30amp/50amp

[Dodge_Boy]

I have a Cougar 29RKS with just a single roof A.C.. I was wondering if I could use a 30amp adapter and plug into a 30 amp plug. My understanding is the 50amp spec is if you have the second A.C. installed.

 

[snoobler]

I have a Cougar 29RKS with just a single roof A.C.. I was wondering if I could use a 30amp adapter and plug into a 30 amp plug. My understanding is the 50amp spec is if you have the second A.C. installed.

50A just means the unit is configured to consume more than 3600W (30A * 120V) total.

Microwave (1600W), A/C (1200-1400W) and W/H (1400-1500W) together would easily exceed that.

You can definitely do it, that's why those adapters exist, but you need to understand that you need to limit your consumption to stay under 3600W.

 

[RacerX-KEY]

Your 50 amp distribution panel uses both 120 v 50 amp legs to power different circuits in your coach. You can use a 30 amp to 50 amp dog bone to use a single 30 amp feed to power both sides of your panel but you are only providing 30 amps of 120v to your rig.

You can certainly run your rv with this set up however you may find that certain combinations will exceed your 30 amp supply. For instance if the microwave and converter are runn8ng when your ac starts up you can easily draw more than 30 amps….so you may need to turn off the AC if you want to use the microwave. Easy to manage but different than with the full 50 amp two 120 leg supply. 30 amp will supply at most 3600 watts. The 50 amp can supply up to 12,000 watts of power. Hairdryer can use 1500 watts. Microwave 900-1500watts. Single AC could use up to 1500 but double that on startup. You can see how they add up.

So yes, can run on 30 amps but just not everything at same time.

 

[RacerX-KEY]

50A just means the unit is configured to consume more than 3600W (30A * 120V) total.

Microwave (1600W), A/C (1200-1400W) and W/H (1400-1500W) together would easily exceed that.

You can definitely do it, that's why those adapters exist, but you need to understand that you need to limit your consumption to stay under 3600W.

Typing at the same time. …. Shorter answer is better. What he said!

 

[Max23]

I have a 30 amp system. I have run my microwave and A/C and water heater without even giving it a thought. I've never had an issue with anything. Do they all always run at the same time? Probably not, but maybe sometimes and again, my system is only set up for 30 amp and still has all the amenities that I use without questioning the system so take that for what it's worth.

 

[NH_Bulldog]

I would much rather carry our 30A power cord than the 50A behemoth that came with my camper. We have never had an issue with power with the smaller cord

 

[Dodge_Boy]

Thanks for the answers, I did call the dealer and talked to the service manager. He said basically the same as you guys, to just limit what you use. The trailer will be used to sleep in only with the A.C. only running and the frig on gas only. I'll tell them no microwave.

 

[DutchmenSport]

If you exceed the 30 amp limit, the only thing that is going to happen is the breaker at the power poll (or breaker box) is going to pop, killing power to the entire camper. It absolutely will not hurt the camper itself to exceed the 30 amps.

If the breaker pops, then before flipping the breaker back on, turn something off inside the camper so the total electric draw is under the 30 amps again. Flip the breaker at the power pole and all is well again.

That's ALL that's going to happen. No damage to anything.

 

[snoobler]

Thanks for the answers, I did call the dealer and talked to the service manager. He said basically the same as you guys, to just limit what you use. The trailer will be used to sleep in only with the A.C. only running and the frig on gas only. I'll tell them no microwave.

Typical fridge heating element is only 300-400W, so if it's just A/C at night, I'd consider saving the propane and running the fridge on AC/Auto.

Microwaves are horribly inefficient. A 1000W microwave actually consumes 1500-1600W. If it's a lower power microwave like a 700W, those use about 1100W. Using them on lower power doesn't help because 50% power just means run it at 100% power 50% of the time. It's actually worse, because each power cycle means the microwave is hammering the source with surge startup current.

Watch out for coffeemakers too. Your typical paper filter cheap-o is about 900-1000W. A Keurig or other single serving machine is closer to 1300-1400W.

Basically, you're good with two of the following:

A/C
Microwave
Coffeemaker
Water heater
Resistance heater (like my Big Sky's "fireplace")

With two of those running, you can also use your fridge in AC mode, but you won't have a lot leftover.

DC loads usually aren't an issue, but they do add to the total since your DC loads are ultimately supplied by the converter drawing AC power.

Breakers don't blow instantly when they hit their rated current. Short excursions at and slightly above the 30A rating may not trigger the breaker for several seconds or even a few minutes, so you likely have some margin for error if you realize you're running 3 high drain items.

If you exceed the 30 amp limit, the only thing that is going to happen is the breaker at the power poll (or breaker box) is going to pop, killing power to the entire camper. It absolutely will not hurt the camper itself to exceed the 30 amps.

If the breaker pops, then before flipping the breaker back on, turn something off inside the camper so the total electric draw is under the 30 amps again. Flip the breaker at the power pole and all is well again.

That's ALL that's going to happen. No damage to anything.

This is true, but managing the power and avoiding the disconnect is easier on people and equipment. Breakers that are regularly tripped trip at progressively lower current until they become unable to deliver rated current and eventually become useless as they can only deliver a small fraction of their rated current. Yeah, not your breaker, but you might be the next guy on that pedestal that won't deliver 30A.

 

[Dodge_Boy]

Okay, so I have been doing some research and I'm going to install a Safe Start RV AC Unit when I figure out what AC unit I have.


Basically it is a capacitor to reduce the load from the AC unit when it starts. The video I watched showed the typical draw at start up is 15 amps for a few seconds, with a running draw of of 5 amps. After installing the safe start unit the amp draw at start was under 9 with the running draw of 5 amps. By reducing the start draw you not only reduce the high start draw and you will also help prolong the life of your AC unit and or units. If we add the second ACI will also install a safe start unit on that AC also.

 

[snoobler]

Okay, so I have been doing some research and I'm going to install a Safe Start RV AC Unit when I figure out what AC unit I have.


Basically it is a capacitor to reduce the load from the AC unit when it starts. The video I watched showed the typical draw at start up is 15 amps for a few seconds, with a running draw of of 5 amps. After installing the safe start unit the amp draw at start was under 9 with the running draw of 5 amps. By reducing the start draw you not only reduce the high start draw and you will also help prolong the life of your AC unit and or units. If we add the second ACI will also install a safe start unit on that AC also.

If you're running on shore, it's not needed. Shore breakers are designed to deal with the surge associated with compressor start. Surge is typically about 5X run, but it's for a brief period. It will wreak havoc on inverters and generators, but the grid is like the Honey Badger. It don't care.

A capacitor added to the system is a "hard start". Basically, the capacitor provides additional reserve for the surge which reduces the pull from the source a little bit.

Microair and others make a soft starter - a piece of electronics that regulates how much current the unit is allowed to draw. They're very useful and effective.

Concerning your numbers, they seem off. Your typical 12-15kBTU/hr rooftop A/C is going to draw around 10A with a momentary surge in the 40-60A range.

 

[Rhagfo]

I would much rather carry our 30A power cord than the 50A behemoth that came with my camper. We have never had an issue with power with the smaller cord

Well we solved that issue, by making our own power cord out of 6/4 SOOW electrical cord. This cable uses rubber insulation and is lighter, and far more flexible than the standard issue power cord. It is so light and flexible that our 40' cord coils into a 3 gallon bucket. My hand is for scale not to hold the cable down.

 

[NH_Bulldog]

Thanks Russ, I have been looking for 6/3 & 8/1 SOOW cord to match the factory cord but that seems to be next to impossible to locate (or when I can find it, exceptionally expensive) so I am going to order some 6/4 SOOW and cord ends to build mine (was thinking 40’).

So far this year, all of our camping has been at 30A sites with one actually only having 20A. For that one, we just used a 25’ 12ga power cord. We do have MicroAir SoftStarts, and have had no issue running one 15k AC even on the 20A service (Amps peak at around 11.3A on compressor start).

 

[Rhagfo]

Thanks Russ, I have been looking for 6/3 & 8/1 SOOW cord to match the factory cord but that seems to be next to impossible to locate (or when I can find it, exceptionally expensive) so I am going to order some 6/4 SOOW and cord ends to build mine (was thinking 40’).

So far this year, all of our camping has been at 30A sites with one actually only having 20A. For that one, we just used a 25’ 12ga power cord. We do have MicroAir SoftStarts, and have had no issue running one 15k AC even on the 20A service (Amps peak at around 11.3A on compressor start).

Well once you get it made you will love it. We full time host in Oregon, we host in the Cascades foothills in winter, coiling up the power cord at 32 degrees, is just as easy as the 80 degrees!

 

[Dodge_Boy]

Well once you get it made you will love it. We full time host in Oregon, we host in the Cascades foothills in winter, coiling up the power cord at 32 degrees, is just as easy as the 80 degrees!

Russ, what does the 8/1 stand for? And wouldn't you need 6/4 or 6/3 + ground? Or did you make up a cord for a 30 amp plug?

 

[workinonit]

8/1 is 8 AWG single conductor wire. My Alpine is wired with 6/4 SO, pretty common cable that can be found anywhere.

 

[Rhagfo]

8/1 is 8 AWG single conductor wire. My Alpine is wired with 6/4 SO, pretty common cable that can be found anywhere.

I agree, you can run the ground one size smaller, but much easier to find straight 6/4 cable.