Upgrading hunting cabin

SolMan
SolMan Registered Users Posts: 15 ✭
in PV Installers Forum - NEC, Wiring, Installation #1
Hi there.
I've run across a situation where a client has a cabin wired with 12V lights in several rooms. There are also 120V outlets that run off a generator-fed panel, but all the lighting is 12V.

They want to add a solar system to run 120V appliances including TV, microwave, DVD, satellite, phone chargers, etc.

Are we better off to convert all lighting fixtures to AC and run everything off the inverter, or is there any sense in keeping a separate 12V system?
If we ran a 48V battery bank, is there a reasonably priced DC-DC converter to run a dozen 12V lights?

Thanks for any advice!
:D
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Comments

  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #2
    Re: Upgrading hunting cabin

    Are the lights wired with NMD14 wire? What are the periods of use of the 120 and 12 v systems?
    Assumed: the light are powered by a battery. What is charging the battery now? Are the lights LED or CFL? what is the amphr usage & load of the lights?
    Is P&Q a valued issue? (peace and quiet).

    To me it may be simplest to stay with a low load lightning system and power the 12v with a 24 or 48V system. the 12 v could be supplied by 1 120w+- panel if not too large and a PWM CC.
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
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  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    #3
    Re: Upgrading hunting cabin

    Is the inverter "always on" anyway? If so, I would go with everything running off the inverter. If not, then at least some of them should be DC. My opinion anyway. I did have a split system, but over time moved everything to AC as battery voltage changes were affecting light output too much with the DC lights.
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #4
    Re: Upgrading hunting cabin
    waynefromnscanada wrote: »
    Is the inverter "always on" anyway? If so, I would go with everything running off the inverter. If not, then at least some of them should be DC. My opinion anyway. I did have a split system, but over time moved everything to AC as battery voltage changes were affecting light output too much with the DC lights.

    I too had. Slit sytem, but nearly evrything except the radio and th fridge light has gone 120 vac.

    Tony
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  • SCharles
    SCharles Solar Expert Posts: 123 ✭✭
    #5
    Re: Upgrading hunting cabin

    For a part-time place, the easiest, simplest thing to do is switch the lighting and go all AC. What runs the lights now? Generator, small PV? I am not clear from your post.

    My house is split. All lighting, refrigeration, fans are DC. Everything else is AC. But I built this place back in the mid 80s and things have progressed, technologically, in the PV area since then. If I were doing it now, I would very likely just go with a straight AC set-up. Also, "back then," the cost of pv panels was quite limiting to many of us, and any little thing one could do to keep the needed array size down was worth it. Now, not so much, to my way of thinking.

    However, my system is zero trouble. I have completely separate circuitry for DC and AC, of course, and it is no problem or hassle. But the absolute simplest system would be dedicated to one or the other. With all AC, no additional conversion and everything can be controlled from one breaker panel and all outlets and lines in the cabin will be the same.

    Twenty-plus years ago, inverters were less efficient, most of them, and people strove to save every amp-hr possible by using as many DC appliances as they could. To avoid inversion loss. One can still avoid loss with modern equipment, running some things DC. However, and especially for a part-time gig, those losses are minimal and simplicity causes almost everyone I know to go with straight AC systems.
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  • SolMan
    SolMan Registered Users Posts: 15 ✭
    #6
    Re: Upgrading hunting cabin

    The system currently consists of (4) 6V golf cart batteries and a small solar panel (maybe 75-85 watt, it's high up on the roof and I haven't looked at it closely) charging them.
    I believe the house wiring is #12 ROMEX. The 12V indoor lighting is a mix of incandescent and CFL. There are 8 fixtures inside and 2 outside, daily usage could be 1,000-1,500 watt hours. A couple of the fixtures are probably 60'+ from the batteries.
    Currently the 120V system is powered by a Honda 6500 watt gen manually started by a switch inside the cabin. Limiting generator usage would be ideal, but not totally necessary since the AC appliances are mainly only used during hunting season, so having a PV system large enough to power everything constantly for 2 months/year doesn't make sense financially.

    Peace & quiet will be necessary for a few hours/night when watching TV/movies (gen can be heard inside the cabin). There will be a ~200 watt TV, DVD, Satellite receiver, microwave...but probably no curling irons ;)
    Daily AC watt hours could be 2,500-3,000. This may expand in the future.
    The inverter will be always on during these times.

    Also, the fridge is 12V/Propane and will remain so if it makes sense to keep it.

    Maybe a 48V bank (expandable) for the inverter and then running the 12V system off a totally separate battery would make sense?
    Thanks for all the input.
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  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #7
    Re: Upgrading hunting cabin

    without the benefit of exact numbers from the panel and batteries, IMO you are under paneled ( & deficit charging) wrt to keeping that large bank happy during the period you are not there. you need more amps to keep the batteries from deteriorating over the winter. If you supply the specs of your equipment they can be evaluated.
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
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  • SolMan
    SolMan Registered Users Posts: 15 ✭
    #8
    Re: Upgrading hunting cabin

    Sorry westbranch...I meant to say the current batteries and panel would be removed.
    I'm just wondering whether to remove the DC lights also and run everything off AC. According to SCharles it sounds like that may be the simplest way to go.

    Thanks!
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  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #9
    Re: Upgrading hunting cabin

    OK, no problem... so if the owner is not familiar with PV (using it to totally power the cabin) I would suggest that you use the existing batteries as a 'learning set' and when they die form old age, heavy use or abuse, they can be upgraded to a new set. Lots to learn from that set.
    ps I think 24 V would be ample for a seasonal use place... assume mid size GCB with 250Ahr @ 20 hr rate would give 3,000W (50%)max usable.
    pps don't forget to include a battery monitor in the new system.

    hth
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
    · Share on Twitter

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