50 amp 120v or 240v

[Spk64]

Maybe this thread should be purged from the system. Too much information that is just not right or relevant.

[FlyingDiver]

Originally Posted by Mr_D

My 240 volt dryer takes 30 amps when on. Add in the washer, electric floor heat, three 15Kw heat pumps, both electric elements on the AquaHot, the household refer, the induction cooktop, the Advantium micro/convection oven and I can easily attempt to draw over 100 amps.
I'm retired, I don't do phase angles or power factors anymore!

Since it's clear you have no idea what you're talking about, maybe you should stop posting?

Yes, you might be drawing near 100amps total, but the current on the neutral conductor will always be less than 50 amps. If you're pulling 50amps on each hot lead, the neutral will be at zero.

[FlyingDiver]

Originally Posted by lonfu

the thing is that most folks don't realize that each line L1 and L2 need to have a seperate breaker of 25 amps. If L1 trips then L2 should trip also. If it doesn't then you have a live circuit at the load. Because one line is out off phase, you get double the power at the load(a dryer as example). L1 provides 25 amps, L2 provides 25 amps out of phase, for a total of 50 amps. If the breakers were 50 amps then they wouldn't blow until they hit 100 amps if over loaded. Look at the circuit configuration. parallel or series..... got to think "2 phase" double the amps. I hesitate to use the term"2 phase" because it is not called that.

Please stop posting this totally incorrect information. Each breaker on a 50 amp service is 50 amps. Both at the pedestal and at the input to the breaker panel in the RV. NOT 25 amps.

[aether_one]

Originally Posted by Jim18655

This is wrong! Each half of the breaker is capable of 50 amps of current. It is NOT measuring 50 amps total for the circuit.

Ummmmmm...... Yes it is.

The ganged breakers each control one "line" of a 240 VAC circuit. The 2 lines are 180 degrees out of phase as has been explained multiple times in this thread and on this forum. In a strictly 240 VAC circuit the current will be the same on both lines and the maximum is 50 amps. If you want to look at it instantaneously: as current leaves one breaker to the load it is coming from the load to the other breaker.

However, when you use the neutral to "split" the 240 VAC into two 120 VAC circuits you could have different currents on the two lines, but neither line can exceed 50 amps. If you have unbalanced loads, say 20 amps on line 1 and 30 amps on line 2, the neutral will carry the difference; but in no case will the neutral ever carry more than 50 amps.

Many people think of this system as two 50 amp circuits for a total of 100 amps, but that is at 120 VAC which is the same power as one 50 amp, 240 VAC circuit.

[Jim18655]

The poster I replied to implied that each half of the breaker was 1/2 of the total rating of the breaker so that you could only draw 25 amps per leg. It is a circuit capable of 50 amps @ 240 volts or 50 amps on each line at 120v with the neutral carrying the imbalance of the current back to the panel. This arrangement is actually more correct in the way the circuit is applied since the feed supplies a panel with several 120v circuits connected to individual breakers
Your point that each leg could carry 20 and 30 amps unfortunately totals 50 amps. If we go one step further and have each carry 30 or 40 amps then the current exceeds the poster's assertion that the current on one line cannot exceed 1/2 of the breaker rating. The breaker will limit the current to 50 amps on one line even if the other is at 0amps.

[tmw188]

To the OP give any electrician your 50a RV plug and the diagram in post #5 just for kicks and all will be ok. The plug itself should tell the story. Too much electrical theory on this thread lately. He will wire it and all will work like it should.