Shore Power Question

[RogerD]

What is the proper way to set up a shore power plug to charge batteries and run AC appliances?

I was looking at some AIMs inverters that are also chargers.

I also have heard people talk about an automatic transfer switch, but not sure about this?

When you choose a plug, does it matter if it is 15, 30 or 50 amp? I see stepdown adapters are available, so should you just use a 50?

Is there a way to by-pass the inverter?

 

[Weight]

How much power do you need? What 120V appliances? You need a transfer switch if you have two 120V supplies, such as shore line and generator, or even inverter, if you have any part of the 120V circuits from both supplies. I know; Not at the same time, that is the idea. Any campground with 50 amp service will have separate outlets for 30 amp and 15/20 amp. But some will not have 50 amp outlets. If you don't need that much power, two 120V 50 amp circuits, just have a 30 amp plug with a 20 amp adapter.

 

[tx2sturgis]

There are different answers depending on what you are trying to do.

Is this a retrofit of an old motorhome?

Or are you starting from scratch on a cargo van or cargo trailer?

Will you need to run a few small appliances, or multiple A/C units, a toaster oven, microwave oven, and large power tools all while charging 4 large coach batteries?

There is no single, simple answer, unless we know what the end result should be. 

Generally speaking, a van or small cargo trailer can get by with 15 amp service.

A mid-sized travel trailer or mid-size van/bus/boxtruck conversion might need 30 amp service.

A larger trailer, bus conversion, or motorhome with multiple A/C units and lots of electric cooking appliances will need 50 amp service.

 

[RogerD]

I have a chevy express extended cargo van.

My plan is...

Six 200w solar panels
Eight 235ah 6v golf cart batteries.

Do not know which charge controller or inverter I will go with.

I also plan to get a portable 2000w generator.

I will be running...

5000 BTU AC. Which I expect to pull about 35 amps or so.

12v 50q refrigerator
12v TV (optional)
12v lights
12v Fans
Laptop, hotspot, cell booster, etc...
Undecided on what to do for a stove. Propane or electric.

I'm in FL and not too far off till the AC won't be needed and since I'm just staring this. I can probably just do a portion of the solar to start and add the other part before it starts getting hot.

My main goal is to be able to run the AC as much as possible.

 

[John61CT]

If you go big AC like that, check out Victron combi units with PowerAssist.

All the transfer stuff automated, can combine shore and bank + inverter power as needed when the shore power is sub par.

Not cheap of course, but can last decades.

 

[tx2sturgis]

Six 200w solar panels
Eight 235ah 6v golf cart batteries.

Thats a large, and very heavy system. Make sure of your total weight capacity before you put in 500-700 pounds of batteries and panels, plus all the other items, cabinets, water, food, A/C unit, generator, gas cans, supplies, appliances, etc. If this is a 1500 series, you might need to pay close attention to the weight of all the pieces you will be adding.

I will be running...

5000 BTU AC. Which I expect to pull about 35 amps or so.

A 5000 BTU A/C window unit should never pull 35 amps on AC power even when starting. There will be a LRA rating, maybe 15-20 amps or so, but it is designed to run on a wall outlet which typically has a 15 amp rating. 

Running amps on 120v AC will be about 5 amps, give or take an amp or two.

Your DC amps pulled thru an inverter to run this A/C could be as high as 60 amps or more, but this amount of current will not be flowing thru your shore power system.

 

[RogerD]

I was looking at this AIMs unit since the transfer switch / charger is built in.

However, I don't know if something like that is the way to go or do it another way.

https://theinverterstore.com/product/2000-watt-pure-sine-inverter-charger-2/

 

[John61CT]

Reco inverters: Xantrex is good but terrible CS attitude. Magnum is the best,

Vanner, Victron, MasterVolt, Sterling, Outback, ProMariner but pricey.

Samlex and Tripplite solid middle ground. I've heard Morningstar is good.

 

[Trebor English]

I'm in FL and not too far off till the AC won't be needed and since I'm just staring this. I can probably just do a portion of the solar to start and add the other part before it starts getting hot.

It is not optimum to mix new and old batteries.  If you buy some now and some next spring you will have a mix.  It might save you some grief to go in with a plan.  The plan could be to ignore the small age difference.

 

[Weight]

Rethink your air conditioner. Maybe get a Kill-o-watt meter and check. The startup surge could be large and not show on any meter. If you measure 10 amps on the 120v side the inverter will pull 10 times that. My microwave runs just fine on a 15 amp 120 volt outlet. It pulls steady 150 amps (measured on meter) from the battery bank using the inverter.
That is 600 pounds of just batteries.

 

[John61CT]

Aircon off batteries, when feasible at all, is **very** expensive and even then just a small part of the day.

In effect just time-shifting ICE generation a bit

 

[picopat]

Hi RogerD

On the air conditioner power usage I assume you're talking about 35A DC current into the inverter to run it (35A*12V = 420W) which is in the right neighborhood for a 5000 BTU air conditioner.

I have the 1000W version of the AIMS inverter/charger but mine came from Renogy. It looks like AIMS power OEMs these to Renogy and other resellers - they just change the paint color and a few labels.

I am very happy with the inverter/charger. I've tested some hefty loads near it's surge rating and it works as expected. I would expect even my 1000W inverter to tolerate a 5000BTU air conditioner, even considering start up surge current. Should be no problem for the 2000W unit.

The built in charger and load transfer make the install nice and clean. You just wire shore power to the input and all your AC loads to the output. When you have shore power it switches to use that automatically (but I think you have to set a few dip switches to configure it that way). The unit has it's own breakers on input and output but I added my own anyway.

I'm wondering where you're going to put six 200W panels on the van? I have two 60-cell 200W panels plus a MaxxAir fan on my Ford Transit 250 and I'm out of real estate.

 

[RogerD]

Yes, 35a @ 12v.

The AC has a soft start and eco mode. During cycling, it doesn't run the fan.

I have an extended chevy express.

The panels are like 58.7 X 26.6. I should just barely be able to get 6 panels on the roof.

I may just go with a 1000w inverter. I read you should go with the smallest size that you will need. So, 2000w is probably far more than I would really need. Not sure what to do. This is all fairly new to me.

 

[LoupGarou]

On my truck camper I use a 30amp SmartPlug and SmartPlug’s cord set with factory terminated ends for my shore power connection. Most of the time I’m plugged into a 20amp outlet on the outside of a house using an adapter.

I’ve been running the rooftop A/C, a Dometic chest cooler, led lighting, tv and recharging things as I need too.

 

[Weight]

If you plan on just one item on the inverter you can size the inverter to the smallest you may guess you need. You might get it right. I would recommend you buy a quality inverter rather than multi labeled china dolls. Samlex, made in Taiwan, is a quality device at a reasonable price point. There are others, but I'm experienced with a 2000W samlex, and it doesn't shut down on the higher voltages from the solar. Don't depend on a 1000W. Get at least 2000W for any 120V household appliances.

 

[picopat]

I may just go with a 1000w inverter. I read you should go with the smallest size that you will need. So, 2000w is probably far more than I would really need. Not sure what to do. This is all fairly new to me.

Cost is the only reason to go small as possible. It won't hurt anything to go with a bigger inverter. Besides, with the big battery bank you're going to use you may decide it's worth having 70A of charge current instead of the 35A you'll get from the 1000W model.

Sent from my Nexus 6P using Tapatalk

 

[Jack]

My main goal is to be able to run the AC as much as possible.

I found THIS VIDEO helpful and encouraging since a lot of AC is important to me, too.

 

[RogerD]

Thanks, will stick with getting a 2000w inverter.

I was looking at an AIMs unit, but I just read a post from someone that has the same one and it uses like 5 amps just to run / no load. That's not cool.

So is the best way to add shore power to just get an inverter that has a transfer switch / charger built in?

 

[Weight]

Get a separate battery charger, hopefully one like ProNauticP series. Separate inverter maybe a good one like Samlex. Then a transfer switch. All these devices have parts that fail. I would not want to replace everything because one device fails. Well, I guess you could buy the cheap set and not worry. It would be cheap to replace. Cheap ones couldn't hurt anything. What do you think, John61?

 

[John61CT]

Yes I prefer separate, unless Victron PowerAssist is compelling.

And oversized inverters self-consume a lot of power, right-sized more efficient.

Rather than one big one, another strategy is several small ones, even 1:1 dedicated to each appliance, can save a lot of money, lots of loads are fine with cheap MSW rather than PSW.

Turn on and off as needed, save a lot of power.

My personal preference is go DC native as much as possible, AC only where really necessary.

Only connection to shore power is the mains charger.

But that's me, no desire for home appliances on board.