30 amp extension cord

[rbourdage]

Is there a concern about using a 25' extension cord with my 25' 30 amp shore power cord . Is a total of 50' create a potential electrical problem due to the length of the 2 cords. Sometimes I need to use both to reach the electrical hookup.
Also is there a concern plugging the 30 amp power cord to a 50 amp supply with a 50 amp adapter causing damage to the electrical system in the trailer

[azflycaster]

As long as the extension is of sufficient quality to handle the load, you should have no problem. I use a 25 ft extension at home since my plug it too far away.

Using 50 amp service with an adapter should not be an issue since the trailer has a 30 amp breaker for protection.

[Jammer]

Originally Posted by rbourdage

Is there a concern about using a 25' extension cord with my 25' 30 amp shore power cord . Is a total of 50' create a potential electrical problem due to the length of the 2 cords. Sometimes I need to use both to reach the electrical hookup.

There's nothing wrong with using an extension cord when you need it. There will be some voltage drop, but nothing significant.

I carry a 50' 30a extension cord and a 100' 20a extension cord. I rarely use them, but when they are necesary, well, they're necessary.

Also is there a concern plugging the 30 amp power cord to a 50 amp supply with a 50 amp adapter causing damage to the electrical system in the trailer

Nope, find something else to worry about

[SStar]

One of the guys that I RV with says that you should have at least a 10 gauge extension cord to carry the amperage without getting hot. I have a 25' 10 gauge cord that I use occasionally, never had a problem.

[J. Morgan]

I have used two 25' cords, 50', no problem.

In reality, in regular daily use , if a person doesn't run two space heaters at a time, (or a hair dryer and the a /c at the same time), it is generally rare that a camper with only one a/c will draw more than half of those 30 allocated amps but for brief periods.

[NevadaGeo]

A lot of air conditioners want 30 amps to run, or at least to start. Mine shuts down if it doesn't have 30 amps, which means using 10 gauge wire. and in my case I have to fire up the noisy generator if I want to test the air conditioner cause I only have a 25 amp circuit out back with 12 gauge wire.
Check your cord ends, the #10 wire won't get hot but the ends might only be good for 20 amp.

[J. Morgan]

I don't know, my 40 year old unit will run all night and all day on a 15 amp breaker, but not with a hair dryer too.

[NevadaGeo]

Originally Posted by J. Morgan

I don't know, my 40 year old unit will run all night and all day on a 15 amp breaker, but not with a hair dryer too.

And others will burn up the compressor with less than 30 amp. Which would you advise, tell them to go for 15 amp and try it, see if they let the smoke out? Or caution that a lot of air conditioners need 30 amps.
Out

[J. Morgan]

if the compressor needs more that the 15 amp circuit breaker can deliver it will trip the circuit.

A circuit breaker isn't analog, it is digital. A one or a zero, nothing in between.

[J. Morgan]

Anyway, my point was to illustrate that most campers rarely use all of a 30 amp service and when they do it is only briefly, to the end that a longish extension cord, properly sized, is not going to be an issue really.

[scamp]

Originally Posted by J. Morgan

Anyway, my point was to illustrate that most campers rarely use all of a 30 amp service and when they do it is only briefly, to the end that a longish extension cord, properly sized, is not going to be an issue really.

This is true ,but people don't think when making toast ,and coffee at the same time your now at maximum of a 30amp circuit if you turn on something else ,like if a,c went on or hot water heater turned (when on electric ) or if microwave was used ,the main breaker will trip, I think the rv industry needs to get up to speed and make all r.v. 50 amp service plus all campgrounds should offer 15amps service for tents or rv under 16 foot and 50amps service for all others ,don't get me wrong I'm very energy conscious ( I have solar at home ) but I believe in doing it right . (Today with all the electric gadgets ) Morgan made some good points you can safely use a extension cord but it all depends on the continuous power used , people need to learn to read labels on appliances, and remember watts =volts x amps and on some startup appliances like a.c compressors they can take more then what label says sometimes double or more.

[xrvr]

The only cord to use is a ready made 30 amp cord, not a lesser cord used with an adaptor. Jim

[RLS]

You learn what to use and not at the same time when plugged into a 30 amp breaker cause it will trip it when you try to use to much. Well, if you use the 50 amp breaker, that does not happen and you WILL burn (melt) the end plug ask me how I know So yes, you can use the 50 amp breaker with an adapter, but still be careful of what you have turned on.

[Ultradog]

I have been running my AS for 10 years on a 50' 10 ga extension cord.
Only way I can have it parked under the tree and still reach the power pole.
About the only time it could be an issue is when you are running the AC.
But I do pay attention and don't run the AC - and the fridge on electric - and a lot of lights at the same time.

[overlander63]

Most modern air conditioners draw 18 amps to start, and 12-14 amps to run. The problem with longer cords with multiple connections is voltage drop over distance, and through mechanical connections (plugs).
Electrons travel over the outside of the wire, so a thicker wire will carry more electrons, and thus more current. The voltage drop will manifest itself as increased amperage and heat generated. Amps low=volts high, and volts low=amps high. The lowered voltage through thinner, longer runs of wire, with attending voltage loss, is what causes problems such as burning up compressor motors.
So, long-winded response short, as long as the extension cord is large enough to carry the load over the entire run of the connection, you should have no problem.

[SL4BLLT]

As I purchased a 50' 20A HD extension cord last night at Lowes, the one thing I forgot to do was to check the forums and here is the discussion.
We just installed a new Duotherm 15K HP and it will run on an extension cord both AC and heat as long as there is nothing else on the house circuit.
However when I went to turn on the electric function of the A/S refrigerator, the house breaker tripped (15A service). So, there I figured I need to find a 20A service if I wanted to use the electric fridge, not gas while parked at the house.
We also did away with all of the 1156 light bulbs and replaced them with 18 LED puck style lights, and LED equivalent bulbs in reading, mirror lights and rear lights. Side-marker lights are next. Not only was there a huge drop in electric load/demand, but the heat that these 1156 bulbs produced was reduced. This was a 2-year project of buying them and then getting them installed.
I also found this electric flow calculator within this link. Don't know if it will help, but it does give the numbers as Terry stated above based on wire gauge and distance.

American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies and wire breaking strength

I'm for sure getting smarter in these areas thanks to these types of discussions.

SL4BLLT

[idroba]

In general, a 30' #10 wire extension cord will not be the real issue, it is the connectors (plug and socket) at the ends of both the AS and the extension cord. By in large, most of the older AS units with the fixed cords have molded plugs on the end. After a time, those plugs become damaged, either mechanically electrically and no longer fit tight when plugged in, or due to poor outlets may have over heated and the prongs out of place slightly, or corroded. I also have cut old ones apart and found the original wire to prong connections made poorly or damaged.

The same thing happens on the extension cord, but the worst is the molded outlet end. It often does not make good contact at all with the trailer plug resulting in high resistance and overheating (and voltage drop). Then the final end plug which goes into the campground outlet has another molded plug, and the outlets are very commonly worn themselves and are another high resistance point.

So, I doubt you will really find the #10 wire to be the problem on a 30 amp system, but the connectors, plugs and outlets, can really cause issues. This can affect both the starting current draw of the AC and the overall voltage drop of the system of cords and plugs you use.

I don't have a real recommendation for a solution other than look for really high quality cord sets, with good plugs and outlets, or make up you own with quality components. Typical extension cord sets available at Wal mart and common RV store stock are not very good over time. Again, the molded outlets seem to be the worst offenders. I have replaced some with metal boxes holding high quality RV outlets that really grip the plug ends of the RV. If your trailer plug is getting tired, with any signs of loose pins or melting at all, replace it with a good quality RV plug (and they are not easy to find).

And complain to the campground owners who don't keep their 30 amp outlets replaced often enough and are loose and worn out. They often will cause your RV plug to melt, if it is a molded on one, because of the poor connection at the post.