220 Volt Panels. How to convert to 110 AC?

[12VoltInstalls]

I'm no stranger to 220 volts but am reluctant to start dealing with voltage higher than that.

Don’t forget 220VDC can do, will and does gymnastics that 250AC won’t and doesn’t. A bad tingle on 220VAC and you’ll probably live, but DC can reach out and grab you in ways that AC usually doesn’t- and kill you better. Turning “off” solar panels can be hard even under artificial light.

 

[Symbioquine]

This is probably a bad idea, but my first thought is "what about using a custom transformer to drop the voltage down (and amperage up) by a useful ratio - say 10:1 - for each string of 5 panels before going into a 150v rated SCC?"

Maybe some EE can chime in with some insights about why that wouldn't work, would be dangerous, would wreak havoc on the MPPT tracking, etc...

 

[Bvillebob]

Transformers don't transform DC, so that doesn't work.

The other issue is that you need to be careful picking hardware to go with the system, lots of switches, circuit breakers, fuses and such are rated up to 48 volts, not for 250 volts.

 

[Symbioquine]

Transformers don't transform DC, so that doesn't work.

Doh! ?

 

[Supervstech]

Thanks again for all the replies and concerns! I'm no stranger to 220 volts but am reluctant to start dealing with voltage higher than that. All the information that has been posted shows me there are many variables involved with configuring a system. I am gong to research the products that have been recommended and study the terminology that is being discussed. My main goal at first is to put maybe 2 or 3 panels in parallel if possible and eventually have the ability to produce 110 VAC at 10 amps. I want to say that I have learned more in this forum in 24 hours than I have poking around on Google for the last 4 weeks! One surprising observation I made was that these panels appear to produce around 170V even in the shade.

You state you are no stranger to 220V, but in fact, unless you live in Europe, the voltage you think you are familiar with is 240VAC… and it is NOTHING like 220V DC very dangerous. Extreme care needs to be dealt here.

Think flaming arcs of plasma with simple mistakes…
20 panels 40+ amps when dealing with 20 panels.

Keep in mind, these panels CAN NOT BE INSTALLED ON A LIVING SPACE ROOF…
You would need grid tie micro inverters attached inside each panel to even qualify for inspection on a home…

 

[Supervstech]

Don’t forget 220VDC can do, will and does gymnastics that 250AC won’t and doesn’t. A bad tingle on 220VAC and you’ll probably live, but DC can reach out and grab you in ways that AC usually doesn’t- and kill you better. Turning “off” solar panels can be hard even under artificial light.

Oh, 240AC will do more than tingle… it’ll bite, and make you jerk or jump away…

DC won’t… it’ll bite and make you latch on and not be able to let go.

 

[Supervstech]

Of course, as a flawless electrician, I have never experienced this myself… nooo… mistakes like that never happened to me… nope.
Um… naw? No of course not… I’ve only heard stories of how it felt…

You all believe me, right?

 

[12VoltInstalls]

240AC will do more than tingle

Ya, not a minor thing. I was merely trying to contrast. So far my biggest AC jolt was 340 but it didn’t make me black out. I “missed” a half or so after my datsun 4x4coil bit me)

 

[Zil]

Yes, just how many amperes was that automotive coil? Not the same thing/

 

[Supervstech]

Yes, just how many amperes was that automotive coil? Not the same thing/

Probably around .1A... 1/10th an amp...
Could be over 100,000VOLTS though...

 

[Hedges]

Maybe 1 mA and 35kV open circuit.
In ambient air, 1500V will arc across a spark plug. At 150 PSI, higher voltage needed.

12V 1A into a transformer could produce 12 kV 1 mA, with same "on" time. But duration of spark much shorter.
Ignition coil doesn't operate as a transformer for AC, rather an inductor which stores energy in magnetic field, then releases that. It happens to have a transformer and turns ratio, so energy is put into 12V coil and released through high-voltage coil.

Measuring inductance (or current ramp rate when 12V applied) and current would let us estimate energy stored in Joules.

Threshold of life safety risk is around 1J or 10J, where 1J = 1 amp at 1 volt for 1 second.

 

[12VoltInstalls]

All I know is it gave me quite a joule

 

[HybridMoto88]

The Solar panel seem to be the FS-6440 or FS-6440A
You need an MPPT charge controller that can handle at least 250V and then you would put them in parallel with each other, each one adding 2.55 amps to the total. The total Amps cannot exceed what the charge controller can handle.
If you have the money this charge controller would work.
Victron 250V/60A
Probably overkill for your needs but it's a solid product.

After that you need some batteries for the charge controller to charge and lastly those batteries are connected to an Inverter that changes the batteries output to 120V AC.

Thank you for this, but what about the breakers? Where do those come into play? I have the exact same panels. I only want to use 2 of them. I would like to run just a 12v battery. I have the Midnight classic 250 and a midnight DC combiner along with breakers, a shunt and some surge protectors. All the breakers I have found can only hold 150v. Can I make this set up work or what do I need to do to make it work. I just want to power 2 fans through the day and have them shut off at night. I also have a 1000 watt inverter.

 

[Hedges]

With no more than 2 PV strings in parallel, fuses/breakers are not required. But breaker is useful to isolate PV so you can work on wires safely.

Non-polarized is preferred. If no more than 2 strings, or as a single disconnect after all strings (even more than 2) combined in parallel, polarized is OK.

There are some breakers rated higher than 150V. Two-pole breakers can be used in series for double the rating, so these 150V per pole breakers work for 300V. These may come pre-wired in series with a busbar, but I prefer to use one pole for positive lead, one for negative lead, so PV panel is entirely disconnected rather than leaving one lead connected.

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The second and third links are polarized breakers. Note that second link is wired in parallel, and polarity indications are the same on both breakers. It is wired in parallel to double the current. If wired in series, would double the voltage, but need current to go through the two poles in opposite directions.

The third link, polarity indications are in opposite directions. It is wired in series for double voltage. You could remove the link, put PV+ into terminal labeled +, PV- into terminal labeled minus. SCC goes to opposite end.

When PV+ goes into breaker terminal labeled (+), opposite end labeled (-) is not negative; it delivers PV+ to SCC. Double-check everything with DMM.