Pulling more than 50 amps ?

Not sure where you are coming up with amperage for shore power cord. Cord amperage is covered by NEC article 400. Ampacity is Art 400.5(A). #6 is rated for only 45 amps. #8 is rated for 35 amps. NEC allows you to go up to the next standard breaker which is 50 amp.

hypoxia wrote:
On an RV that has zero 240 volt appliances is there a reason to have the tied 50 amp breaker instead of two separate 50 amp breakers?

Yes but it is highly technical But I try again:

Assume that between transformer and you is a 2 volt drop each way at 50 amps (At 100 amps that's 4 volts each way)
Now that means 120 volts at the transformer or no-load = 112 full load OUCH that's some serious voltage drop.

Now let's split it to two 50 amp legs. Right away the voltage drop one way goes from 4 to 2.. but wait there's more

IF just one leg is in use we have 2 volts out and 2 back for 116 volts at the RV
But if both legs are in use we have 2 volts out and 2 back for 118 volts at the RV.. Why? Well the 4 volts round trip comes off the 240 volts and that's divided so ..

It means way smaller cables are needed for the same voltage drop

Makes 100% sense

I hope I've explained it well enough but if not.. Pleas ask about the confusing parts and I'll try to clarify.

Alas... THis is what is called "College level" stuff. or intutitive depending on what you studied in college :)

If the run is short I believe #8 is fine for a 50 amp connection.
I would not be surprised to see #8 feed the 50 amp connector in the pedestal.

MEXICOWANDERER wrote:
No 6 CU is absurd for 50 amp service.

Not sure what you're getting at here. I just had a #6 Copper 50a service installed at my home.

Point is......

A double standard for RVs. Look what is NEC CODE for an electric stove.

No 6 CU is absurd for 50 amp service.

pianotuna wrote:
Hell's bells why not use gold? *grin*

Silver is lower cost and conducts better than gold or copper.
Go ahead and have it gold plated for corrosion resistance ;)

wapiticountry wrote:

MEXICOWANDERER wrote:
If at home
Go outside
Look at the gauge of cable servicing your drop. 100 or 200 amps AL.

50 Amos demands 6AWG CU. conductor.
It is a mere distance between your transformer and your service drop. Now look at how an RV Park is wired (shudder)

50 amp service does not demand copper conductors. Modern parks are most often wired with 4/0 4/0 4/0 direct burial aluminum with a #2 aluminum ground in a loop feed. (Note that the neutral is not allowed to be undersized in RV park applications). That is up to current code and works just fine.

Mex was point out that #6 copper is the minimum size. Of course, Aluminum may be used--but requires larger than #6

Hell's bells why not use gold? *grin*

Folks can't figure out the simple Single Split Phase system so 3 phase should make their minds explode..

Single Phase VS 3 Phase wiring

In practical terms on a 50 amp pedestal you can draw 40 amps st 240 volts continually. We have an electric car and we sometimes do that.

Real world experience. Visiting a friend with a Newell with three AC’s, all running as well as a bunch of other things. Our Electric vehicle hooked up to his pedastal via a Y connector off the box pulling16 amps at 240. No problem.

I sure wish RVs had 3-phase power so we could have 150 amps ;)