DC and AC questions...

[leo3000]

might have allready been asked, but I have a couple quick questions

DC:
I am planning on wiring a 12v deep cycle battery such that it is connected in parrallell with the main bus batteries a few seconds after turning the bus on (and disconected when bus is off). I want to do this with a solenoid and delay timer as shown in the diagram, do yall see any issues with directly connecting the batteries like this?



AC:
I have done some funky stuff in an attempt to be able to switch from the inverter as a power source to shore power as a power source. I am really trying to keep things cheap as im sure yall can tell.. I know it looks dumb having an invertor connected to a converter, but if i can keep the converter from actually converting when the inverter is the source, I think its the simplest option.. Im wondering, if I were to break that circuit of the 12v's going to battery, would there still be a draw from the converter? I feel like there would not be but maybe there are some sort of losses in the transformer or something like that. maybe I could figure out a way to switch it off before it goes to the transformer..?

thanks
Leo

[roach711]

Picture isn't displaying for me.

Why the delay circuit? The relay-type battery isolators I've seen don't use them.

Here's a good thread on wiring:

http://www.skoolie.net/forums/f13/el...ing-13059.html

[leo3000]

the picture shows for me but maybe this link will work for you

https://drive.google.com/open?id=1yu...5-TUccpmH40NJg

[Tango]

Me either...don't see anything.

[leo3000]

ok.. attempt # 6, typed up in a word document first lol

so the converter has a 30a plug as the input and 4 fused 120vac circuits and 1 12vdc circuit as the output.

I don’t want to be able to switch between inverter and shore power at the source of the 120vac, that way I can easily switch between shore power and battery power while using all the same outlets, etc.

I want to see if I could wire the inverter to the converter in order to use the 4 120vac fused circuits for all my ac power needs… hopefully bypassing the actual converter someway or the other

Sorry the pic wont work.. maybe because I am a new user… here is a link that will hopefully work:

https://drive.google.com/open?id=1yu...5-TUccpmH40NJg

[roach711]

A CONverter converts 120v AC from shore power into 12v DC and often incorporates a battery charger. Your shore power/generator supply circuit attaches to the converter input (usually through the breaker box). The converter outputs go to your battery or DC circuits and the charger outputs go to the battery bank.

An INverter converts 12v DC from the batteries into 120v AC. The inverter input attaches to the battery bank with a fat wire (basically a battery cable) and should be installed very close to the batteries to keep voltage drop to a minimum. The Inverter outputs typically go to a few isolated AC outlets while the remainder of the AC circuits are powered from shore power through the breaker panel. Unless you have some way to switch your breaker box AC input between shore power and inverter power, keep your inverter and shore power circuits separate.

One easy (but not cheap) way to simplify this mess is to use a standby inverter which attaches to both the battery bank and shore power and automatically switches your AC circuits between the two. No need to have separate AC circuits. The standbys typically include a converter/charger too.

In your schematic, the converter (when attached to the inverter) is charging the batteries while the inverter drains the batteries to power the converter.

[leo3000]

right, I think your not quite getting my question but I really appreciate the response.

Im going to check out the details of how my power converter is wired when I get home tonight and see if its possible to switch the converter off while still utilizing the bank of 120v circuits on the power inverter!

(also, I have quite an old converter, not 100% sure how it works or how it compares to the standard.. there is only one positve dc wire and one negative dc wire coming out.. i need to check the voltage across them)

[CaptSquid]

If I read your post correctly, what you're proposing is a perpetual motion machine. The Inverter takes 12VDC and turns it, hopefully, into 120VAC. Then, you want the converter to charge the batteries with the big motor.

Won't work unless you actually get out and switch them over.

[leo3000]

No no no... thats not what im saying but i def see how yall are thinking this..

i am trying to switch between shore power and the inverter AT THE SOURCE (so all outlets can be powered by either) - this is the MAIN goal (and i wana achieve it without spending $$ cus i dont have $$)

the problem is the only way I have to switch the circuits at the source, which means it has to go through the converter just about no matter what, obviously i dont want to invert DC from the battery to AC in the convert it back to DC. what I do want to do is invert DC to AC then bypass the converter to the same 120vac circuits that the converter has running out of it when it is plugged into the shore. ie NOT convert to DC again.. just bypass converter to its AC circuits - this is the part I dont know how to do.

if I cant figure out a way to do this i will likely opt to having seperate circuits for shore and inverter like roach said .. i just want to avoid that if its possible!

[CaptSquid]

It can be done, but it's called a cross-over circuit breaker. For example, you have solar panels that bring in DC to a battery bank at your house. But, you're not using the battery bank while the local utility company supplies the AC you desperately need in the house. But when the utility company fails to perform as advertised, you want DC to turn into AC with very little intervention on your part. Correct?

[roach711]

The converter works off shore power and makes DC. You use the converter only when shore power is available.

The inverter works off the battery bank and makes AC power. You use the inverter only when there is no shore power available.

The inverter never powers the converter so there is no reason to connect them.

[jazty]

The cheapest way to do this is with a basic outlet and plug.

Make all of your in-bus wiring come to a single 120vac plug that hangs near the inverter.

Your inverter already has a 120vac outlet. When you want to run off of the batteries connect your plug to the inverter and turn it on.

Make the shore power come inside the bus to an outlet near the inverter. When you want shore power you can connect your interior circuit there. Your 12v converter can also have a plug and connect to that same outlet.

Cheap. Simple.

Otherwise look into transfer switches.

[leo3000]

CaptSquid and jatzy, you understand what i am trying to do

jatzy I like that idea. i need to try to get my mind away from sticking with excactly the way my converter is meant to be set up.. its got 4 120 circuits coming off of it, but if I had just one that split to 4 later it would pretty much solve all these problems i've been talking about..

everyone else, im sorry for not clearly explaining myself..

im gunna look into the cross-over circuit breaker

[roach711]

Your plug idea is foolproof in the bargain.

I'd also want a breaker box in the plan. Assuming a 30 amp service the shore power panel breaker wouldn't protect your 15 amp wiring. The breaker box also gives you an easy way to shut off the converter.

[leo3000]

thanks guys, i drew up what i may do.. (not shown but i will have everything protected with CB)

here i put a switch on it instead of having to swap plugs.. only problem is if im not paying attn. i could forget to switch the inverter off and plug into shore power.... i could fix the problem with a DPDT switch instead but they cost 85 $ and my budget doesnt afford it unfortunatly, i know that sounds pathetic its just kina the way it is

[jazty]

Originally Posted by roach711

Your plug idea is foolproof in the bargain.

I'd also want a breaker box in the plan. Assuming a 30 amp service the shore power panel breaker wouldn't protect your 15 amp wiring. The breaker box also gives you an easy way to shut off the converter.

Yes, of course. I fully agree. I wasn't drawing out the whole picture and probably should have.

Bus outlets   \ 
              |-> breaker -> plug
12v converter / 

Inverter -> batteries

Shore power outlet -> shore power plug

That's a better set up.

[roach711]

I may be reading the new drawing wrong, but it looks like you're trying to power the same receptacles with both the inverter and the converter. Is that right?

[roach711]

Originally Posted by leo3000

so the converter has a 30a plug as the input and 4 fused 120vac circuits and 1 12vdc circuit as the output.

My bad, I missed this part so what you're trying to do makes sense. I'd never seen a converter that also had AC plugs.

[leo3000]

yes you are tracking with me now roach, I was hoping to bypass the converter part and jump straight to that.. sorry for the lack of clarity with my explainations, I need to do a better job proofreading!

[leo3000]

just looked at everything ......

it's a normal converter

sorry, my grandfather said it was 120 and the wires were like 120 colors......