Newbie 50/30 amp adaptor question

[1ViciousGSX]

I have a 2005 3380RL with the 50 amp shoreline connector and cord. I'm going to be camping next week and will be using a 6000surge/5000continuous watt generator to power the basics (i.e. heater/ac, lights, tv, etc). I have the 4 prong twist connector at the trailer and the cord has the big 4 prong 50amp male connector to hook up to the power meter/box. The generator has both the 3 prong twist lock 120v 30 amp and the 4 prong twist lock 120/240v 30 amp outlets. Can I just get a twist lock 4 prong adapter that will allow me to use my current power cord's big 4 prong male end? Also, even though they claim the outlet is 120/240v, am I to understand that the Montana will only use it as a 120v in?

[dmaxmountaineer]

I'm relivly new to the camping world but on my generator i had to buy an adaptor to get a 30 amp twist lock that my honda generator has. When i bought the camper i got a "dogbone" adapter that brings it down from 50amps to 30amps (which most generators are) and also one that brings it down to a 15 amp standard outlet, but only to be used for lights and light power usage. My generator also has a 120/240 connection but has a switch to give you either, or both. My twist lock outlet is on the 120 side, so i figured thats what i need to use. I have the 4 prong twist lock on the 240 side, but i was told i only need the 120v 3 prong twist. Hopefully this helped.

[Art-n-Marge]

Using your 50 amp cord to connect to the generator's 50 amp plug is your best bet since your 6000/5000 watt generator provides all you ever need for your Monty. But it depends how much you are willing to spend. Any cord or adapter that involves the 4 prong twist "Marine" connector can get pricey but they are out there. Regarding 120/240v, I thought the RV would convert whatever voltage comes in to whatever power source you connect to, but I'm not sure. (see dmxmountain's comments above).

Coincidently, there have been recent discussions by forum members about the need for something called "bonding" (different from grounding). I don't know how critical this is because I haven't checked this out but has to do with the neutral and ground being connected to meet electrical codes at ONE point and ONLY one point in an electrical system. Hopefully, someone may come along and describe if there is an issue. In summary, when you connect to shore power, the CG does the "bonding" so you don't have to worry about it. If you had the generator installed into your rig by a professional, I believe they will bond the generator appropriately, and again no worries. The biggest issues are "portable" generators, because unless there is specific documentation that the generator is bonded, then it may not be. Apparently this can be an issue for making sure circuit breakers or GFCIs work correctly.

I hope an electrical expert in the forum comes along to confirm or describe if this is a concern.

[1ViciousGSX]

Oddly enough, my main issue is that the generator has two normal 120v 20 amp receptacles, one 120v 30 amp 3 prong twist lock receptacle and one 120/240v 20amp (x 2) 4 prong twist lock receptacle. There is no standard 50 amp 4 prong receptacle like we see in the camp sites.

[NCFischers]

There won't be a 50 amp 4 prong receptacle because your generator will not output 50 amps. The generator has receptacles to correspond with it's output. Use a 4 wire cord and plug into the 120/240 20 amp receptacle. That is your available power.

[Tom S.]

To add to what Jim said, the 50 amp power you are used to plugging into at camp grounds actually supplies two 120 volt lines, each rated at 50 amps (assuming the campground is wired right - but that's another story). Your generator is capable of providing two 120 volt lines at 20 amps each. Don't get too uptight about the 30 amp difference. The standard 50 amp is designed so you can literally run everything in your unit simultaneously, which rarely happens. As you stated, use the generator to power the 'basics' and you'll be fine.

People often get confused by the term 240 volts. In reality it is two 120 volt lines. They are not connected together to form one 240 volt line, they are run seperately, but because there are two of them, they are referred to as 240 volts. In trailers, as well as stick houses, each 120 volt side of a 240 line supplies one side of the pannel box.

Now for the safety aspect! If you can't find a ready made adapter, have someone experienced in electricity make one for you. Any RV place should be able to do that. Also make sure you place the generator where it is adequately ventilated and won't leak CO2 into the trailer.

[NCFischers]

I want to second what Tom said. Have someone knowledgable make an adaptor for you. Guessing can cause a fire or worse.

[dmaxmountaineer]

I wouldn't trust anyone with an adapter. I think i paid maybe 15 bucks on ebay to go from the 50 amp plug to a 30 amp twist lock that fits my generator. I learned alot about generators with this 5th wheel.

[noneck]

Couple additional points;

Your generator will give you the most energy by using the 240 4 wire each 120 leg at 20 amps

Yes, you could use 30 amp twist lock but that will share the two trailer feeds with limit of total 30 amps from generator output single source

[1ViciousGSX]

OK, here's what I did. I picked up an L14/30A 4-prong twist lock male plug. some 30 amp 4-wire cord, 4-prong 50 amp receptacle & box and built the adapter cable myself. It was really easy as everything was color coded. This gave me the two 120 legs to feed the generator into the 3380RL.

As a precaution I also bought a $5 multi-meter to test the generator output prior to plugging in as I had several people tell me they can be mis-leading or wired incorrectly for their output.

Ran the a/c when needed, the microwave and lighting as needed. No problems what so ever. The microwave tripped one of the 20 amp breakers on the generator once while running the a/c at the same time. I kept the water heater (on only when needed) and refrigerator on gas to lighten the load. Also ran the furnace at times, but since it's a 12v system it didn't really have an effect on the generator.

[Art-n-Marge]

The water heater runs on 12v, so it gets its power needs from the converter when you are running your generator. If you run the refrigerator on propane, then it only needs 12v for the control board and should save even more on power demand. You should be able to run the A/C and the MW at the same time, then. I would have thought that using the 50 amp output for your rig should have easily supported this, unless too many things were running at the same time. Did you have two A/Cs running?

Good job on the wiring and generator. I am jealous.

[1ViciousGSX]

quote:Originally posted by Art-n-Marge

The water heater runs on 12v, so it gets its power needs from the converter when you are running your generator. If you run the refrigerator on propane, then it only needs 12v for the control board and should save even more on power demand. You should be able to run the A/C and the MW at the same time, then. I would have thought that using the 50 amp output for your rig should have easily supported this, unless too many things were running at the same time. Did you have two A/Cs running?

Good job on the wiring and generator. I am jealous.

I ran the water heater on propane vs electricity to save the current for other things. The hot water heater does have the electric heater element also.

I only have one 15000btu a/c unit.

I may have had the a/c kick on in the middle of the microwave usage, but I'm not sure as I was outside when it happened.

The generator only had 41.6 amp continuous output. 5000 watts divided by 120 volts.

The adapter was easy, 4 wires at each end (receptacle and plug). Just match the color of each wire to the color/markings on the plug and receptacle.

[farmboy]

Art, I belive the water heater is 120vac not 12vdc.

[NCFischers]

The water heater is 120 volts. It would never heat enough water on 12 volts.

[ols1932]

I've never had a water heater that ran on 12 vdc. You'd still be waiting for hot water.

Orv

[NCFischers]

Then it would be a barely tepid water heater.

[Tom S.]

I believe Art was referring to when the water heater is switched to propane, it does run on 12v DC. Don't forget that even though it's running on gas, it still needs electricity to open the gas valve and ignite the gas.

[Art-n-Marge]

Oops, yes.... 12v + propane not 110v. Sorry for not being clear enough. Only 12v is needed for control boards and the propane can be use for the major water heater and fridge functions.

In spring, summer, fall months I interchangeably use propane for the water heater and refrigerator (just to make sure it works for when I need it) that way only the A/C becomes the big power draw. But I know plenty of folks on gennys who run their water heaters and refrigerators on propane. In the winter months I use 110v for these devices because I reserve the propane for the furnace and don't use the A/C.

Even with 41 amps I would think that it should support an A/C and the MW. But maybe not BOTH of them starting up at the same time. I use my rig at only 30 amp shore power all the time, but I am not a fulltimer so I don't pay too much attention. I believe we have had the A/C running, with the fridge when using the MW and maybe the Television and have never had a kick off. Did you also have LCD TV(s) running or have other AC demanding devices running? Did the genny kick out only the one time? Have you looked into "bonding" and how it might affect you? A 5000 watt genny should be plenty for your rig without the 2nd AC.

I agree that your cable is pretty solid. Even I have built them and had no problems but I am comfortable with that kind of task.

I hope you keep us posted on your standalone genny use with your rig. It helps keep the eyes and ears open to RV life and what to do about "gotchas".

[1ViciousGSX]

quote:Originally posted by Art-n-Marge

Oops, yes.... 12v + propane not 110v. Sorry for not being clear enough. Only 12v is needed for control boards and the propane can be use for the major water heater and fridge functions.

In spring, summer, fall months I interchangeably use propane for the water heater and refrigerator (just to make sure it works for when I need it) that way only the A/C becomes the big power draw. But I know plenty of folks on gennys who run their water heaters and refrigerators on propane. In the winter months I use 110v for these devices because I reserve the propane for the furnace and don't use the A/C.

Even with 41 amps I would think that it should support an A/C and the MW. But maybe not BOTH of them starting up at the same time. I use my rig at only 30 amp shore power all the time, but I am not a fulltimer so I don't pay too much attention. I believe we have had the A/C running, with the fridge when using the MW and maybe the Television and have never had a kick off. Did you also have LCD TV(s) running or have other AC demanding devices running? Did the genny kick out only the one time? Have you looked into "bonding" and how it might affect you? A 5000 watt genny should be plenty for your rig without the 2nd AC.

I agree that your cable is pretty solid. Even I have built them and had no problems but I am comfortable with that kind of task.

I hope you keep us posted on your standalone genny use with your rig. It helps keep the eyes and ears open to RV life and what to do about "gotchas".

It was a borrowed generator. It only kicked out one of the two 20 amp breakers that one time, so I would guess it was a surge from something kicking on. Otherwise it did perfect.

[KathyandDave]

A question for fulltimers, does your dryer run on 240V or 120V?