Our off-grid cabin is nearly enclosed so it’s time for electrical. I’m in New York State and my county requires a county-licensed electrician. I found a well-recommended gentleman, but his requirement is to start from the the outputs of the inverter (he doesn’t want to handle the solar equipment, just the 120/240 v AC stuff). So I need to install the solar equipment myself.
What I want to know is if it is OK to place a Victron solar charge controller, a Victron dc-dc step-down transformer, and a Victron Autotransformer in the same enclosure (assuming it’s well vented).
Would appreciate any sage or scientific or manufacturer advice.
THANKS,
Kevin
an “encösure” could be anything from a small box to a large hall
OGPS
(Ed @ Off-Grid Power Systems - offgridps.com)
3
Yes, that’s allowed if well ventilated as you suggest. It’s not required to do so, however, especially if your cabling is protected by conduit or otherwise uses wire and cable listed for the purpose.
Does your AHJ (authority having jurisdiction) require permitting and inspections for off-grid installations in a cabin? I don’t know your area so I’m just asking the question. We’ve done off-grid cabin designs for customers in NY and New England states that didn’t require permitting for the power source. They mostly cared about the electrical distribution in the home, which is what your electrician is talking about.
Anyway, sorry to be pedantic. We usually ask the cabin builder or owner to set aside a little space for an “electrical closet” where batteries, inverters, MPPTs, etc are installed with a lockable door. Better yet, install batteries and equipment in a small outside shed and simply feed it inside to the main electrical panel like you would a generator. Quality, commercial, listed batteries are safe for use indoors, but I’d still prefer them outside. They may not burn and catch fire, but a venting cell puts out a LOT of hydrogen gas that can explode if contained and near a source of ignition. If you put them outside or in a separate building (even a very small shed), then you don’t have to worry about a cell venting inside your home.
Thanks for your thoughtful answer (and career comments!) I was mainly concerned about electrical shock and containment in the event of a failure of the MPPT, the DC-DC charger, and Autotransformer (and I like it tidy!) Our inspector in the Catskills told me if the solar array is on the ground, it doesn’t need inspecting (we have always had it on the ground due to fire concerns.) Once the solar cable comes in the cabin it must be handled by electricians licensed by the county.
Regarding the potential venting of gases, I have considered putting everything in a well-built 8’ x 8’ shed we bought, but I was worried about the temperature in the winters. Instead I was planning to put the batteries in the insulated basement below the heated space and install an exhaust fan to remove any gases from the battery area.
Heat, fire, explosion, loss of life, loss of property…
OGPS
(Ed @ Off-Grid Power Systems - offgridps.com)
6
In an off-grid situation in UPNY, it would be crazy to put solar panels anywhere other than the ground. You don’t want to be clearing snow off panels on the roof.
Insulate the shed, including the floor, walls, doors, and ceiling and use internally heated batteries and you won’t have issues. Even with an insulated floor, don’t put the batteries directly on the floor so the heat doesn’t flow from the batteries into the floor. Use a bit larger shed and you can also use it for storage or put your well water pressure tank in there, too. Consider installing a mini-split heat pump of suitable size. Set it to 50°F in the winter and 80°F in the summer and the equipment will be happy.
Give us a call if you want some design help for this. We have quite a few customers in NY.
which heat? my batteries, i see with a IR Camera they get a little bit warmer, but i don´t even feel it with my hands
OGPS
(Ed @ Off-Grid Power Systems - offgridps.com)
8
In cold climates and outdoor shed, the batteries will need internal heaters. And if the batteries are in direct contact with the floor the lowest cells can fall below 5°C
