Generator 120v or 240v

[Mr_D]

Originally Posted by LJowdy

Shore power 50 amp service isn't 240 volt but rather (2) separate 120 volt circuits theoretically (1) 30 amp line and (1) 20 amp line .

50 amp service is 2-120 volt lines, L1 and L2. Each with a 50 amp breaker so you can potentially draw 100 amps @ 120 volts.

[Mr_D]

Originally Posted by Shawn6596

50 amp shore power is 50 amps @ 240v. Yes the RV only uses 120v appliances, but the wiring and service is 240v. Here is a video that explains it.
Your statement "(2) separate 120 volt circuits" is exactly how 240v is achieved. 120v from the A phase, and 120v from the B phase create 240v.

Not always!! Some high end coaches use 240 for a cooktop or dryer. Mine has a 240 volt dryer.

[MisterT]

yes, that's why it's 240v coming thru your Shore Cord, but your breaker panel setup determines whether any of your breakers are designed to use the 240v power, like for a dryer, or whether everything is 'split' onto either side of the panel for only 120v power, which is the typical RV setup.

yes, 50amp RV service can easily be suggested as two different 120v 50amp lines, and it's easy to swallow it that way when describing it, but it's actually still 240v service from a 'full power' standpoint. I also sometimes describe it to those who are new as two separate 50amp hot lines of 120v service, but that's just to 'ease' the conversation and understanding of why you have a double-pole breaker, and not a single breaker, like on a 30amp outlet.

it's when someone describes RV 50amp Service as the same as a 30amp breaker and a 20amp breaker combined, I cringe. It may seem that way when you just 'say' 50amp service, but when you look at the double-pole breaker, you have to assume something much different.

[twinboat]

Originally Posted by LJowdy

Shore power 50 amp service isn't 240 volt but rather (2) separate 120 volt circuits theoretically (1) 30 amp line and (1) 20 amp line .

That's not true. 50 amp shore power is 50 amp 240 volt service. The RV uses it as 2, 50 amp, 120 volt lines.

[Shawn6596]

thank you folks. those were the answers I was looking for. just wanted to be sure there wasn't anything RV specific I should be concerned with. I have traced all the wires from the panel through the transfer switch and back to the generator. everything appears to be wired in a very standard 240v configuration. I only asked to be sure there weren't any traps I should be looking for. again thanks guys

[MisterT]

congrats, and if you follow thru with your plan, let us know how it works out.... others may be interested in the very same idea : )

[twinboat]

If you set up your 8000 watt generator for 240 volts, you will only have 33 amps per leg.

One of your legs will probable need more then that to run one AC and your water heater. At 50 amps, that will work, at 33 amps, it will trip a breaker.

With the generator outputs combined as 120 volts, as it is now, you have 66 amps shared between both legs. You can pull more then 33 amps on the leg that handles the high amp draw items.

[aether_one]

Originally Posted by LJowdy

Shore power 50 amp service isn't 240 volt but rather (2) separate 120 volt circuits theoretically (1) 30 amp line and (1) 20 amp line .

Absolutely wrong!

But I see i was beat to it.......Several times.


Hard to believe with all the 120 VAC/240 VAC 30 Amp, 50 Amp, 100 Amp threads on this forum there are still people who propagate incorrect information. It's OK to be misinformed: just don't spread your misinformation.

[aether_one]

Originally Posted by twinboat

If you set up your 8000 watt generator for 240 volts, you will only have 33 amps per leg.

One of your legs will probable need more then that to run one AC and your water heater. At 50 amps, that will work, at 33 amps, it will trip a breaker.

With the generator outputs combined as 120 volts, as it is now, you have 66 amps shared between both legs. You can pull more then 33 amps on the leg that handles the high amp draw items.

This answers my would-be question of why it was wired for 120 VAC in the first place.

[MisterT]

Originally Posted by Mr_D

50 amp service is 2-120 volt lines, L1 and L2. Each with a 50 amp breaker so you can potentially draw 100 amps @ 120 volts.

hey Mr D! I just thought of something... send us a picture of your breaker panel... getting eyeballs on your 240v double-pole breaker for your dryer will be a help in all of us understanding the 240v vs 120v disagreement.

My understanding is this: just like your home's breaker panel(go look and see), you have two 'sides' of breakers, just like your RV, though since your RV's box might be set up horizontally, you might not think it looks the same, but it really is.
Electricians have to manually decide how the box is 'separated' by the number of breakers needed, and must install them for an 'equal' share of the power. So, if one side has 100amps of breakers, in total, the other side will have a similar or same number of amps. RV Factories do the same, only on a smaller scale, 50amps, or so, on each 'side'. All 'single' breakers will be 120v since they only use one 'side' of the incoming power, or one 'leg' of 240v, which is 120v.

Now, whenever you see a 'Double-pole' breaker(such as 2 30amp breakers with a shared 'handle'), you are actually seeing a true 240v circuit, which will go to something such as a dryer, which requires higher power for all of the heat that it generates. Ultimately, this is like 60amps totals to the dryer, not just 30, since it's 'two' separate 30amp 120v lines, but going to a single source, with a shared neutral.
Most of our coaches do not have a double-pole breaker within our panel because we don't have any 240v appliances... though, Mr D does!

If 50amp RV service wasn't really 240v service, just like your home, then Mr D could not use his dryer...that would make for a sad wife! : /

[Gary RVRoamer]

Shore power 50 amp service isn't 240 volt but rather (2) separate 120 volt circuits theoretically (1) 30 amp line and (1) 20 amp line .

Even without the inevitable 120 vs 240 arguments, that's just plain wrong! At the very least it would be 2 x 120v/50A circuits. Standard RV 50A delivers up to 12,000 watts of power.

[bruceisla]

Originally Posted by twinboat

If you set up your 8000 watt generator for 240 volts, you will only have 33 amps per leg.

One of your legs will probable need more then that to run one AC and your water heater. At 50 amps, that will work, at 33 amps, it will trip a breaker.

With the generator outputs combined as 120 volts, as it is now, you have 66 amps shared between both legs. You can pull more then 33 amps on the leg that handles the high amp draw items.

35 amp genset breaker(s)?

[Shawn6596]

Originally Posted by twinboat

If you set up your 8000 watt generator for 240 volts, you will only have 33 amps per leg.

One of your legs will probably need more than that to run one AC and your water heater. At 50 amps, that will work, at 33 amps, it will trip a breaker.

With the generator outputs combined as 120 volts, as it is now, you have 66 amps shared between both legs. You can pull more than 33 amps on the leg that handles the high amp draw items.

You have a very fair point, but the water heater is gas/electric. I have no intention of using it on electric portion of the water heater unless I am on shore power. That being said I may investigate changing it over to 240 if I go that route. also the breakers on the generator are 35 amps.

[twinboat]

[QUOTE=MisterT;4197531]hey Mr D!



. Ultimately, this is like 60amps totals to the dryer, not just 30, since it's 'two' separate 30amp 120v lines, but going to a single source, with a shared neutral.
Most of our coaches do not have a double-pole breaker within our panel because we don't have any 240v appliances... though, Mr D does!
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It is a true 240 volt circuit, but it doesn't share a neutral, it doesn't us a neutral at all. The heater coils are 240 volt.

If you double the voltage, the amp draw is halved. That makes it a 30 amp, 240 volt circuit.

The dryer does use some 120 volts for the motor and control but that's the only reason the neutral is there.