How long can you go on a 50 amp extension cord?

If the silver plug can handle 15-20 amps I’m pretty sure 3 of the larger ones can handle the load the OP will put on them.

In my estimation the weakest link will be the connectors. You would be better off running a 100 foot straight cord rather than several cords plugged together. There will be some voltage loss with each connection. If you do run more than one cord make sure the connectors have been inspected and wires tightened.

By store bought you mean pre-made wire sections..My experience says if your running near 50amp the plugs will burn up first

valhalla360 wrote:

time2roll wrote:
If you only see 220 at the outlet with no load in a single family home it is time to call the power company.

Power company only has to worry about the connection up to the meter and they automatically get a 5% deduction and are still in spec. Plus if it's hot out and the whole community is running air/con full blast, they will shrug at your complaint that it's down to 110v entering the house. They aren't going to rebuild the power grid for an issue that happens 2-3 times per year.

I would still call and insist my connection to be checked in person if the main feed was consistently 220 volts or less.

I carry a 40 foot 50 amp cord as my main connection. I also carry 3 - 15 foot extension cords as I am sometimes a good distance from the power source. That's 85 feet with multiple junctions and I have run for more than a month with that setup. A direct 100 foot cable should perform even better. The cable uses 3 #6 and a #8 ground wire which I believe is pretty standard.

I’m currently running one AC on a 100’ long #10 cord plugged into a 15A outlet. I routinely run 2 15K ACs on a 30A outlet...what the OP is wanting to do using a 50A cord. Each AC (15A) SHOULD be on its own leg of the 240V/50A ...even if both AC are on the same leg (easy enough to correct) it’s not going to be a problem. Another thing that only in the RV world do we worry about ...16A on a 50A wire.

supercub,

If I'm reading your post correctly, you only NEED to add 30' to what is already there to make the 100'. So the posts above about the weight of a 100' cable are not relevant. Your current cable is 30', so you already know what a 30' cable weighs. :-)

As far as being doable, in general, I would say yes. It DOES depend on the voltage at the house. If it's in the normal acceptable range, there shouldn't be any problem. However, if it's low (either due to power utility supply, poor or old wiring in the house or localized "brown-outs"), then you'll have to be watchful of the voltage.

You can purchase plug-in voltmeters you can plug into your RV to monitor the voltage when both ACs are needed. Get two and plug each one into an outlet on each leg of the supply.

Someone brought up the point that both ACs might be on the same leg. If that's the case, I would STRONGLY recommend that one of them be moved to the opposite leg. That way, when BOTH ACs are running, the current through the neutral wire will basically be ZERO for the ACs. So you won't have any cable heating with a heavy current down the neutral. If both ACs are on the same leg, the neutral current will be the COMBINED current of the two ACs. If they're on opposite legs, the neutral current will be the DIFFERENCE between the two ACs. Assuming the ACs are similar, then that would be about zero.

Perhaps that was too much info? Sorry if it was.

By the way, I've routinely used 70' of cable at my brother's house without any issue. My RV has a 30' cord and I added a 15' and 25' extension cord. Again, if the voltage is proper at the homestead, I don't think you'll have any problem.

Good Luck, and let us know how you make out!

~Rick

Take the two cords you have in hand and measure the voltage. If it looks decent enough than purchase the remainder of needed cord. Measure voltage again. Unless you are using all available power( 100 amps) your going to be ok using #6 flexible cord for your needs. I'd just add to keep your eye on your in RV voltage while using the airs!

Voltage at an outlet can only be accurate if you are reading it while it is under the full load that you plan to use.

time2roll wrote:
If you only see 220 at the outlet with no load in a single family home it is time to call the power company.

Power company only has to worry about the connection up to the meter and they automatically get a 5% deduction and are still in spec. Plus if it's hot out and the whole community is running air/con full blast, they will shrug at your complaint that it's down to 110v entering the house. They aren't going to rebuild the power grid for an issue that happens 2-3 times per year.

Depending on load and internal voltage drop from the power meter to the outlet, you can easily lose a few more volts before considering voltage drop on the 100ft extension cord.

To the OP: You may have perfectly fine voltage and it might not be an issue. My point is to check and keep an eye on the voltage. Don't wait for the smell of a burnt out air/con unit to clue you in that you have a voltage issue.