AC/DC...I'm on the Highway to hell.....

Shorty Wandermeyer · 02-11-2021, 03:05 PM

Hello fellow Skoolies. I am seeking the wisdom and experience of the community! I thought I had a grip on my electrical set up and then I watched one too many videos. Now I find myself confused and not so confident. Is there any way that someone would be willing to help me sort this out? I'll list what I've got...what I can't figure out is how it all goes together and what I really need vs what I could have if I was sitting on a mountain of cash.

Here is what I have:
Renogy 200W solar with Adventurer 30 amp Charge controller
2 X 100 ah Renogy batteries
3000 watt pure sine power inverter
Arterra WF-8930 30amp AC/DC distribution box

On AC/Shore power I'll be running:
Air cond.
cook-top
tankless water heater
standard outlets X 4

On 12V I'll be running:
LED lights
water pump
vent fans
3 x charging outlets

I think I need a converter in the mix somewhere...otherwise how do I run 12v items when on shore power? If I'm on shore power do I disconnect the solar from the system? My head is spinning from too many youtube videos and too many experts!

Ronnie · 02-11-2021, 06:22 PM

All my 12 volt and the fridge run off the batteries and solar all the time even if plugged into shore power. Shore power is just for a/c or to run power tools. Same with the genny. I am not by any means saying this is the right way but just how I do it, and it has worked out well for me for over two years, other then one time. I will must likely add a battery charger that can be used off shore power/genny for when there are too many days without sun. That happened to me a few months ago. Now I was trying to charge some boat batteries as well for an electric boat. So really pushing the limit of my system.

200 watts of solar should do what you want. I have 400 but am also running the fridge from solar. I am using the MPPT controller from Renogy. Really happy with it. A noticeable improvement over their non mppt controller.

Danjo · 02-11-2021, 06:48 PM

A couple ways you could go would be to put your batteries on an appropriate charger.

You could also install a converter and a switch that switches your fuse panel between the converter and battery bank

rossvtaylor · 02-11-2021, 08:53 PM

Yes, like Ronnie and Danjo said. People tend to really overcomplicate this. When you're on shore power, you still have your 12V system and batteries. All you need then is some way to charge the batteries. A simple battery charger will work for that. Think of your batteries as your power source, then work back towards methods of charging those batteries...solar, vehicle alternator when driving, charger when plugged in. As you said...if you had a boatload of money you could get as complicated as you want...but you can keep it really simple and be just fine.

Shorty Wandermeyer · 02-12-2021, 10:04 AM

Thanks for the input folks. I find myself wishing I would have purchased the distro panel that had the converter/charger built in...I think that and a cut-off/isolator switch would have it licked.

s2mikon · 02-12-2021, 10:14 AM

Think of simplicity, redundancy and modular stand alone components. This will make it more robust and easier to trouble shoot and repair, not if, but when it fails.

Danjo · 02-12-2021, 10:34 AM

I have an inverter/charger that can connect to shore power to charge the batteries. I haven’t had the chance to hook it up and haven’t had the need.

DeMac · 02-12-2021, 11:02 AM

(Quote)
30 amp Charge controller
2 X 100 ah Renogy batteries
3000 watt pure sine power inverter
Arterra WF-8930 30amp AC/DC distribution box

On AC/Shore power I'll be running:
Air cond.
cook-top
tankless water heater
standard outlets X 4

‐--------‐------

Yes, focus on one system, one circuit. One step at a time. First step.: Add up the total load requirement. First.

What is the nameplate rating of each of these items? Amp/Volt

example:
3kw inverter = 25a/120v
AC (w/o heat?)= 20a/120v
Range = 30a/240v
W/H = 30a/240v
4 recept = 20a/120v

*For the recepts, use the amps of largest item you will ever plug in.

Will you use small appliances on any of the 4 recepticals? Ex: Micro, Toaster, Crockpot, Hairdryer, Heater, Vacuume, Power Tool?

Didn't see refrigeration listed?No fridge or 120v or 12v?

From here we can size the breakers, entrance wire, number of circuits, panel.

(Note: 30a main panel and 30a wire WILL be overloaded with listed load)

rffffffff · 02-12-2021, 11:28 AM

You need a charger to charge 12v when on shore power or in emergency, and a switch to isolate the inverter ac from the shore ac. I like my iota brand charger but others have different favorites.

Not sure what your distribution panel really is but it could contain the isolation function? If not I ordered a three phase 63a switch from Amazon that works fine.

Here’s my diagram that I drew for someone else, hopefully it helps.

https://imgur.com/a/ATkTUFK

Shorty Wandermeyer · 02-14-2021, 10:41 AM

So here's the ratings for the appliances/lights etc.

A/C
Fridge-? 120v but all I can find is that it has a yearly usage of 358kwh (outlet)
AC/Heater-120v 1350w/11.25amp (outlet)
Tankless water heater-120v 1440w/12amp (outlet
Microwave-1000w 120v/9amp (outlet)
outlets- additional at 10amp ea.

DC side:
Water pump- 12v 8amp max
LED lights- 10X 5watt
outlets-2 w/built in USB charging

I'm probably missing something. I think I'm going to change out my distro box for one that includes a converter charger such as the WFCO WF8955PECB 55 Amps Power Center Converter Charger https://www.amazon.com/dp/B004BC59S6...v_ov_lig_dp_it

DeMac · 02-14-2021, 12:17 PM

So here's the ratings for the appliances/lights etc

Ok. That's it.
One system at a time, just a/c load calc. to safely size line (supply) material requirement.

This sounds like a standard five circuit home kitchen with w/h & a/c. Orig Post included a 120v cooktop, do you have that rating? Or just describe it to me. Also, the plug in inverter 3kw inverter load requirement?

You'll need 8-10 spaces or larger. Panel rated at least 50a. Larger really with the cooktop, instant w/h.
6/12 space Square D or
Seimens 8/16 (better)
Only $35-$50.

Circuit breakers:
15a fridge
15a micro
15a wtr heater
15a a/c (*no heat)
20a cooktop (1 or 2 burner)
20a inverter (check amp)
Plus (4?) more brkrs @
15a ea

1440 = (12a×120v) is a magic number to a 15a brkr, beyond that, they trip. All brkrs ought break the circuit beyond 80% that's why microwaves & hair dryers are 1440, yet commercial use = 1600 (20a)

Your 50a main will trip at 40.0001 amp.
Pick 3-4 items to at a time, no problem.
Fridge, cooktop, micro. Or
a/c, inverter, hot wtr, fridge.

Most choose to use propane and or diesel on any heating appliances, water, cooktop, furnace.

* electric heat usually has a higher draw than the a/c with which it's paired. Just dbl check.

Shorty Wandermeyer · 02-14-2021, 01:43 PM

Thanks DeMac.

Inverter is 3000W/25amp pure sine. Sounds like I need a bigger distro panel and a converter/charger...and of course more fuses.

Thanks for breaking it down.

rffffffff · 02-14-2021, 02:10 PM

I would look hard at the water heater. I’m not sure what you’re looking at but if it’s electric hot water and you’re ever going to be off grid you should look at something that consumes less power, propane based most likely.

Your overall consumption will be really high compared to a typical bus but if you’re gonna be plugged in a lot it’s not that big of a deal. Otherwise the battery bank is going to have to be ludicrous.

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