keigm Report post Posted January 3, 2019 With my questions you can tell I’m a neophyte. I’m trying to learn all I can about my coach. It is a 2014 Mountain Aire. I see on the silver leaf AC is single phase and automatic. Where can I go to learn more about what all this means. What is load shed? Should it be on Automatic all the time?... Anyway, I would appreciate any advice. Thanks. Share this post Link to post Share on other sites
rossboyer Report post Posted January 3, 2019 We need more information about your motorhome. Is it a 30 amp or 50 amp service? If you are unsure, 30 amp has a 3 prong power plug and 50 amp has 4 prong. Share this post Link to post Share on other sites
keigm Report post Posted January 3, 2019 It is a 50 amp all electric coach. 2800 watt inverter 10,000 watt generator. Residential refrigerator. Share this post Link to post Share on other sites
richard5933 Report post Posted January 3, 2019 Single phase is pretty much the standard electric service in residential buildings. The other option would be three phase, something usually found in commercial or industrial settings. Look at Wikipedia for an explanation. Share this post Link to post Share on other sites
jleamont Report post Posted January 3, 2019 Keigm; I would be willing to bet that the modern day coaches are following whats available for campgrounds shore power. If someone introduced something other than what is the normal we that poor end user would find anywhere for the next 20 years that would be able to accommodate them. I struggle to locate campgrounds with 50 amps. A 50 amp coach actually has 220vac coming in on two separate legs (2 -120's) but still single phase. Load shed, the Energy Management System will calculate power in and power out, if out is asking for more it will automatically cut off items deemed less necessary to provide the request. I leave ours set to Automatic all the time. Share this post Link to post Share on other sites
ianbullock Report post Posted January 3, 2019 24 minutes ago, jleamont said: I struggle to locate campgrounds with 50 amps. That's odd. Almost everywhere we stay 50 amp service is available. We mostly stay at private CG's. Share this post Link to post Share on other sites
jleamont Report post Posted January 3, 2019 24 minutes ago, IanBullock said: That's odd. Almost everywhere we stay 50 amp service is available. We mostly stay at private CG's. So do we, in fact I can count on one hand how many State or Federal parks we have been to in 10 years. I have found that if you call around an area you are intending to explore someone will have it, but you have to seek it out. Share this post Link to post Share on other sites
wayne77590 Report post Posted January 3, 2019 I also have not found it to be a problem finding 50 amp service. Keigm, Get a good understanding of RV electrical service. One cannot plug an RV into a standard household 30 amp supply as that provides 220v and will fry things. Here is a good start: 50amp Electrical Service Share this post Link to post Share on other sites
manholt Report post Posted January 3, 2019 Well, campgrounds started with 15 amp service, then RV's came out with 30 amp and later 50 amp, now (past 10 years+) it's a lot of coaches that are set up for 100 amp! Soon there will be that available at campgrounds. Currently, it's mostly private and high end resorts that have it. As it is, I have not had a problem finding 50 amp...but hen maybe it's a PA. thing! Share this post Link to post Share on other sites
richard5933 Report post Posted January 3, 2019 Still lots of smaller campgrounds with only 30-amp hookups, as well as those with only a few 50-amp pedestals. We stopped at a few on our drive from NJ to Wisconsin. Always good to have a plan for making do on 30-amp. Share this post Link to post Share on other sites
ianbullock Report post Posted January 3, 2019 Yeah, we can always make 30 amp work if we have to.. Share this post Link to post Share on other sites
jleamont Report post Posted January 3, 2019 1 hour ago, IanBullock said: Yeah, we can always make 30 amp work if we have to.. YUP, don't like it but have gotten by with it in the past. It gives our EMS system a work out deciding what to shed when I turn the Keurig on Share this post Link to post Share on other sites
jleamont Report post Posted January 3, 2019 2 hours ago, manholt said: maybe it's a PA. thing! You wait until you hit New England wise guy, just locating a campground can be a challenge that you can fit into let alone has 50 amp with W/S . Only the newer ones, the older spots,.,.,. bring your PowerPal, id bet its got a 50 amp plug with a 120 jumper on the back side all connected to the 30 amp plug https://50amppowerpal.com/ Share this post Link to post Share on other sites
rossboyer Report post Posted January 3, 2019 Try rv electric newsletter written by Mike Sokol. Read back issues. You can get to his web site via rv travel web site also. Share this post Link to post Share on other sites
sstgermain Report post Posted January 3, 2019 7 hours ago, jleamont said: Keigm; I would be willing to bet that the modern day coaches are following whats available for campgrounds shore power. If someone introduced something other than what is the normal we that poor end user would find anywhere for the next 20 years that would be able to accommodate them. I struggle to locate campgrounds with 50 amps. A 50 amp coach actually has 220vac coming in on two separate legs (2 -120's) but still single phase. Load shed, the Energy Management System will calculate power in and power out, if out is asking for more it will automatically cut off items deemed less necessary to provide the request. I leave ours set to Automatic all the time. It's 240 vac coming in. Two 120 legs. Share this post Link to post Share on other sites
kaypsmith Report post Posted January 3, 2019 Todays electrics use only single phase or three phase, 240 volts are sometimes mistakenly called two phase but is not a true statement because 240 using two 120 volts are exactly 180 degrees out of phase with each. To be two phase, and was sometimes used in the early 1900's (twentieth century) was 110 volts twice and only 90 degrees out of phase, the motors that use that setup are harmonically imbalanced. Three phase has a third hot leg within the 60 cycles and usually is 190 to over 200 volts depending on which designation the delta is called. Share this post Link to post Share on other sites
wayne77590 Report post Posted January 4, 2019 16 hours ago, sstgermain said: It's 240 vac coming in. Two 120 legs. That's what she said ...Errr... Joe said. 😀 He said, "A 50 amp coach actually has 220vac coming in on two separate legs (2 -120's) but still single phase." Actually each "leg" is 50 amp and capable of 6000 watts each. Overall a 50 amp coach is capable of 12000 watts Totally. However, circuit breakers are not exactly 30 or 50 amp. They have a 20% plus or minus capability. So either service could trip below or above their rated capacity. Always plug into 50 amp if you have a 50 amp service and 50 amp is available. A 30 amp service is only capable of 3600 watts, way below the capacity needed to run a 50 amp RV sufficiently. Those ratings are based on 120v. Yes, I have the EMS also (Electrical Management System) and it works on 30 amp or 20 amp, not 50 amp. On our last trip out there were some campgrounds (all 50 amp service) where I could run all 3 roof AC's and there were some that it would trip the breaker. Temps out side were in the upper 90's. I just automatically started using just to and we were very comfortable. Had we only had 30 amp service available, 1 AC and very little else would be able to run. Share this post Link to post Share on other sites
jleamont Report post Posted January 4, 2019 28 minutes ago, wayne77590 said: Had we only had 30 amp service available, 1 AC and very little else would be able to run. Interesting, we always run both AC unit, since they do not cycle together it has never been an issue. Share this post Link to post Share on other sites
manholt Report post Posted January 4, 2019 I run 2, the front zone & rear zone, on 50 or 30, except when it's over 90 and humid, then I run middle zone...for that, you need 50 amp! You get 45 A on each leg, that's usable! So, when on 30A figure 27 usable! Share this post Link to post Share on other sites
wayne77590 Report post Posted January 4, 2019 I have not been in a situation with the newer to us MH that I had to run on 30A. Share this post Link to post Share on other sites
manholt Report post Posted January 4, 2019 Wayne, like me! It will happen. I suspect, I'll be on a couple of them in Canada, this Summer! Share this post Link to post Share on other sites
richard5933 Report post Posted January 4, 2019 I believe that most roof-top a/c units can run on a 15-amp circuit, with actual draw slightly less than that. Technically it might be possible to run two units on 30 amps, but I'd guess that at some point they'll cycle at the same time and the start-up draw might pop the breaker. Or, more likely, the battery charger or something else which was forgotten will kick in and increase the draw over the 30-amp limit. Obviously I'm talking about those with more manual power management. In our coach each of the a/c units draw 19 amps on startup, and about 15 otherwise when the compressor is running. We can run one on 30 amps, with a little left over for things like lighting, battery charger, and fans. Lucky for us our basement a/c units will turn the coach into a meat locker if we want, so one can usually keep us comfortable enough. We had only 30 amps in Gillette, but there was no problem keeping cool inside. Since our kitchen is all electric, we carry a portable propane single burner stove which we use whenever we're hooked up to 30-amp service. If we use the microwave, the a/c is first switched to ventilate only with the compressor switched off. Share this post Link to post Share on other sites
manholt Report post Posted January 4, 2019 Yep, I remember well, when we only had one AC and no ducts and a small microwave...we had to turn of one to run the other! It beat a tent on the beach! Share this post Link to post Share on other sites
wayne77590 Report post Posted January 5, 2019 Prior to MH's I had a 5er with two AC's. I used to plug into the 120v line in the garage. I could run one roof top AC but if I turned on a vacuum cleaner it would blow the breaker. So any time we wanted to clean it up we would cool it down and then turn it off to vacuum. Share this post Link to post Share on other sites
gordiegaffer Report post Posted January 18, 2019 Remember when you have a 50 amp service it is 50 amp 4 wire two hots one neutral and one ground it is not a 220/240 setup like your dryer or stove which is 50 amp 3 wire two hots and a ground. Share this post Link to post Share on other sites
