15 AMP Shore Power question

[Tim Schafer]

We are currently camping at a flea market and they only provide 15amp power connections.  I have my main power cable feeding thru a 50 to 30 amp adapter and then a 30 to 15 amp adapter.  When plugged in my invertor/charger is not showing AC input.  My aqua hot tho is getting power.

Does anyone know if this is normal, or does this sound like something is backwards.  I expected the invertor to get power and to have to run the diesel burner to get heat.

My RV guy recently replaced my transfer switch, could he have reversed the 110 legs on the cable to have caused this? or is this the way it should be operating.

This past weekend when plugged in to 50 amp, everything worked.

Thanks for any info you can provide.

Tim & Ann

[Tim Schafer]

NM, operator error.  Too embarrassed to even post what I did......

[Fred Brooks]

                Hi Tim,

        Not really sure what the error was. Most common issue is failure to turn a bunch of stuff off like the electric water heater, move the refer over to gas, and turn the power share on the charger down to 5 or 10 amps. Even then it is difficult to run a 100 amp coach on 15 amps. Regards, Fred

[Bill Sprague]

Another approach to 15 amp camping is to "dry camp" and use a standard 12 automotive charger hooked directly to your house batteries.  The idea is to set up so your inverter is providing the coach 120 system.   Such chargers can't exceed a 15 amp draw, so breakers don't trip when you turn something on.  I think most only draw about 8 amps.  And it isolates your expensive motorhome system from a potentially weak grid that may have low voltage, spikes, polarity problems, weak ground, etc.   When I've done it, I've seen the batteries drain a little faster than the charger can keep up during evening hours with TV watching and lights being used.  By morning they would be near full charge. 

I didn't invent this idea.  It came from people who enjoy camping in Mexico where some parks have electrical systems that make coach owners nervous.  The idea is that if something "fries" it is a cheap and easy to replace charger, not an internal component of the motorhome.

[Tim Schafer]

We failed to actually plug the coach in to the cable....  I had the cable plugged into the power outlet at the campground, but each of us thought the other plugged the cable into the coach.

Unfortunately my aquahot doesn't have an electrical shut off other than the breaker.  We first encountered an issue trying to heat up some chicken in the microwave, I assumed that at least would run off the invertor, but apparently if the aquahot also runs off the invertor they don't like to run at the same time.

She plugged in the coffee pot this morning and that tripped the breaker at the feed.  So that we know will require the generator to run for.

I think the main reason we missed the cord issue tho was it was dark, and I was headed back to town, she was going to stay up there last night.  She discovered it this morning when she went out to unplug before starting the generator and determined it was already unplugged.

Once she plugged it in, the AC input light on the invertor did light up and it was showing quite a few amps as I'm sure it was recharging the batteries.

We'll see how it does today.  Hopefully between the 15amp in and the solar panels on the roof that it will keep the batteries up for any usage she does today.

Silly mistakes on our part, and part of learning to run a high amp coach off of a low amp circuit.

Tim & Ann

[Bill Sprague]

...... but apparently if the aquahot also runs off the invertor they don't like to run at the same time.

It is highly unlikely that the AquaHot electric element draws 120 from the inverter.  Nor will the A/C and laundry.  The only high amp load that does draw from the inverter may be the microwave.  A minute or two to heat something is OK.  Longer times will draw down the battery fast. 

The AquaHot will run on diesel with 12 volt house power.  120 is not needed.

The "trick" on 15 amps is to make sure the battery charger is not using more than it's "fair share".   If batteries are discharged our "smart" inverter/chargers can assume they have a full range of power and will immediattly go to work at full speed to get the batteries back to a full charge state.  On our Beaver that initial load could be as high at 20 or more amps.  It would gradually taper off but on a 15 amp supply, it would trip the shore supply breaker in seconds.  Inverter/Charger controls vary, but if you are on a 15 amp shore power, it is necessary to tell it your are through the control panel.  When we were on 15 amps (and I elected to not use an external charger), I would set the onboard inverter/charger to 10 amps max. 

Even with the 10 amp max, if I used the microwave it would add about 10 amps putting the 15 amp shore power breaker past its limit.   You can stay on 15 amp hookups a long time.  But, you can't use much of anything more than the TV because of the charger's "overhead". 

If you draw down your batteries and don't tame your inverter/charger to something less than 15 amps, you may have continuing trouble every time you restore the external 15 amps.   The supply breaker will continue to trip when the charger demands its initial load and you will never get the house batteries up.  Continued discharge may draw them down to a point of them being permanently damaged.

[Tim Schafer]

We have a freedom 20 inverter, the control panel is basically a display with an on off switch, there is no way to tell if how many amps its allowed to draw.

I'm sure the aqua hot started producing heat as soon as I turned the salesman switch on when we weren't plugged in.

If my mechanic reversed the 110 legs when he put in the new transfer switch, do you think that might cause the aqua hot to feed off the inverter?

It was showing 40 amp in use lastnight with only a TV and a few lights on? This was not while hooked to ac.

It did come down after I fired up the diesel burner on the aqua hot and got it up to temp.

I have one of the old style aqua hots with a single pump and just the one switch to turn on the diesel. No other controls or light panel.

Tim and Ann

[Jerry Emert]

We are currently camping at a flea market and they only provide 15amp power connections.  I have my main power cable feeding thru a 50 to 30 amp adapter and then a 30 to 15 amp adapter.  When plugged in my invertor/charger is not showing AC input.  My aqua hot tho is getting power.

Does anyone know if this is normal, or does this sound like something is backwards.  I expected the invertor to get power and to have to run the diesel burner to get heat.

My RV guy recently replaced my transfer switch, could he have reversed the 110 legs on the cable to have caused this? or is this the way it should be operating.

This past weekend when plugged in to 50 amp, everything worked.

Thanks for any info you can provide.

Tim & Ann

Never mind I didn't read far enough!

[Tim Schafer]

Another approach to 15 amp camping is to "dry camp" and use a standard 12 automotive charger hooked directly to your house batteries.  The idea is to set up so your inverter is providing the coach 120 system.   Such chargers can't exceed a 15 amp draw, so breakers don't trip when you turn something on.  I think most only draw about 8 amps.  And it isolates your expensive motorhome system from a potentially weak grid that may have low voltage, spikes, polarity problems, weak ground, etc.   When I've done it, I've seen the batteries drain a little faster than the charger can keep up during evening hours with TV watching and lights being used.  By morning they would be near full charge. 

I didn't invent this idea.  It came from people who enjoy camping in Mexico where some parks have electrical systems that make coach owners nervous.  The idea is that if something "fries" it is a cheap and easy to replace charger, not an internal component of the motorhome.

When using this method, do you put the charger on 2 or 10 amp?

And do you just leave it running on that setting the whole time you camp?  I have a 2/10/50 charger, and obviously I wouldn't want the 50amp option.

Tim & Ann

[Bill Sprague]

Another approach to 15 amp camping is to "dry camp" and use a standard 12 automotive charger hooked directly to your house batteries.  The idea is to set up so your inverter is providing the coach 120 system.   Such chargers can't exceed a 15 amp draw, so breakers don't trip when you turn something on.  I think most only draw about 8 amps.  And it isolates your expensive motorhome system from a potentially weak grid that may have low voltage, spikes, polarity problems, weak ground, etc.   When I've done it, I've seen the batteries drain a little faster than the charger can keep up during evening hours with TV watching and lights being used.  By morning they would be near full charge. 

I didn't invent this idea.  It came from people who enjoy camping in Mexico where some parks have electrical systems that make coach owners nervous.  The idea is that if something "fries" it is a cheap and easy to replace charger, not an internal component of the motorhome.

When using this method, do you put the charger on 2 or 10 amp?

And do you just leave it running on that setting the whole time you camp?  I have a 2/10/50 charger, and obviously I wouldn't want the 50amp option.

Tim & Ann

10 amp and 12 volt.  Make sure you clip the leads to the right battery posts.  And, I leave it running.  If it is an automatic charger it may shut off if the batteries get a full charge.  Then you would have to restart it.