82 amps, power to 2553 watts.

The disavantage of running a lower “voltage transform ratio” I spend more on hardware, but the advantage is more power and far longer system life.....

The situation is far, far worse with an array voltage of 350-500 volts...to charge a battery.....that is really a false economy...you save a few bucks on combiners and hardware but you tax the electronics far harder, you will never get the life out of such a system as compared to a very conservative design using far more conservative configurations.

Now with a straight grid tie system the voltage input of the controller does need to above the Peak to Peak voltage of the AC output voltage for best efficiency. That is where a 360-600 volt array is useful, certainly not with any battery based systems....

I do realize that this post will fly right over the heads of many readers but I am posting this as very many persons do not realize the effects of heat on electronics gear and have never considered the “voltage transform ratio”

Now ask me again how I have had no system fails in 20 years.....

You can buy the worlds‘s best stereo power amplifier but if you run it at full power all the time you will cook it....
Heat is the enemy of electronics.
 
The maximum rating does depend on the “voltage transform ratio” That is the ratio between the battery voltage and the input voltage from the array. For those folks who just must use the highest voltage possible for the P.V. input voltage will have lower current rating directly due to the fact that the higher the “voltage transform ratio” the less efficient the DC to DC converter in the front end of the SCC. That reduced effeciency results in increased heat in the controllers, nessecating derating of the current capability of the controller. This is very clearly shown in Midnight’s graph above.
.... When you have a battery voltage of 48v compared to 12v for a given array voltage, the voltage transform ratio is much lower, and yet the current limit still is smaller. How am I mixed up here?
 
The current flowing through the controller is multiplied by the voltage it is operating at, Its the total power that counts,
 
If sky sparks do visit you , then yes you do need sky spark arrestors,
By "visit" do you mean "in the neighborhood" or "a direct hit to the array"? I did not think a spark arrestor would help much with a direct lightening strike.
 
The maximum rating does depend on the “voltage transform ratio” That is the ratio between the battery voltage and the input voltage from the array. For those folks who just must use the highest voltage possible for the P.V. input voltage will have lower current rating directly due to the fact that the higher the “voltage transform ratio” the less efficient the DC to DC converter in the front end of the SCC. That reduced effeciency results in increased heat in the controllers, nessecating derating of the current capability of the controller. This is very clearly shown in Midnight’s graph above.

In my systems I use the lowest ”voltage transform ratio” possible. Im using mostly 72 cell panels wired 2S for an input voltage of 70 volts for a “voltage transform ratio“ of 2.3 so I have a limit of 94 amps , 2700 watts but if I wired 3S I would have a voltage at input of 105 volts resulting in a “voltage transform ratio” of 3.65 resulting in far more heat being generated by the SCC directly resulting in the lower current rating of 82 amps and 2553 watts.


As shown clearly in Midnight’s graph above My controllers can do 2700 watts at 24 volt battery but if i wired 3S my maximum power would be 2553 watts with the same panels and Controllers.

I also use Sanyo/Panasonic multilayer panels which have an amorphic layer of polycrystalline cells on top of monocrystalline cells which have an unusually high MPP of 53.5 volts which I run all in parallel....i.e. 1S for a voltage transform ratio of 1.85 which allows me to run at 96 amps , 2700 watts, but if I use those same panels wired 2S I would have a voltage input of 107 volts, and a “voltage transform ratio” of 3.7 resulting in current derating to 82 amps, power to 2553 watts.

The disavantage of running a lower “voltage transform ratio” I spend more on hardware, but the advantage is more power and far longer system life.....

The situation is far, far worse with an array voltage of 350-500 volts...to charge a battery.....that is really a false economy...you save a few bucks on combiners and hardware but you tax the electronics far harder, you will never get the life out of such a system as compared to a very conservative design using far more conservative configurations.

Now with a straight grid tie system the voltage input of the controller does need to above the Peak to Peak voltage of the AC output voltage for best efficiency. That is where a 360-600 volt array is useful, certainly not with any battery based systems....

I do realize that this post will fly right over the heads of many readers but I am posting this as very many persons do not realize the effects of heat on electronics gear and have never considered the “voltage transform ratio”

Now ask me again how I have had no system fails in 20 years.....

You can buy the worlds‘s best stereo power amplifier but if you run it at full power all the time you will cook it....
Heat is the enemy of electronics.
what would you consider excessive heat in a Midnite Solar Classic charge controller? (in C)
 
The maximum rating does depend on the “voltage transform ratio” That is the ratio between the battery voltage and the input voltage from the array. For those folks who just must use the highest voltage possible for the P.V. input voltage will have lower current rating directly due to the fact that the higher the “voltage transform ratio” the less efficient the DC to DC converter in the front end of the SCC. That reduced effeciency results in increased heat in the controllers, nessecating derating of the current capability of the controller. This is very clearly shown in Midnight’s graph above.

In my systems I use the lowest ”voltage transform ratio” possible. Im using mostly 72 cell panels wired 2S for an input voltage of 70 volts for a “voltage transform ratio“ of 2.3 so I have a limit of 94 amps , 2700 watts but if I wired 3S I would have a voltage at input of 105 volts resulting in a “voltage transform ratio” of 3.65 resulting in far more heat being generated by the SCC directly resulting in the lower current rating of 82 amps and 2553 watts.


As shown clearly in Midnight’s graph above My controllers can do 2700 watts at 24 volt battery but if i wired 3S my maximum power would be 2553 watts with the same panels and Controllers.

I also use Sanyo/Panasonic multilayer panels which have an amorphic layer of polycrystalline cells on top of monocrystalline cells which have an unusually high MPP of 53.5 volts which I run all in parallel....i.e. 1S for a voltage transform ratio of 1.85 which allows me to run at 96 amps , 2700 watts, but if I use those same panels wired 2S I would have a voltage input of 107 volts, and a “voltage transform ratio” of 3.7 resulting in current derating to 82 amps, power to 2553 watts.

The disavantage of running a lower “voltage transform ratio” I spend more on hardware, but the advantage is more power and far longer system life.....

The situation is far, far worse with an array voltage of 350-500 volts...to charge a battery.....that is really a false economy...you save a few bucks on combiners and hardware but you tax the electronics far harder, you will never get the life out of such a system as compared to a very conservative design using far more conservative configurations.

Now with a straight grid tie system the voltage input of the controller does need to above the Peak to Peak voltage of the AC output voltage for best efficiency. That is where a 360-600 volt array is useful, certainly not with any battery based systems....

I do realize that this post will fly right over the heads of many readers but I am posting this as very many persons do not realize the effects of heat on electronics gear and have never considered the “voltage transform ratio”

Now ask me again how I have had no system fails in 20 years.....

You can buy the worlds‘s best stereo power amplifier but if you run it at full power all the time you will cook it....
Heat is the enemy of electronics.
Makes perfect sense in longevity of a product not just in solar but in vehicles tools and anything in that nature. Yeah I drive a semi for a personal vehicle to haul stuff a pickup could possibly haul but if I don't load it up to max 80,000 lbs it will last me for decades. Before one gets on the price I paid for one plus insurance/registration and fuel costs I will say I only paid $5250 for it, insurance $93 month registration $150 and I get around 12 mpg until I hitch a trailer up around 8 mpg and registered up to 50,000 lbs. What pickup truck you you know can haul 50k lbs for that price and last long, none
 
what would you consider excessive heat in a Midnite Solar Classic charge controller? (in C)
MrM1,

I saw your post, wanted to respond, but s##t happens. In reality I would like to operate at 50 deg C but my upper limit is 70 deg C , after that I feel that I am taxing my hardware too hard, I think about buying more hardware.

I have a stack of gorgeous Carver Audio gear that is 25-30 y.o. Works perfectly, Run the power amp at 30% capacity, If I really need to peel the paint off the wall, I switch from my 100 watt Carver power amp to the M-500 which will rip your ears right off. Never had a fail due to high temp, same thing, I never let it approach 70 deg. C

I did have an event where my two kids were running at 92-95 deg C when suddenly we went from cold, foggy to bright and hot. I zoomed back to home base and the kids were too hot to touch, shut them down for a rest and powered up different arrays feeding stone antique Trace C-40 PWM controllers that just refuse to die. They were designed by the same team at Midnight Solar.

I was over paneling and using a high voltage transform ratio 113 volts in to 28 volts battery. The kids survived well, but I really do not need to do that as I have far more array’s than I need on sunny days.

One of my problems here is very unpredictable weather as I am not far from that big blue pond, the Pacific Ocean, one minute, chilly, cold pea soup fog, within 15 minutes full sun, and Im setup for pea soup....
 
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