Power Sag/Current Issues at Seasonal Site

[ryankenn]

We are in our first year at a seasonal site we think we will be staying at long term. Everything is great, but the power. We only have a small Jayco 16XRB but even its 8K Btu AC and fridge prove challenging.

I haven't had my meter on it yet but you can tell by the sounds of the fans or AC that either the voltage droops badly or the run on the 12 wire from the looks of it is so long current isn't being delivered as fast as its demanded. Depending on neighboring usage fans will start slow and ramp up.

I am looking for ideas on how to combat this? I have setup a solar array at home before, but I don't know what to search for in terms of a device like an MPPT controller, but instead of the panels, that input is line. I would like a bank of batteries to be controlled and charged by the pole 120V (or sagged level its at) and the controller to supplement the supply using the batteries and an inverter so the trailer has steady voltage and good current delivery.

I had hoped a device existed but in searching it may be more practical to just have the site run a charging system that keeps a bank of batteries full and I draw from an inverter.

Thoughts or experience here would be great. The Norcold has already had one control fault leaving us with spoiled food and the neighbour has had some HW boards and the in trailer 12V inverter board fold because of the same issues and I want to avoid this.

Thanks!
Ryan

[ryankenn]

Yeah I never thought about the demands of the Autoformer. The most I draw is about 12A's, so I had hoped that the autoformer even though its "30A" if I never drew close to that it could work from 20A to create my 120V.

I have found a few inverter/chargers but they all feature auto transfer, so if AC is present it wants to use it. I need to fully isolate, so I may need two seperate units to do it. Renogy seems to have a few options, and a good price ($350) for 12V/200Ah batteries. Because I'd be continuously charging I could probably get away with a smaller bank than needing to run on batteries with no charging or small solar charging.

[time2roll]

Yes that park was built before A/C was even used let alone common. 100 volts is too low, 20 amp service is inadequate for the Autoformer. I would be looking at that battery charger, large battery and 3000w inverter. I would probably be going 24 volt lithium battery and GoPower inverter but that is your call. Since you have 20a power I would skip the solar.

[Ivylog]

At $3K and after 50 years, the park needs to run a larger service to your panel and you need a minimum of a 20A breaker and a #10 feed to your camper IF the voltage at the panel is 110 under your max load and the neighbors.

[ryankenn]

Well I have some results from the weekend.

I found our sub panel, which is in my spot has (4) 20A breakers. There is 10AWG household wire direct buried feeding each trailer. Mine is about 15' from that box to the pole. That panel is fed from a single 40A breaker in a panel about 250' away on 8AWG.

I sort of operated the trailer normally. I put the fridge on electricity, had the A/C on Econo and lived normally. When I heard the compressor straining I would check the voltage.

On average, with nothing really running its about 117V. With the A/C running its fan only and things like the TV and lights on it hovers around 110V. When the A/C kicks in it drops to 100V.

As an experiment (which we don't normally do) I ran the toaster with the A/C compressor going and it drops all the way to 94.5V. I normally turn off the A/C for running the toaster, microwave or coffee maker.

We have yet to ever pop a breaker, while my neighbor's all have but have significantly bigger trailers with rooftop 13.5K units, and one guy has a traditional bar sized fridge on his deck.

So far the only downside for me is the Norcold fridge has flaked twice while on A/C. Once it showed the error on the display and the reboot fixed it. The second time (this weekend) overnight it just stopped cooling on A/C despite the display thinking it was. Switching to propane solved the issue and overall the trailer seemed much happier in that config.

So, is the Autoformer the way to go? I think my max amp draw would be 12-13A, so I assume its boosting would mean I would be drawing 15-16A to the pole so I should be OK still not popping the breaker. It wouldn't be a magic fix since I did see as low as 94.5V which means with help the voltage low would be 103-104V and normally the trailer would run at worst 110V with the booster.

I am leaning that way but want input.

Here is a pic of the mess at the local box, and one of our spot.

[wa8yxm]

12 ga is 20 amp for less than 100 feet
30 amp and a long run 8 ga or larger is required
That is the issue

NOTE that sucking More amps by using an Autoformer to boost the voltage (By booting amps park side) can cause that 12ga to melt..> The park won't be pleased if they see you have an autoformer..

So,, Install it, inside where it can not be seen.
(That is what I did)

[dougrainer]

ryankenn wrote:
Oh, and yes to that last reply, my site is supposed to be a 120V/30A site, but I can see the pole to the sub is only 12AWG, and that sub feeds three sites and its feed wire looks like 10AWG and has quite a long run to the next sub panel that feeds it, which is totally substandard I am sure. The park is over 50 years old, so its not super surprising.

You just found your problem. For a 30 amp service of less than 150 ft, 10 gauge is good. Longer you really need 8 gauge. Now, you state 3 campsites are powered by possible 10 gauge. So having 12 gauge supplying YOUR plug is way inadequate. 12 gauge is what is required JUST FOR the RV AC circuit wire. So, as with some older not updated parks, you have loss of line voltage and THAT WILL cause problems and failures of YOUR appliances. Your refer pulls less than 2.5 amps on AC. BUT, your roof AC will pull (8k) about 7 to 9 amps depending on the outside temp. Doug

[ryankenn]

Oh, and yes to that last reply, my site is supposed to be a 120V/30A site, but I can see the pole to the sub is only 12AWG, and that sub feeds three sites and its feed wire looks like 10AWG and has quite a long run to the next sub panel that feeds it, which is totally substandard I am sure. The park is over 50 years old, so its not super surprising.

[ryankenn]

WOW! This is a forum I can appreciate, thanks for all the replies!

First step I guess is I will check how bad the voltage is this weekend.

For some of the other points:

-its close to our house (less than 20mins) so we like the flexibility of being able to just go home should the weather sour
-its $3K a season CAD. With Covid a 1/2 acre lake front vacant piece of land is now $350K and up here, and could be 1.5 hours away. We figure at our age this will be our lake front property, and the shortcomings I am willing to work around.
- the park is huge, and we each have large parcel, trailers aren't stacked. We like our spot as it has a water view out front, and water access in the rear, we don't want to move
- the park owner is flexible. He has already kicked in for landscaping and is open to put money towards the issue. For him to rewire I couldn't even imagine. Our sub is shared by three spots, and I would estimate it is 750 feet from the large sub that feed our side of the park.

It gets hot here, and being a Hybrid, even with the Popout Gizmos the week we left the A/C off it was 40C inside and took hours to cool down with the little window shaker style 8K. We leave it on Econo mode so it just keeps the trailer cool.

I have moved the fridge to Propane already, but even just the A/C all on its own is enough to affect the voltage. We have not popped a breaker yet but I will be curious to see how bad it is the weekend when I measure.

It sounds like if the droop isn't horrible, the Autoformer would be the best bet. If its horrendous my initial plan was to let the site 120v run a charger that accepts a wide input voltage to charge a bank of 2 or 3 200AH deep cycle batteries, and then use a 3000W inverter to run the entire trailer. That cost would be around $1500 I think, and in Canada that autoformer is $700 anyways so its not the end of the world.

I was just curious if it was hard or possible to use batteries to compensate real time but I guess that would be pricey.

Having used MPPT stuff for Solar at my house I understand its not the same, but such as this diagram



I was hopeful a controller existed that would take a 90-230VAC input where the solar panels on an MPPT go, but perform the same functions everywhere else, charging the batteries, feeding the inverter etc. Basically I would totally isolate myself from the park voltage and only use it to run the charger to charge the batteries.

Thanks for all the input, this has been great for a first post. Hopefully the droop is autoformer fixable then this would be simple!

[time2roll]

ryankenn wrote:
I haven't had my meter on it yet but you can tell by the sounds of the fans or AC that either the voltage droops badly or the run on the 12 wire from the looks of it is so long current isn't being delivered as fast as its demanded. Depending on neighboring usage fans will start slow and ramp up.

Is that #12 wire feeding what service? 20, 30, 50 amps? Is the RV 30 amps?
Yes put a voltmeter on the supply before you plug in and again with a few items running.
Are you willing to go without A/C?

[dougrainer]

You state 12 volt. The Roof AC requires only 12 volts(milliamp) to operate the AC controls. If you have roof top AC controls, then NO 12 Volt is used by the AC. Fluxcuating 120 voltage CANNOT be easily compensated. That type problem will cause various problems on your various appliances. Doug

[Lwiddis]

Your situation demands an autoformer to prevent damage to your RV.

[schlep1967]

You have been given options that are going to cost you money for a problem that is not yours. The problem is the parks to deal with. I would tell them to provide you with the proper electric or you will expect a refund of your money for the rest of the year and you will be leaving. Staying in the situation you are in and doing nothing is also going to cost you money. Low voltage will kill your electrical items in your camper.

[valhalla360]

One other option would be to upgrade the battery charger and install an inverter sized to accommodate the loads (not cheap but effective)

Get a 200amp @12v charger, a moderate size battery bank and a 3500w (peak output) inverter.
- The charger will be capable of putting out around 2400w.
- The battery storage can provide a boost for start up loads (continuous loads are typically much lower. They are only for a second or so...so not an issue topping the battery bank back up.
- The inverter is big enough to cover the start up loads.

I've seen this used on boats where they travel between 120v @ 60hz and 240v @ 50hz. They get a battery charger that can accept either input voltage and the inverter is selected to provide what the onboard appliances require.

But assuming it's not really bad, the autoformer should handle the issue.

[valhalla360]

theoldwizard1 wrote:
Some careful research MIGHT locate an inverter that will ADD power to your circuits ! Then a good solar and battery setup would be another solution.

They do have inverters that can merge with shore power but MOST inverters don't and the ones that do are expensive.

You CAN'T simply wire the inverter into the shore power circuit simultaneous with the shore power cable. It needs electronics that line up the sine waves or you can cause major problems.

[valhalla360]

wanderingaimlessly wrote:
In addition to Valhallah's comment, solar to charge the batteries, allowing you to turn the converter off can provide some help.
Otherwise, the Autoformer.

But also keep in mind, unless you let the battery get run way down and you have a big high amperage charger, this is really nibbling at the edge of the AC voltage problem.