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Auto Switch Over To Shore Power

ac DPDT

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#1 PinkFloydBham

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Posted 28 May 2019 - 01:31 PM

Hi, I am new to this forum. I just picked up a 2019 ID and am upgrading the electrical system. I am installing a Tesla 5.3 Kw battery supplied by 4, 160 watt panels. I am making up cables to connect the components as I speak. I am relatively new to this and have a question to anybody who has gotten involved in alternate power supplies for these little domiciles. I intend to be capable of running off grid for  more remote adventures but I want to be able to take of advantage of shore power when available to run the ac during hot weather (sans generator). 

I want to have my electrical system automatically switch from the self powered solar system to shore power when I plug into a public 30 amp source like a camp ground or my house. It was suggested that I use an AC DPDT electromagnetic relay. It switches magnetically from the solar to shore power when ever the circuit is energized by plugging in to the grid.

Does anybody out there have any experience with these relays? any comments as to feasibility would be appreciated.

 

I thought the use of an automatic transfer switch was going to be helpful but it is not action I need since it senses the state of charge and switches over to public power when the solar is low. I attached a screen shot of a dpdt relay but I need 120 volt rather that the 12v dc shown.

Thanks,

Pink Floyd

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#2 PinkFloydBham

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Posted 06 June 2019 - 04:11 PM

Problem solved.    -------   FYI.

I bought this relay for $20 + shipping and tax, about $32 total. It has a normally closed set of contacts which I wired my solar/batt circuit to. With a hot wire on one pole and neutral on the other pole the current passes from the inverter through the relay and into the existing panel which has a 120v side, a 12v dc side and a built in charger for an on board 12v FLA. 

I wired the normally open contacts with the 30 amp cord to the shore power and a short pig tail plug for a generator to plug into. When the NO circuit is energized the relay switches the entire circuit (both hot and neutral) so any power surges are not shared with the dormant circuit. No room for human error and the wife and grandkids do not have to remember to turn the knob(s).

I also added a 24v dc to 13.8v dc converter off the battery to run additional exterior lights. I got some exhaust pipe scraps from a muffler shop and split them and opened them out flat like strips and painted them white. Right now they are mounted on the rear glass of the tow vehicle (98 GMC) with 3M VHB.

Two 54 watt LED flood/spots (about $11 each) with a 2$ waterproof push button switch on Amazon. It is like lighting up a landing strip and uses minimal power.



#3 PinkFloydBham

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Posted 11 June 2019 - 04:30 PM

Well, I bored a hole in the floor today. Used a 1.5 inch paddle bit about 3" inboard of the batt box. in the rear cargo hold at about the edge of the back window on the driver (port) side. I had to make sure i missed the frame spars. I ran a 10 awg, solar extension cable with 2, MC4 connectors through it and will drop a 4 awg ground to the frame on one to the chassis attachment bolts to make sure I have enough "earth".

This whole project started because I wanted an alternative energy source and it was over $1K from the factory for a "pee wee" system from the factory. Not mocking' em, it is just a new technology.

I have my son visiting right now and he can help me get up on the roof to put the collectors down. I am putting a 4" pvc pipe in the ravine along the Mohawk and securing it with full length strips of velcro. I am putting 2 160 watt pajels on each side with the junction boxes facing each other in the center and each side is wired in serial for 36 volts then paralleled with the opposite side via mc4 splitters. Then they pass down the inside of the pvc pipe and drop down at the back near the license plate and run into the frame then into the coach via the brand new hole in the cargo hold. 

I have all my electronics programmed and connected to the to the managers and monitors, but right now, I have to go cook for the grand-kids.

I'll post later.

Pink



#4 PinkFloydBham

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Posted 16 June 2019 - 06:41 PM

Got it! I put the relay in a 6x6x 4" tall box, with a lid. I ended up having to cut the shore line cable and installing the relay between the panel and the factory cable. I left about an 18" pig tail out of the back of the panel. I tried to use a 3 conductor, 10G leftover cable with a rubberized cover from making up the patch cord from the relay to the inverter, but it just wasn't long enough, and I was going to have to pull out the distribution panel and disconnect all the immobilization clips, ground connections and the wiring harness in order to get the panel uninstalled to get to the 30 amp shore power supply connection.

This was a major PIA for me since I am a rank "armature"  in all things 'lectric. Boy, making up connections and wiring crimp connections inside of a metal box, inside of a fiberglass cabinet, down around your feet with no decent light is a "task" for a fat, old man. Plus, it was 90 degrees in there, even with an imported fan.  --- that is over now.------     When I plug in the shore power cord, I hear this click, and all the power switches over, -- no sparking or buzzing.



#5 clover

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Posted 17 June 2019 - 01:48 PM

here is a video on installing a Tesla battery install in an RV

 

https://www.youtube....CDY&app=desktop


Happy Trails!
Clover
2003 17' SD
2002 F350 Diesel Crew Cab
(I know it is overkill but we live on a real ranch it takes a vacation with the Casita)