Mysteries of mooching a hookup from residential system

[Cameron]

We're on a lengthy round-the-country trip with stops at all sorts of camp spots. Some are Harvest Host, some are Hipcamp, some are with friends/relatives in their driveway. (Boondocking is great too but this time of year we can't count on the solar panels to recharge enough.) The only time we get a 30a hookup is at an official campground. When possible with shore power we like to run a space heater (1500w high/750w low) because it gets rid of humidity/condensation. The mystery is what happens when when we plug into a residential 120 outlet (using and adapter). Sometimes it's great and we can run everything  (hot water tank, fridge, space heater). Sometimes we can't even use it to charge the batteries. During problems, the charger readout in the attic gives us an E 0 and a P4 (low voltage) and a reading of 104 to 117v (roughly). That's when the inverter turns on and off with a big "thunk". 

Oliver service tells me the problem is that there are likely other draws on that residential circuit I'm plugged into, and that the best bet is to us an outlet with a dedicated circuit, but I don't think most residential systems are wired that way. 

However, sometimes the readout shows less than 120v and everything works fine, including charging and running appliances. That's the mystery. I've adjusted the Xantrex settings down to 10a for incoming power and 50a for battery charging, but that doesn't seem to make a difference.

At this point I'm basically limiting my mooching to charge the batteries however much I can when my hookup voltage isn't fluctuating very much.

[Rivernerd]

Are you checking the voltage and amperage of the various 120V supply circuits you are "mooching" off of, with a multi-meter?  That may solve some of the mystery.  Many residential 120V circuits are overtaxed and cannot support the significant additional power demands of an Oliver Elite II. 

Do you carry a heavy-duty (like 10-gauge) extension cord in your Oliver?  When "mooching", I use a 10-gauge cord with a 30A adapter.

I also recommend checking for incorrect wiring with an inexpensive outlet tester before you plug in.  I have avoided some unpleasant surprises by checking unknown receptacles before plugging in, with one of these:

https://www.amazon.com/Receptacle-Tester-Klein-Tools-RT210/dp/B01AKX8L0M/ref=asc_df_B01AKX8L0M?mcid=4df224494ad63027958a05dc381a06a5&tag=hyprod-20&linkCode=df0&hvadid=693608794701&hvpos=&hvnetw=g&hvrand=5705870914769089309&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9029558&hvtargid=pla-498023562957&psc=1

[Tom and Doreen]

If your batteries are low your charger will draw a larger amount of current which will likely exceed a standard residential outlets current capability.   You can adjust the settings in your inverter / charger to lower the charger current.  This will require a longer time to recharge your batteries.  

[Cameron]

1 hour ago, Tom and Doreen said:

If your batteries are low your charger will draw a larger amount of current which will likely exceed a standard residential outlets current capability.   You can adjust the settings in your inverter / charger to lower the charger current.  This will require a longer time to recharge your batteries.  

Yes, I've adjusted the charger draw rate on the Xantrex app so as to not overtax the residential system. As we are often visiting someone for a couple days, the longer period needed to charge the batteries is not a problem.

[Cameron]

1 hour ago, Rivernerd said:

Are you checking the voltage and amperage of the various 120V supply circuits you are "mooching" off of, with a multi-meter?  That may solve some of the mystery.  Many residential 120V circuits are overtaxed and cannot support the significant additional power demands of an Oliver Elite II. 

Do you carry a heavy-duty (like 10-gauge) extension cord in your Oliver?  When "mooching", I use a 10-gauge cord with a 30A adapter.

I also recommend checking for incorrect wiring with an inexpensive outlet tester before you plug in.  I have avoided some unpleasant surprises by checking unknown receptacles before plugging in, with one of these:

https://www.amazon.com/Receptacle-Tester-Klein-Tools-RT210/dp/B01AKX8L0M/ref=asc_df_B01AKX8L0M?mcid=4df224494ad63027958a05dc381a06a5&tag=hyprod-20&linkCode=df0&hvadid=693608794701&hvpos=&hvnetw=g&hvrand=5705870914769089309&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9029558&hvtargid=pla-498023562957&psc=1

Yes, I have one of those testers you mentioned and on a couple of occasions learned that there was no ground, so using that outlet was definitely not going to work. However, even when plugged into the trailer, it didn't do any harm. The trailer's electronic system (surge protector, charger, etc.) seems to be designed well so as to not be damaged when I plug into an outlet with no ground.

Yes, I use a 10g extension cord with a 30a adaptor.

I haven't checked the outlets with my multimeter, I've only watched the readout in the attic. When the readout says it's only getting 105 amps, I know that it's game over for me on that outlet. But I've had the experience where later in the day I get a full 120v, and then I'm good.

 

[jd1923]

4 hours ago, Cameron said:

I've adjusted the Xantrex settings down to 10a for incoming power and 50a for battery charging, but that doesn't seem to make a difference.

Try bringing charge rate down to 20A and if "mooch docking" voltage is less than 115V I would not plug into that source at all. Run your fridge and OEM furnace on LP! 

[Snackchaser]

I’ll throw another theory into the pot:  This has the hallmarks of a high resistance connection such as loose fitting plug or broken wire.   These can change resistance with very little movement or vibration, and resistance means voltage drop.  A prime suspect would the 30 amp to 20 amp adapter, since the problem occurs when it’s being used.

While looking at your readout, have someone give the adapter connection, and the whole shore power cord, a good shaking to see if that's the cause.

Good luck and let us know what you find.

Cheers, Geoff

[Ronbrink]

@Cameron, I had the same problem at my storage facility, the Hughes Autoformer RV voltage booster I installed helped a lot! Setting the Xantrex charge rate lower, as others have suggested, is a helpful measure! 

Edited December 31, 2024 by Ronbrink

[CRM]

1 hour ago, Ronbrink said:

@Cameron, I had the same problem at my storage facility, the Hughes Autoformer RV voltage booster I installed helped a lot! 

Yep, every RV should have one. 

[Cameron]

On 12/31/2024 at 10:24 AM, Ronbrink said:

@Cameron, I had the same problem at my storage facility, the Hughes Autoformer RV voltage booster I installed helped a lot! Setting the Xantrex charge rate lower, as others have suggested, is a helpful measure! 

I've never even heard of a voltage booster, or seen one being used. It sounds like it would solve some of the problems I'm having, so I'm going to investigate some more. All of the stuff I'm seeing online is about using this at RV parks, rather than with a residential system. Would love to hear from others who have this booster.

[Ronbrink]

12 minutes ago, Cameron said:

All of the stuff I'm seeing online is about using this at RV parks, rather than with a residential system.

True, but the storage facility is full of RVs and boats plugged into the electrical system much like a park, I mainly installed for RV use when traveling, as marketed, but reaping benefit when in storage, as well. You are correct about residential systems, which are generally much more stable other than power outages,