First Time Solar Setup - Need Your Opinions!

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Comments

  • ChevyNo1ChevyNo1 Solar Expert Posts: 30
    Re: First Time Solar Setup - Need Your Opinions!
    Awesome man! Very best of luck with your off grid plans. I could now easily cut the grid wires, but as I'm getting older, I figured it best to keep them there as backup.
    For all intents and purposes, I am off grid. Use extremely little grid power and what I do use, is definitely NOT a necessity. When I get that second full size freezer emptied (Yeah, I have 2 full freezers) I won't be using any power from the grid. One of these days I'm just going to empty out the second one out and pull it's plug. I keep putting it off.
    Hopefully your wife will see the awesome beauty that Winter can bring, and not just the negative :)
    Would be awesome if your new place had a reliable brook nearby that you could tap into for micro hydro. Mine only puts out 135 watts, but it keeps the batteries full up on charge throughout the night and heavy overcast days, and I use all I want, just don't waste any. Never did waste, so no big change in lifestyle needed. Any heavy loads are saved for sunny days (or hours). Living with nature, not fighting it. Appreciating more every day, that I'm in a position, energy wise, that once was beyond my wildest dreams. Never thought I'd progress so far with it. Now I never want to go back!
    Totally dark outside, the sun's been gone for almost 4 hours, and all the following are on and running: Fridge(converter freezer), full sized freezer, TV, outside lights, inside lights. air exchanger, and this laptop, all running off my system (wired fridge and freezer so they don't run at the same time) and battery voltage is holding at 13.2, Gotta love that! :p

    Yea for me my new place is at least a half-mile away from the nearest pole - from what I understand the costs are crazy to bring it in. So I won't have a choice :D

    We actually do get some snow here in the winter (mountains northeast of Phx) - so it's been a good stepping stone between Phoenix and the NW. I am pretty sure she'll do OK except for the really cold days ;)

    Nice setup you have going there. I have been quite excited about this whole thing and getting things moving. I wish I knew if we would be staying and I would do this a bit differently - I know I'm not going about this the optimal way, just trying to make it work with potentially short term use.
  • ChevyNo1ChevyNo1 Solar Expert Posts: 30
    Re: First Time Solar Setup - Need Your Opinions!
    mike90045 wrote: »
    Right. or you may get a lot of smoke. We have no way to tell what you will buy, how it is made, and where the grounds in your system are. And sometimes the best stuff is wired such that you could not do this without letting all the internal smoke out. :cry:

    OK - so by breaking the 24V bank into 2x12 - would that make this potential issue go away? Or still a risk? The only connection between the two systems would be the two chargers running off the same genset.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: First Time Solar Setup - Need Your Opinions!
    ChevyNo1 wrote: »
    OK now this confuses me - are you saying that if I have a 24V battery bank - that I can hook up two 12V chargers and it will charge at 24V? Is that because technically by hooking chargers to batteries in parallel that I'm adding the voltage?

    Sorry for all the silly questions - I am a newb! ;)

    Series adds Voltage, not parallel:

    (-) Charger 'A' (+)--(-) Charger 'B' (+)

    'A' (-) to (+) = 12 VDC, 'B' (-) to (+) = 12 VDC
    'A' (-) to 'B' (+) = 24 VDC

    BUT (and it's a biggy) the 'A'/'B' connection needs to be attached to the battery bank at the midway, "12 Volt" point.

    This is NOT a recommended procedure because you never really know what's inside the chargers and how well they're made. Three main possibilities; it will work, it will work but heat up the chargers, it will fry the chargers' control circuits.

    And yes I have two cheap 12 V auto chargers with their guts pulled and the transformers feeding 35 Amp bridge rectifiers. It's a back up a back up. It works, but I wouldn't rely on it for very long (low Amperage too, so it doesn't pose too much threat).
  • ChevyNo1ChevyNo1 Solar Expert Posts: 30
    Re: First Time Solar Setup - Need Your Opinions!
    Series adds Voltage, not parallel:

    (-) Charger 'A' (+)--(-) Charger 'B' (+)

    'A' (-) to (+) = 12 VDC, 'B' (-) to (+) = 12 VDC
    'A' (-) to 'B' (+) = 24 VDC

    BUT (and it's a biggy) the 'A'/'B' connection needs to be attached to the battery bank at the midway, "12 Volt" point.

    This is NOT a recommended procedure because you never really know what's inside the chargers and how well they're made. Three main possibilities; it will work, it will work but heat up the chargers, it will fry the chargers' control circuits.

    And yes I have two cheap 12 V auto chargers with their guts pulled and the transformers feeding 35 Amp bridge rectifiers. It's a back up a back up. It works, but I wouldn't rely on it for very long (low Amperage too, so it doesn't pose too much threat).

    OK - now that I understand.

    However - to be safer - I could still break the bank and have each charger on it's own 12V bank correct? I mean I'm only talking a couple of minutes to remove the interconnect right?
  • BB.BB. Super Moderators, Administrators Posts: 29,349 admin
    Re: First Time Solar Setup - Need Your Opinions!

    Not always... Metal tools, battery connections, sparks, hydrogen gas in cells--I would not make disconnecting a battery bank a common process. There is a fair amount that can go wrong when working with batteries---It is similar to working on AC power while still turned on. AC has the higher voltage to watch out for--but storage batteries have a huge amount of short circuit potential (welding wrenches to wedding rings and such) that is usually not an issue with common 120/240 VAC house current..

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ChevyNo1ChevyNo1 Solar Expert Posts: 30
    Re: First Time Solar Setup - Need Your Opinions!
    BB. wrote: »
    Not always... Metal tools, battery connections, sparks, hydrogen gas in cells--I would not make disconnecting a battery bank a common process. There is a fair amount that can go wrong when working with batteries---It is similar to working on AC power while still turned on. AC has the higher voltage to watch out for--but storage batteries have a huge amount of short circuit potential (welding wrenches to wedding rings and such) that is usually not an issue with common 120/240 VAC house current..

    -Bill

    Hmmmmm, good points, food for thought ...

    OK, so going back to what Tony said earlier - if I were to get the Iota 24V charger (25A) - that would work for my intended setup @ 220AH right?

    Also - I assume this would be constantly hooked up to the battery bank, and only would have power when I plug it into the generator - would I have to disconnect anything at all? Or literally fire up the genset, plug the charger in, and leave it until I'm charged? And because it's also a power supply I could still run loads off my inverter, keeping in mind max load of this charger?

    I assume run time and approximate load on the genset would be about the same as my very manual effort ...
  • conntaxmanconntaxman Solar Expert Posts: 125 ✭✭✭✭✭
    Re: First Time Solar Setup - Need Your Opinions!

    To those that think that someone cant build a panel like you buy are just tooo lazy or don't want to do is.Yes you can build just like a small company. Use the same mat. and vac out the air, and seal it.
    come on people ,those that say you CAN'T. sorry you COULD. Hate to rune your day.
  • zeuspaulzeuspaul Solar Expert Posts: 59 ✭✭✭✭
    Re: First Time Solar Setup - Need Your Opinions!
    Also - I assume this would be constantly hooked up to the battery bank, and only would have power when I plug it into the generator - would I have to disconnect anything at all?

    The Iota has a rather large inrush current as it charges up its capacitors. If you plug it into a live outlet you will likely experience some arching at the plug. You may want to plug it into a switched outlet.

    Zeuspaul
  • nielniel Solar Expert Posts: 10,311 ✭✭✭✭
    Re: First Time Solar Setup - Need Your Opinions!
    conntaxman wrote: »
    To those that think that someone cant build a panel like you buy are just tooo lazy or don't want to do is.Yes you can build just like a small company. Use the same mat. and vac out the air, and seal it.
    come on people ,those that say you CAN'T. sorry you COULD. Hate to rune your day.

    can you do this with the same price range or less and guarantee it for 20-25yrs? if so show you can as i'd be for it.
  • ChevyNo1ChevyNo1 Solar Expert Posts: 30
    Re: First Time Solar Setup - Need Your Opinions!
    zeuspaul wrote: »
    The Iota has a rather large inrush current as it charges up its capacitors. If you plug it into a live outlet you will likely experience some arching at the plug. You may want to plug it into a switched outlet.

    Zeuspaul

    Good to know, thx! So - a switched outlet - I assume I would have to build one myself that I could plug into the generator, other end into charger, then just flip the switch?

    So I'd need a surface mount box, wiring (would a hacked extension cord do), an outlet and a switch?
  • icarusicarus Solar Expert Posts: 5,156 ✭✭✭✭
    Re: First Time Solar Setup - Need Your Opinions!
    conntaxman wrote: »
    To those that think that someone cant build a panel like you buy are just tooo lazy or don't want to do is.Yes you can build just like a small company. Use the same mat. and vac out the air, and seal it.
    come on people ,those that say you CAN'T. sorry you COULD. Hate to rune your day.

    Give us a shout in 10-20 years. My original panels have been in the weather for nearly 20 years now.
  • mike95490mike95490 Solar Expert Posts: 8,333 ✭✭✭✭✭
    Re: First Time Solar Setup - Need Your Opinions!
    ChevyNo1 wrote: »
    Good to know, thx! So - a switched outlet - I assume I would have to build one myself that I could plug into the generator, other end into charger, then just flip the switch?

    So I'd need a surface mount box, wiring (would a hacked extension cord do), an outlet and a switch?

    This is EXACTLY what I did, a 12ga ext cord, a 20A duplex outlet, HD light switch and a wall box.

    Start the genset, plug in, enable breaker, and then flip the sacrificial wall switch.

    And when you connect the DC cables, you get a good spark too, off or on, so I just bolted them on permanently, and can charge from any genset with about 2000W capacity.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • ChevyNo1ChevyNo1 Solar Expert Posts: 30
    Re: First Time Solar Setup - Need Your Opinions!

    Cool, thx Mike. I am so new to electrical of any kind that I'm shocked I understood it, ha ha!!
  • ChevyNo1ChevyNo1 Solar Expert Posts: 30
    Re: First Time Solar Setup - Need Your Opinions!

    Can anyone comment as to the ability of the Iota 24V/25A charger being enough for my setup, which is 24V/220AH? I am guessing so, if the same 10% charge rate applies in a 24V setup as it does for 12V ...

    And technically speaking - would it charge up the batteries as quickly as if I went the two 12V charger route? Those chargers being 12V/25A?
  • BB.BB. Super Moderators, Administrators Posts: 29,349 admin
    Re: First Time Solar Setup - Need Your Opinions!

    Why we usually talk about watts and percentages of amps... It scales across different battery bank setups. Watts=I*V...

    Amps and Amp*Hours does not refer to bank voltage, etc...

    However, eventually you need to convert Watts back to voltage / amps / power factor / etc...

    The Iota charger family has a good reputation as something that will do the job reliably. They have a switch--jumper in, charge at ~28.4 volts, jumper out, float at ~27.2 volts (I assume you could remote wire in a manual switch)... So if you are OK with the manual setup--should be fine (you won't be floating with a generator--just AC mains). Is missing Power Factor Correction and Remote Battery Temperature Sensor.

    If you are charging with a "small genset"--Getting something with Power Factor Correction on the AC input would be nice (difference between pulling 0.60 of available power vs pulling 0.95 of available power.

    Xantrex has another line of XC Battery Chargers with all of the neat bells and whistles. I don't know anything about them--but their specifications really look interesting.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ChevyNo1ChevyNo1 Solar Expert Posts: 30
    Re: First Time Solar Setup - Need Your Opinions!

    OK - so regardless of V, you want an average 10% charge rate - since my entire setup will be 220AH - that means 22A charge current right?

    Thanks!
  • mike95490mike95490 Solar Expert Posts: 8,333 ✭✭✭✭✭
    Re: First Time Solar Setup - Need Your Opinions!
    ChevyNo1 wrote: »
    OK - so regardless of V, you want an average 10% charge rate - since my entire setup will be 220AH - that means 22A charge current right?

    Thanks!

    Right, so a 24A charger should be fine in your case.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • ChevyNo1ChevyNo1 Solar Expert Posts: 30
    Re: First Time Solar Setup - Need Your Opinions!
    mike90045 wrote: »
    Right, so a 24A charger should be fine in your case.

    Thanks Mike :)
  • ChevyNo1ChevyNo1 Solar Expert Posts: 30
    Re: First Time Solar Setup - Need Your Opinions!

    I think I am still not clear on one thing - if I were to get the Iota 24V/25A charger/converter - would I have to 'disconnect' anything once the genset is fired up? The converter says it can handle loads - so I'm guessing I could still use the inverter to power loads, while this charger is working off the genset? What about the PV array, does that have to be disconnected when the charger is running?

    And ... would the 40A version be too much charge current?

    Or will either of these actually be a problem with my Yamaha EF3000, which has a rated current of 23.3A? Wondering if that 'high inrush' might be a problem.
  • BB.BB. Super Moderators, Administrators Posts: 29,349 admin
    Re: First Time Solar Setup - Need Your Opinions!

    In general, you can run chargers in parallel (solar panel charge controller, AC charger, DC alternator, etc.). The battery will pretty quickly reach the Absorb voltage (~29 volts) and all of the various charge controller will cut back on current to avoid overshooting the voltage set point.

    The only concern is if you "equalize your battery bank" (flooded cell lead acid batteries)--Then you should disconnect most "24 volt" devices. Equalization voltage can be as high as 30-31 volts--A bit high for standard "24 volt battery systems" (such as those designed for use on a boat or truck). Some AC inverters may shut down when the battery voltage hits 30-31 volts (check the equipment manuals). AGM's are not typically equalized at those elevated charging voltages--so should not be an issue at all.

    I do not believe you need to disconnect the Iota when its AC power has been removed (very low leakage current).

    If you where going to leave the RV parked without sun/charging energy--I would think about disconnecting all loads to prevent any external draining of battery energy. Perhaps either measure the leakage current with a DMM or ask IOTA
    Engineering directly.

    Otherwise, I would leave the AC charger connected to the battery bank.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ChevyNo1ChevyNo1 Solar Expert Posts: 30
    Re: First Time Solar Setup - Need Your Opinions!

    OK, so about the only thing I would want to disconnect in my case then would be the 24V inverter (I assume just using the power-off button would suffice?) - I will have no other loads off the bank other than that.

    Manual does state max input of 30VDC - but nothing about it shutting itself off ...
  • BB.BB. Super Moderators, Administrators Posts: 29,349 admin
    Re: First Time Solar Setup - Need Your Opinions!

    I don't know anything about your inverter--I would not worry about it unless you are specifically equalizing flooded cell batteries >15.0 volts--Should not damage the inverter if it is on or off... If you equalize at 15.5 volts--Being causuous would indicate you should disconnect the inverter (DC Switch/Breaker/Pull Fuse) if you charge > 15.0 volts.

    Problem with electronics--The very small physical sizes of transistors, FETs, create very high electrical fields internal to the silicon devices (and capacitors, etc.). You may not "kill" the electronics with 15.1 volts, but weaken them over time where weeks/months/or even longer--you will have an early life failure for your inverter/electronics.

    Will 15.5 volts "kill"/cause early life failure in your inverter--probably not--but I really don't know. Only the manufacturer has that information.

    We have seen "12 volt car adaptors for computers/etc." fail when operated on a off-grid PV system. Cars usually run around 14.2 volt maximum, and most off-grid systems are ~15.0 volts maximum--And some "12 volt" adapters simply do not survive.

    Is a 40 amp charger too big... What is the exact type of battery you will be charging? AGM or Flooded Cell... At least one brand of AGM's (Concorde) can take C*4 rate of charge (15 minutes to charge)--way higher than you will ever use.

    Otherwise, for flooded cell batteries, C/8 (~13% rate of charge is towards the highest rate * 20 Hour Capacity). A 40 amp AC charger may be a bit large for 220 AH flooded cell.

    The real problem is recharging a heavily discharged flooded cell battery. You can overheat them with too much charging current. Once the battery is >~80% charged, the battery will be at/near the Absorb voltage and the battery charger will be reducing the current anyway.

    Generator wise, assuming 2,800 watt generator, 80% efficient battery charger, 0.6 power factor, and 29 volts charging:
    • 2,800 watts * 0.80 eff * 0.6 PF * 1/29 volts = 46 amps
    So, guessing, for your Yamaha 3000 genset, a "standard" 24 volt battery charger maximum rated output current of ~45 amps would be its limit.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ChevyNo1ChevyNo1 Solar Expert Posts: 30
    Re: First Time Solar Setup - Need Your Opinions!

    My batteries are flooded cell - so I think I will stick with the 25A charger - strongly considering getting the Iota that Tony suggested. Sometimes I just gotta mull these things around in my head a day or two :D
  • ChevyNo1ChevyNo1 Solar Expert Posts: 30
    Re: First Time Solar Setup - Need Your Opinions!

    On to more questions as I think the entire setup through - I am looking at a single cutoff switch, that I would place between the PV array and controller. One like this:

    http://www.amazon.com/Battery-Kill-Safety-Disconnect-Switch/dp/B0017101BE/ref=wl_it_dp_o?ie=UTF8&coliid=I1E15A1FCJN9P6&colid=IZ5O5TNG2Z0O

    This would allow me to disconnect the PV array from everything else. Seeing as I'll have a small array (3 serial panels), I don't think I need a fuse/breaker here.

    I am also looking at the Blue Sea switch (http://www.solar-electric.com/basw1300amp.html), that has 1, 2, 1+2, or off positions. Thinking on '1' I would have the controller. On '2' I would have the Iota charger, and of course the battery bank on common. I suppose most of the time I would just have it in the '1' position, until I ran the Iota off the genset, in which case I'd want '1+2', right? Then if I needed to completely disconnect that side of things from the bank, just switch to off.

    Between the bank and the inverter (which has a power switch) I would just have a fuse, no switch/breaker.

    I assume there also should be a fuse between the controller and the switch? What about between the charger and the switch? And as well between the bank and the switch?

    Or am I doing this all wrong?
  • BB.BB. Super Moderators, Administrators Posts: 29,349 admin
    Re: First Time Solar Setup - Need Your Opinions!
    ChevyNo1 wrote: »
    On to more questions as I think the entire setup through - I am looking at a single cutoff switch, that I would place between the PV array and controller. One like this:
    Looks good.
    This would allow me to disconnect the PV array from everything else. Seeing as I'll have a small array (3 serial panels), I don't think I need a fuse/breaker here.
    You don't need a switch--however, if you wish to turn off the controller for service, reboot it for some reason, etc., then having a switch (instead of waiting for dark/lifting input wiring) makes things nicer

    I tend towards minimal requirements. Doing lots of switches, extra wiring, etc. can get confusing (if significant other needs to "run your system" while you are not there) and more things to go wrong. If you only need to flip the switch once every three years (or throw a tarp on the array)--is an extra switch worth it? No right or wrong answer.
    I am also looking at the Blue Sea switch (http://www.solar-electric.com/basw1300amp.html), that has 1, 2, 1+2, or off positions. Thinking on '1' I would have the controller. On '2' I would have the Iota charger, and of course the battery bank on common. I suppose most of the time I would just have it in the '1' position, until I ran the Iota off the genset, in which case I'd want '1+2', right? Then if I needed to completely disconnect that side of things from the bank, just switch to off.
    Personally, I would put the Iota+Solar one one terminal. And inverter/loads on the other. If the solar panels are charging--the small amount of drain from the Iota is not going to hurt anything.
    Between the bank and the inverter (which has a power switch) I would just have a fuse, no switch/breaker.

    I have lost track of which inverter brand/model you are looking at using...

    Many inverters have no on/off switches (6-30+ watts of "standby" / no load power consumption), some have DC inhibit input (which still uses a 1 watt +/- power even when "inhibited"). And a few inverters actually have a hardwired On/Off switch/breaker.

    For a generic setup--I would wire in a DC / Breaker as an on/off switch for the Inverter circuit.

    You can use one master switch for your entire 24 VDC system--and/or you can use breakers for each major subsystem (AC inverter, DC lighting, DC fan, DC electronics, etc.).
    I assume there also should be a fuse between the controller and the switch? What about between the charger and the switch? And as well between the bank and the switch?
    I am not sure what "controller" you are asking about (solar charge controller, or what)--But, in general, think of the battery as your main source of current. The wiring from the battery to the first breaker/switch should be as short as practical (well supported wiring, tied together, possibly a plastic sleeve, etc.). From the fuse/breaker, then run your switches and wiring to the point of use.

    The Fuse/Breaker is there to protect against any possible fault condition (shorted wiring, switch fails, input electronics failure on inverter, too much loads for too small of copper wire, etc.).

    Things get a little bit more confusing when you have multiple energy sources (house and vehicle battery banks, several battery chargers, vehicle alternator, etc.). But, in general, the batteries are the "unlimited" power sources. Charge controllers, battery chargers, etc. cannot usually output more than their rated current--so you do not have to protect against short circuit current from a 30 amp charge controller (which your wiring can support all day long) when you have 5,000+ amps available from your battery bank (which would smoke your wiring in a handful of seconds).
    Or am I doing this all wrong?

    No... But you may be confusing yourself with a combination of details and choices not yet made.

    Look at your system as "modules". You have the battery bank as the heart of your system--with its buses, breakers, fuses, switches.

    And you have a solar charger module connected to the battery bank.

    And an AC battery charger module connected to the battery bank.

    And an AC inverter module connected to the battery bank, etc.

    For a first level of understanding, there is very little interaction between the PV Charger and the AC inverter. The battery bank "swamps" most of these point to point effects.

    However, this assumes you run a single wire/harness from the inverter to the battery bus. And a second single harness from the solar pv charger to the battery bank.

    If you were, for example, to share one set of wiring from the battery bus to the inverter + solar PV charger--You could have problems. For example, AC inverter have a 120 Hz ripple in their DC input line. This ripple voltage can confuse MPPT Solar Charge controllers if they are all sharing the same wire run from the battery bank.

    Instead, home run the charger and inverter DC wiring (separate cables) back to the battery bank bus points--the battery filters out most of the 120 Hz noise and everything plays well together.

    Once you have a handle on each of the "major modules" for your system and how they work (focused on the battery)--then you are ready to look for other issues as they arise.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ChevyNo1ChevyNo1 Solar Expert Posts: 30
    Re: First Time Solar Setup - Need Your Opinions!
    Personally, I would put the Iota+Solar one one terminal. And inverter/loads on the other. If the solar panels are charging--the small amount of drain from the Iota is not going to hurt anything.

    In this configuration - I am guessing there would be no need/use for the 1+2 switch then ... what are the advantages of this over my initial thought?
    I have lost track of which inverter brand/model you are looking at using...

    Many inverters have no on/off switches (6-30+ watts of "standby" / no load power consumption), some have DC inhibit input (which still uses a 1 watt +/- power even when "inhibited"). And a few inverters actually have a hardwired On/Off switch/breaker.

    For a generic setup--I would wire in a DC / Breaker as an on/off switch for the Inverter circuit.

    This inverter is nothing extraordinary - a PowerBright 1500W 24V inverter ... and it does in fact have a rocker on/off switch. In this case - would I need the breaker?
    You can use one master switch for your entire 24 VDC system--and/or you can use breakers for each major subsystem (AC inverter, DC lighting, DC fan, DC electronics, etc.).

    Since my needs at this point really are minimal ... I am thinking one master switch - right off the battery after the fuse (150A fine??) .. as I mentioned before I do have two powerboxes for relatively small loads that can carry me for a little while ...

    I definitely was going to do different wiring for the charger and the inverter ...
  • BB.BB. Super Moderators, Administrators Posts: 29,349 admin
    Re: First Time Solar Setup - Need Your Opinions!
    ChevyNo1 wrote: »
    In this configuration - I am guessing there would be no need/use for the 1+2 switch then ... what are the advantages of this over my initial thought?
    Your choice... There is no one right choice. The big switch is intended to manage starting current for boat engines... Your system is much smaller and a lighter switch/set of switches would work fine.
    This inverter is nothing extraordinary - a PowerBright 1500W 24V inverter ... and it does in fact have a rocker on/off switch. In this case - would I need the breaker?
    It looks like an "inhibit" switch rather than a large 150 amp switch... Don't know. You can always measure the leakage current with the unit "off" and see if it is an issue for your setup.

    Note that this inverter uses 24 watts with no load--Depending on what your AC loads are and how long you plan to power them (and how much solar power you plan to install to recharge the bank) may affect your final design.

    I suggest estimating your power needs (from loads) and add the 1 amp standby/tare current for the inverter and make sure that your needs match up with the system capability.
    Since my needs at this point really are minimal ... I am thinking one master switch - right off the battery after the fuse (150A fine??) .. as I mentioned before I do have two powerboxes for relatively small loads that can carry me for a little while ...
    Not a problem--It sounds like you are getting a good handle on the entire project.

    I always try to remind people that solar is a game of losses (panels, charge controllers, batteries, inverters, loads) and when you figure everything out--generally there are more loads then there are panels to power them...

    Typically, minimizing your loads as much as possible is almost always better than building a larger PV system. Also, using the smallest inverter that will power your loads is helpful. Sometimes, it is two inverters, one small/efficient/true sine wave for your electronics/battery chargers. And a large/cheap MSW for your power tools.

    For example, Exceltech can have special order true sine wave inverters in the 1-2kW range with 10 watts of idling losses (order the X2 option PDF download). I don't know what the X2 option is or does, or if it will work for you... But this comes at price--probably 5-10x the cost of the MSW inverter you are looking at.
    I definitely was going to do different wiring for the charger and the inverter ...

    Sounds good... Just sharpen your pencil (or run Excel) on your various configuration options and make sure you have enough sun+panels+batteries to do the job you want.

    A good place to start--For AC loads, assume 4 hour of sun per day and ~50% end to end efficiency. For example, 400 watts of solar panels:
    • 400 watts * 4 hours of sun per day * 50% system efficiency = 800 Watt*Hours per day
    A 500 watt load (remember to add in the 24 watt AC inverter to your loads):
    • 800 Watt*Hours per day / 500 watt load = 1.6 hours per day of solar power
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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