Question How many amps does your DP PULL

[redbaron]

Explain the 80 amps. The circuit is rated at 50 amps. The total available amperage to the panel is 50 amps whether it is line one or two. If you exceed the 50 amps the main should trip.

The circuit is rated 50 amps at 240v, which is the same thing as 100amps at 120v. Line 1 & Line 2 are each 120v.

Each breaker can supply 120v @ 50amps. When used as 120v appliances, you get 100amps at 120v, or 12,000 watts of power.

That is why a 12.5Kw generator is required to power the RV the same as when connected to shore.

If you are using a 30amp plug, then you only have 3,600 watts of power available.

A single 50 amp, 120v Line will be 6000 watts of power.

 

[redbaron]

Breakers rated at 80% duty cycle! Notice the two 50 amp breakers are tied together? That keeps a 220vac load from having a hot wire if you trip it.

So 50amps per leg 100 amps Total. Times 80(80%) equals 80 amps. If neither leg exceeds the breakers limit!

That is why you should strive to balance the legs.

This is why campgrounds so often have bad breakers. Many, like myself, will commonly use 90-95% of the load. This wears out the breakers very quickly.

Plus all the turning on/off as we break camp and setup camp.

 

[MemoriesByTheMile]

For a 50A hookup at home base, we have a separate disconnect switch at the outlet so the breaker isn’t being flipped on and off regularly. The breaker isn’t adjacent to the outlet.
I figure the only reason campgrounds don’t use disconnect switches is they either don’t know better or they are being “penny wise and pound foolish” and like replacing breakers on a regular basis.

 

[newmarokie]

Let's add another twist. Yes, campgrounds have a 50 amp double pole breaker. 50 times 240 = 12,000 watts of power. Like Kevin says and I believe the NEC says, circuits should be sized to run at 80% of rating. My 19 Dutch Star has an 8k Onan generator. It has a 35 amp double pole breaker. But it is pure 120v. If you measure across the lines it measures zero. Each line to neutral measures 120v. The legs can be tied together to make 70 amps of 120v but not split to make 35 amps of 240. I am still not completely certain how this all fits together and works(flawlessly I might add). I know the genny has the two lines and two neutrals going to the transfer switch that bond together there. I have not determined if the main line going to the panel has a oversized neutral to help compensate for the 240 volt pedestal power being out of balance. I know with both ACs going and the inverter/charger going full tilt, the system is definitely out of balance. About thirty amps on the leg with one AC and the inverter, about fourteen on the other. Maybe that amount of imbalance is with in the limits of the neutral? Maybe the panel is balanced well enough that you can't hardly overload the neutral?

 

[redbaron]

Let's add another twist. Yes, campgrounds have a 50 amp double pole breaker. 50 times 240 = 12,000 watts of power. Like Kevin says and I believe the NEC says, circuits should be sized to run at 80% of rating. My 19 Dutch Star has an 8k Onan generator. It has a 35 amp double pole breaker. But it is pure 120v. If you measure across the lines it measures zero. Each line to neutral measures 120v. The legs can be tied together to make 70 amps of 120v but not split to make 35 amps of 240. I am still not completely certain how this all fits together and works(flawlessly I might add). I know the genny has the two lines and two neutrals going to the transfer switch that bond together there. I have not determined if the main line going to the panel has a oversized neutral to help compensate for the 240 volt pedestal power being out of balance. I know with both ACs going and the inverter/charger going full tilt, the system is definitely out of balance. About thirty amps on the leg with one AC and the inverter, about fourteen on the other. Maybe that amount of imbalance is with in the limits of the neutral? Maybe the panel is balanced well enough that you can't hardly overload the neutral?

The 10kw and 12.5kw are 240v.
-edit: I don't know why I am getting conflicting information on the 8kw..some are made 240v, some are made 120v single phase, with separate neutrals and cannot be 240v---its an odd setup.

https://www.cummins.com/generators/onan-qd-8000

 

[AbdRahim]

 

[newmarokie]

Baron, I agree with you. Mine is a Q8000. Onan plainly states 120v. It is making an upgrade to solar, and 48v batteries a real challenge. I have been hinted to that it could probably re-tapped to produce 240v, but nothing definitive.

 

[Kevin D Pem]

Balancing has to do with load distribution between L1 and L2. This has nothing to do with the Common.
The common is the same size as the 110 line or 220 lines. This is due to sine wave characteristics.

220 vs 110 generators are simply wound for the desired voltage. This has nothing to do with watts. And everything to do with requested configuration. As an example, a 1000 watt inverter generator sold in many other countries will be 220v. Same generator, different configuration and RPM. You will find a different model number that depicts the voltage of the unit.

Yes! On the generator side of the transfer switch, you can tie both lines from the house to make All house wiring work even though you are not connected to 220. Remember all circuits are designed and protected based on wire size, so no harm no foul.

 

[newmarokie]

Kevin, I understand all of that. That is why I mentioned how out of balance the system is when the inverter is running. The two ACs and the inverter are the three biggest electricity hogs on our coach that we run consistently. We use ac I on the Oasis, but it doesn't hi the load often. The two lines do not tie together, the two neutrals do. the lines go to the opposite side of the transfer switch from the two 120v legs of the pedestal power. There is nothing in the coach that runs on 240v, so from a line perspective, the coach doesn't care. It just seems to me, that if you are using two separate 120v legs off of a 240v circuit you could possibly need two neutrals or a larger neutral to cover for imbalance. What is the coach doing when the two separate in phase 120v legs are powering the coach as opposed to two 120v split phase legs are powering the coach? This last sentence is the crux of my quandry.

 

[Kevin D Pem]

Still comes down to 35 amps on 50amp circuit. Or put another way 35amp protection on 50 amp circuit.