120V / ~15AMP ac for a scamp 13

[dcs02d]

Hi all,

I'm slated to pick up a new scamp 13 in March. I'd love a used one but good luck finding one

I'd really like to be able to run the AC via a standard outlet so that when I'm visiting in-laws I can stay comfortably in my camper at night. Good campers make good inlaws!

I'm concerned that the stock rooftop AC compressor will run only with the 30AMP connection.

Assuming I'm careful and run only the AC can I put a 30amp to 15 amp converter on the electric and run just the AC?

If not can someone recommend an alternative AC setup with a portable that will run on a standard household ~15 amp outlet?

Thanks.
Don

[Dan Meyer]

I converted my Scamp 16 to run exclusively on 15 amps years ago, and never looked back. My Scamp is 16 years old, and so is the roof A/C. Everything is working quite nicely.

--Dan Meyer
http://scamp.n0kfb.org/

[gordon2]

I recommend you stick with the A/C manufactures recommendations. In most cases on RV A/C units I think that is a 20 amp supply. So supply your trailer with 20 amp rated supply from the source to the A/C (wiring, 20 amp adapters plugged into 20 amp service and not 15 amp, etc.) and run almost nothing else in the camper except LED lights when the A/C is on.

You will soon see other replies that say otherwise.. YMMV and its your money. But remember that having more amps available than your need is insurance... having less than you need could be an insurance claim.

[Darwin Maring]

We have always used a 12 Gauge extension cord to plug into the campground and home 15Amp circuit. The only problem is: We can not run the AC and Microwave at the same time. So, we turn off the AC during the 2 1/2 minutes it takes to pop the corn then turn the AC back on.

[dcs02d]

Originally Posted by Darwin Maring

We have always used a 12 Gauge extension cord to plug into the campground and home 15Amp circuit. The only problem is: We can not run the AC and Microwave at the same time. So, we turn off the AC during the 2 1/2 minutes it takes to pop the corn then turn the AC back on.

I guess I just need to call scamp and find out the exact model of the AC to see what amperage it needs... if it's under 15 I guess I can get the 30 amp to 15 converter and a thick short chord and assuming nothing else is running I should be fine?

Just looking to run the AC while I sleep

[steve dunham]

Voltage / Voltage drop / low voltage is more of an issue than amperage / circuit ampaciry
A 20 amp circuit at 100 VAC is more damaging to your A/C than a 15 amp circuit at 120 VAC.
As Darwin noted , you need to use a properly sized ( AWG) extension cord to limit voltage drop
Motors don't like low voltage especially when starting under load.

[gordon2]

Originally Posted by steve dunham

Voltage / Voltage drop / low voltage is more of an issue than amperage / circuit ampaciry
A 20 amp circuit at 100 VAC is more damaging to your A/C than a 15 amp circuit at 120 VAC.....

A good point, and why I also use a Progressive Industries EMSHW30C Surge Protector that shuts off the power when the voltage drops to a level unsafe for the A/C. It did just that twice when I was at a site with substandard power last summer. I think that it is a very good addition when you are dealing with different power sources that might not be always adequate.


If one uses a 20 amp adapter (like the one I linked to) and plugs it into a properly functioning 20 amp outlet using the 30 amp shore power cord supplied with the camper, then voltage drop while running only the standard A/C will not be a problem. The use of extension cords for longer length should be approached with caution. I would guess that most campgrounds have some combination of 50, 30 and 15 amp outlets but not often 20 amp outlets but at home I use a 20 amp outlet as I have described.

[dcs02d]

It looks like what I might want to do is order the scamp without an AC and have the AC installed after the fact.

Is the Dometic Penguin II the lowest power roof top AC I can get?

[ravensrest]

We have a new Scamp 13 with factory A/C, and run ours on 15 amps routinely. We simply use a 30A-15A adapter. However, the A/C is the ONLY thing you will be able to run. Turn on the master and A/C circuit breakers and NOTHING else. You should have no problems.
BS

[steve dunham]

Originally Posted by gordon2

A good point, and why I also use a Progressive Industries EMSHW30C Surge Protector that shuts off the power when the voltage drops to a level unsafe for the A/C. It did just that twice when I was at a site with substandard power last summer. I think that it is a very good addition when you are dealing with different power sources that might not be always adequate.


If one uses a 20 amp adapter (like the one I linked to) and plugs it into a properly functioning 20 amp outlet using the 30 amp shore power cord supplied with the camper, then voltage drop while running only the standard A/C will not be a problem. The use of extension cords for longer length should be approached with caution. I would guess that most campgrounds have some combination of 50, 30 and 15 amp outlets but not often 20 amp outlets but at home I use a 20 amp outlet as I have described.

The NEC allows both 15 & 20 amp receptacles to be installed on 20 amp circuits . The NEC requires 2--20 amp circuits in residential kitchens yet the receptacles on those circuits are rated at 15 amps.
In campgrounds the pedestal is often fed with 50 /60 amp conductors / feeders which feed the 50 , 30 & 20 amp circuits of the pedestal.
Again the issue is not whether the receptacle is 15 or 20 amps but the size of the feeder , total length of the feeder conductors and the load imposed upon those conductors.
In many older campgrounds the feeder serves multiple pedestal and the conductors are not sized properly to compensate for voltage drop when loaded at 100%
Older campgrounds were not designed for trailers with A/C

Feeders are also allowed to be derated because it is assumed that all of the pedestal will not be fully loaded at the same time .
Now that most trailers have A/C and numerous electrical appliances ,the electrical systems in many campgrounds are inadequate . IE : Voltage Drop and Feeders being overloaded.
A surge protector does not solve this problem , it only reacts to the symptoms.
The issues with low voltage at the pedestal can not be solved by the trailer owner. If the system voltage is low , a heavier extension cord or a surge protector will not solve the problem,
An inadequately sized extension cord will only make the problem worse.
Even modern campgrounds have issues because many Class A motor homes now have 2 A/C units.
If campgrounds were wired to handle the worst case scenario
of being loaded to 100% continuously , the cost to install / maintain the system would be extremely high and would lead to higher camping fees.
There is no such thing as a FREE lunch.

[dcs02d]

I got a pointer to this device...

Micro-Air - Products

I'm inclined now to have the AC installed after I get it. Dometic has a lower profile penguin and I'm guessing scamp won't let me swap out for a different AC model. Is it really better to just have scamp install it? I'd prefer not to have my new camper butchered by a local repair shop

[DuaneQ]

Originally Posted by steve dunham

Voltage / Voltage drop / low voltage is more of an issue than amperage / circuit ampaciry
A 20 amp circuit at 100 VAC is more damaging to your A/C than a 15 amp circuit at 120 VAC.
As Darwin noted , you need to use a properly sized ( AWG) extension cord to limit voltage drop
Motors don't like low voltage especially when starting under load.

Steve hit the nail on the head. Voltage drop ain't good. I like to use this just to check for voltage drop etc. Good for when your equipment is a plug in and not really for hard wired equipment but still could be used with some effort messing with the wiring. Use it at home and bring it along in the RV.

https://www.amazon.com/P3-P4400-Elec...ords=killawatt

[steve dunham]

Low voltage / voltage drop is not much of an issue with resistive loads. Incandescent lamps , toaster , electric fry pans ,etc will operate on a lower voltage , they just don't work at 100 %.
The toaster will still toast , it will just take longer .
Inductive loads (Motors ) do not like low voltage
Years ago ( before LED's) , we would install 230 VAC incandescent lamps in 120 VAC lighting fixtures. The bulbs had a lower lumen output but they lasted about 10 times longer .

[DuaneQ]

Originally Posted by steve dunham

Low voltage / voltage drop is not much of an issue with resistive loads. Incandescent lamps , toaster , electric fry pans ,etc will operate on a lower voltage , they just don't work at 100 %.
The toaster will still toast , it will just take longer .
Inductive loads (Motors ) do not like low voltage
Years ago ( before LED's) , we would install 230 VAC incandescent lamps in 120 VAC lighting fixtures. The bulbs had a lower lumen output but they lasted about 10 times longer .

Initial question was about an AC unit. Yes I agree that motors and other inductive loads do not like low voltage. And I agree that resistive loads are not much of a concern if you don't mind wasting power loosing it on extension cords etc. Some basic test equipment is necessary if someone doesn't want to learn how to use a multi meter.

When I worked for and electrical contractor as an electrician we used 130 volt bulbs in places that were hard to access.

https://www.youtube.com/watch?v=Wmhg7kMWlMQ

[steve dunham]

Originally Posted by DuaneQ

Initial question was about an AC unit. Yes I agree that motors and other inductive loads do not like low voltage. And I agree that resistive loads are not much of a concern if you don't mind wasting power loosing it on extension cords etc. Some basic test equipment is necessary if someone doesn't want to learn how to use a multi meter.

When I worked for and electrical contractor as an electrician we used 130 volt bulbs in places that were hard to access.

Buy a "WIGGY" cheap ,easy to use , good for a range of voltages ,
hard to damage , no dials to play with and has a short learning curve . I still have the one I bought when I started my apprenticeship in 1970. Still works as good as new.
We used a fire alarm horn to trace 120 volt AC circuits ,when the horn went off you hit the right breaker.
We screwed an Edison based lamp into Edison bases fuse holders to test for short circuits
We always used a UL approved meter to test for higher voltages
( WIGGY, Fluke , Harp ,Tic Tracer , Amprobe )
If you don't know how to properly use a multimeter or any meter for that matter then maybe you shouldn't be messing around with electricity ? Just a thought.!!