How many extension cords can you string together?

Yes, but may be hard to run the A/C.

I would monitor the voltage while ht e AC is running. Shut it down if too low.
Also check all the connection points at the ext. cords from time to time for excess heat.

Hi,

You can run as much as you want but every additional foot will add to voltage drop. Monitor the voltage or get an autoformer.

I tried pretty much the same thing at a buddies cabin with #10 and #12 wire extensions. Bottom line is, glad I had my 3k Honda gen because it wouldn't pull my 13.5 air with everything else off.

It's one of those things you'll just have to try yourself to find out for sure.

ScottG wrote:
I would monitor the voltage while ht e AC is running. Shut it down if too low.

I have an AC Voltage Line Meter, so I will do that for sure

ScottG wrote:

Also check all the connection points at the ext. cords from time to time for excess heat.

I assume that excess heat at the connection points is a sign that the voltage is too low? That's one reason why I'm using a dogbone instead of those cheap adaptor plugs that DO get HOT.

pianotuna wrote:
or get an autoformer.

I've never heard of the autoformer. I did a quick google and found the Hughes Autoformer. Looks like a nice setup.

Electrical fires almost always occur at the junctions .
The heat generated by a poor connection is what does it .
Your connection would be out in the open and you can tell by feeling if the extra connection is not a tight fit .
A 30 amp cord requires # 10 guage wire .
That cord is the larger diameter just like the pigtail coming from your trailer .
Because # 10 guage 30 amp cable is so much more expensive and wieldy some try to extend their run with the more common 14 guage or 12 guage cord .
The problem is that at higher amperage flows the smallest diameter cord restricts the overall current flow .
The best solution is probably using only # 10 guage even if you have an extra junction .
Of course a single # 10 guage say 50 feet long would be the best solution .

jaycocreek wrote:
Bottom line is, glad I had my 3k Honda gen because it wouldn't pull my 13.5 air with everything else off.

I'm really tempted to get a 3K generator. Besides the travel trailer, it would come in handy for MANY uses.

Lowsuv wrote:

Of course a single # 10 guage say 50 feet long would be the best solution .

Are you saying that #10 hooked to the RV shore cord would be doable?

Hi,

It would really help to not have as many extension cords, as each connection can have a 1/2 - 1 volt drop across the receptacle and plug.

Do they have an electric dryer? If it is 4 wire, you can buy a 4 wire plug at Home Depot, a plastic junction box, blank cover, some wire nuts, and 50' or so of extension cord (might be less expensive to buy a 50' roll of #10 romex) then connect a 30 amp RV power receptacle at the very end.

On the dryer cord, you want to use the green ground, white neutral wire to the white wire on the extension cord, and one of the two red or black wires (but only 1 as you do not need 220 volts). Tape off the red wire, if you will be using the black one. Put all these connections in a plastic box with the blank cover and use the very large blue wire nuts to make these #10 wire connections.

At the end of the extension cord, use the 30 amp RV receptacle. You will notice that there is a LOT more brass in the 30 amp plug and receptacle than a typical home 15 amp receptacle. This leads to less voltage loss, and much better connection, less likely to overheat.

If the dryer only is 3 wire, then it would not be safe to connect your RV to this type of receptacle, as there is no dedicated neutral wire.

What I did once. Plug into the pits at Bowling Green Race track. They had some #2 wire overhead connected to #10 wire that goes down the power pole to a pair of 120 volt home size 15 amp receptacles - no fuses though. I plugged in a 50' long #14 extension cord across the parking lot, to a #12 25' cord with another 30' #10 cord to my transformer that boosted 100 volts to 112. Then plugged my 30' motorhome cord into that transformer. So about 145' total including the cords to the transformer.

I also needed to monitor the voltage, as it did drop, even with the booster plugged in. At 105 volts, I would recommend shutting off the A/C unit. Over 105, it will be fine.

WHen I lived on a farm, I was about 300' from the main house, on a power line to the pump building. It had a 30 amp circuit breaker at the house feeding $8 wires down to the pump building. I plugged in there, and would have 120 volts. IF I ran my microwave, the indicated voltage dropped about 12 volts. Running the A/C resulted in a 15 volt drop, so I predicted that I had about 1 volt drop per amp being used. By using the transformer, I got back to 132 volts (way to high to plug in the refrigerator to that voltage) and could run the A/C and still read about 118 volts with it on. I did not worry about the TV or other appliances having 132 volts, only heaters and the refrigerator.

So getting a Hughes Autoformer or other booster transformer will solve your problem, and let you use the 120 volt 15 amp receptacle on the side of the house. (yes it is only rated at 15 amps even if connected to a 20 amp breaker). It will also help out if you are using the dryer receptacle adapter, and still had low voltage.

If you find that you are plugging into the house outside receptacle, and when you turn on the A/C trip the circuit breaker only to find out that 1/2 the house or the bedroom receptacles are on the same circuit, you can normally safely plug in the laundry room - it has had 2 each 20 amp circuits to it if the home was built after 1965, per NEC codes.

Good luck,

Fred.