FiverBob wrote: One thing not mentioned on the 50a service: If you put a meter between the two hot legs, you will measure 240v. Put the meter from neutral to either hot leg and you measure 120v. The panel is split in two sections allowing the load to be distributed between the two 120v legs but the total current flowing still cannot exceed 50a.
Bob
Confusing post. The current cannot exceed 50A in each hot leg or 100A total.
Sorry Bob, but this can be confusing - - I know the feeling. A 50a service is exactly that - - 50a - - just like a 100a service in your home allows you to draw a maximum of 100a before the breaker pops (hopefully if all is working correctly). Our 50a service in the RV is NOT really 100a like we would like to think - - it is 50a, period - - no more. It is a total of 240v at 50a. A 30a service is 30a - - period. Jumping from a 30a service to a 50a does not give you an extra 70a. The 50a gives you an extra 20a more than the 30 and that makes a huge difference in being able to run a lot more things without popping breakers. One thing that is so neat is the ability to break the box into two sections so the projected load can be distributed. Hence, you will note the front Ac is on one side of the panel, the BR Ac on the other side. Typically the microwave is on the BR AC unit side of the panel allowing the MW to run while the living area Ac is running.
Yeh, I know - - confusing. LOL
Bob
2003 Dodge 3500 HO dually 6 speed Laramie, Jordan Controller, RDS aux tank/tool box, Bremen boards, RamAirIII, Jacobs EBrake, Air Safe 25K hitch
Carriage 36' Triple slide Fiver, Onan Gen, Sat, Prosine Inv., MORryd IS and pinbox
skylos wrote: What if you look at it as available watts? (instantaneous power available)
a 30 amp single leg has 30A*120V = 3600 watts available.
A 50 amp double leg has 50A*120V*2 = 12000 watts available.
which makes the 50 amp connection capable of providing 3.3 times the power of the 30 amp.
So when you plug in that big chunk 4 conductor plug into the NEMA 14-50R you can cackle, "MUAHAHAHA! TWELVE THOUSAND WATTS!"
Hey hey, a man that understands this stuff - - ain't it fun? How you state the double leg can be confusing to some - - if you state 240v x 50a = 12,000 watts, it might be more understandable. Some will try to get a total of 100 amps out of the statement of "double." Just a thought. Anyhow, 12,000 is a whole bunch more than 3600, that is for sure.
Hey, heading your way again next spring, Big Dave - - love it up there.
Bob
PS - - I just re-read your comments, Skylos, trying to see how you are looking at this thing. You are isolating each side to see what is happening while I am looking at it more like an electrician would look at a service - - a 50a service is so named because the maximum current that can flow at 240v is 50a. I guess if you wanted to look at each circuit individually, that could prompt the thought of 100a, but at 120v. Interesting - - I just had not thought of it that way. In any event, I will sure opt for the 50a when possible. YEH I think the name of the game is Semantics 101.
* This post was
edited 06/22/11 07:48pm by FiverBob *
skylos wrote: What if you look at it as available watts? (instantaneous power available)
a 30 amp single leg has 30A*120V = 3600 watts available.
A 50 amp double leg has 50A*120V*2 = 12000 watts available.
which makes the 50 amp connection capable of providing 3.3 times the power of the 30 amp.
So when you plug in that big chunk 4 conductor plug into the NEMA 14-50R you can cackle, "MUAHAHAHA! TWELVE THOUSAND WATTS!"
Hey hey, a man that understands this stuff - - ain't it fun?
I always thought so.
FiverBob wrote: How you state the double leg can be confusing to some - - if you state 240v x 50a = 12,000 watts, it might be more understandable. Some will try to get a total of 100 amps out of the statement of "double."
But it IS 100 amps of 120 Volt, if you want to slice it that way. Choose any one:
Double the circuits
50A @ 120V + 50A @ 120V
double the current
100A @ 120V
double the voltage
50A @240V
But if you add/multiply them up, its always the same power!
FiverBob wrote:
Hey, heading your way again next spring, Big Dave - - love it up there.
big dave wrote: Bob, 4 of us went after halibut yesterday, kept 8, were out about 4 hrs.
OH STOP IT RIGHT NOW!!!! We all got our limit my last time out and switched over to salmon to finish out the day. Great time. I think the neatest thing is when you can walk a few steps out of your fiver, throw a jig into the river, pull in a salmon for supper and go "home" and eat it. The only bad thing is the scenery you have to endure while fishing - - too many glaciers around you, bears in the river with you fishing, moose wandering the shore - - really is tough to take. NOT. Sooooo, see, I am jealous. Just for that I am going out in the boat tomorrow and catch another tarpon - - they are hitting around here big time. 120 pounder last week end. Hey, enjoy and don't catch them all before I get there.
Iar5: Yes, you can use an adapter to power your 30A FW with a 50A service. Your FW will not know the difference. My FW is 30A and I always use the 50A adapter if that is available at the power pole. The only technical issue with it is you are no longer protected by the power pole breaker (50A) just your trailer main breaker (30A). Not a practical problem in actual use
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We all got our limit my last time out and switched over to salmon to finish out the day. Great time. I think the neatest thing is when you can walk a few steps out of your fiver, throw a jig into the river, pull in a salmon for supper and go "home" and eat it. The only bad thing is the scenery you have to endure while fishing - - too many glaciers around you, bears in the river with you fishing, moose wandering the shore - - really is tough to take. NOT. Sooooo, see, I am jealous. Just for that I am going out in the boat tomorrow and catch another tarpon - - they are hitting around here big time. 120 pounder last week end. Hey, enjoy and don't catch them all before I get there. 
