Elect sys protection

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Cant Wait

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Joined
Feb 19, 2010
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726
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Jamestown, NY
I've been reading lots of posts on what people are doing i.e. surge protectors, autotransformers, cheater boxes etc. It seems that for every yes there is a no on the use of these items. I know that the surge guard is a MUST. My issue is that where we camp most the hook-up is 30amp. With the AC set-up my unit (2012 Journey 40U) has, zone 1 has 2 AC's running, and zone 2 has the bedroom AC with no other options. With the AC set on zone 1 the draw is 26amps, this leave very little for anything else.  Is there a way to cut-out the 2nd AC on zone 1 setting? From what I've read the cheater boxes that let you hook into both the 30 & 20amp at the pole to get 50amp don't really work in that the GFI 20 amp breaker keeps tripping. Has anyone used the JTB Power Solutions system that does (according to them) combine the 30 & 20 amp without tripping the 20amp GFI all the time for use with 50amp systems?
 
The JTB Power Solutions box isolates one AC from the main breaker panel of the RV and connects it directly to the 20 amp receptacle on the power pedestal. This will work fine as long as the 20 amp receptacle is wired separately from the 30 amp receptacle as it should be if wired correctly. In some campgrounds it may be derived from the 30 amp breaker and then would not work as you would again be exceeding 30 amps with certain combinations of loads. It will resolve the GFCI problem of some of the 20/30 amp to 50 amp combiner adapters.
 
The second a/c in zone one should have its own circuit breaker in the RV's load enter (breaker box). Just turn it off if you don't want it to run.

The JTB Power Solution is to rewire one a/c to use an independent 20A outlet. It's not "plug & play" like the Y adapters or "cheater" boxes, but it does work as long as the park power box has a separately powered 20A outlet. Most do not, in my experience, but Corp of Engineer parks and some state parks may be wired that way (it costs a lot more). Power poles that have 50/30/20 outlets do have separate 20A power source, but you don't need it if 50A is available anyway.

You may also find that some (many?) parks will not allow you to hook up that way. Basically you are paying for 30A electric but using much more, i.e. 30A+20A. Some will charge extra for it, but in my limited experience doing this, most just say NO. Of course, they may not notice it either.

A Surge Guard + power monitor is a very good thing to have, but I don't think I would classify it as a necessity. A lot depends on the quality of the parks you frequent and whether you do any checking yourself before hooking up.
 
Gary RV Roamer said:
A Surge Guard + power monitor is a very good thing to have, but I don't think I would classify it as a necessity.

I don't often disagree with a guy as sharp as Gary, but this is one time I do. The primary reason I recommend a Surge Guard is for the random low voltage at any park. I have stayed in 5 star RV exclusive resorts, and one horse campgrounds in the middle of no where.  You can run into low voltage anywhere. And low voltage is worse in my opinion, than a voltage spike. Low voltage can do it's damage and you will never know until a long ways down the line when your refer,  or A/C suddenly burns up for no good reason. 

My surge guard has disconnected my power several times, when the other rigs around me seemed to be "fine".  But a check of the A/C power gauge showed 100 volts coming into the rig. This causes electrical motors to run hot, lug, and eventually fail.  I do classify the surge guard as a necessity.  Just my two cents, you make your own call. 
 
I've also run into low voltage situations and several times 50 amp outlets with a bad leg.  When I plug the coach in, I look at the Surgeguard lights, if two lights are on, then we're good.  With a permanently install surge guard, it's always sitting there taking care of you with no fuss or muss.  I personally would not be without one.
 
We use Progressive Industries EMS, same principal as Surge Guard. Ours is hardwired with a monitor on the wall...Its saved our bacon a few times with both over voltage and under voltage...Don't leave home without it..
In our 5th wheel we also had an autoformer. It came one a few times when voltage was low but in my opinion it was a waste of my money....
 
Cant Wait said:
I've been reading lots of posts on what people are doing i.e. surge protectors, autotransformers, cheater boxes etc. It seems that for every yes there is a no on the use of these items. I know that the surge guard is a MUST. My issue is that where we camp most the hook-up is 30amp. With the AC set-up my unit (2012 Journey 40U) has, zone 1 has 2 AC's running, and zone 2 has the bedroom AC with no other options. With the AC set on zone 1 the draw is 26amps, this leave very little for anything else.  Is there a way to cut-out the 2nd AC on zone 1 setting? From what I've read the cheater boxes that let you hook into both the 30 & 20amp at the pole to get 50amp don't really work in that the GFI 20 amp breaker keeps tripping. Has anyone used the JTB Power Solutions system that does (according to them) combine the 30 & 20 amp without tripping the 20amp GFI all the time for use with 50amp systems?

I know this is an old thread, but since nobody replied to "Cant Wait's" main question, I figure I'd join and chime in since I have done what he was asking:

Here's a link to the slideshow of my JTB and PI EMS systems:
http://s544.photobucket.com/user/knowles2424/slideshow/JTB

Here's is my JTB Power Solution System installed in my Denali 266RL 34' TT. I also have a Progressive Industries EMS on both the 50AMP Main Panel service and the 30AMP (Technically 20AMP) JTB service. I did not opt for the JTB install kit as I intended to use a 30 amp twist lock power inlet to match my 50 amp main inlet. Also I was running short #10 wires (as you'll see in the pictures, my JTB is mounted inside right next to my main panel), so the install kit is not pictured. I also purchased the yellow 30to20 amp adapter by Marinco (#126A) for adapting the 30A cord to the 20 amp GFI receptacle. I have since also purchased the Conntek 30 to 20a pigtail because at the last site, the 30a and 20a plug were practically touching and it was an awkward and very tight fit. Also the 20a receptacle is "upside down" which makes the 30amp plug face upwards and it was a tight fit to bend it under the metal box lid.

I have a 50AMP TT, but I wanted to be able to incorporate the 20a GFCI receptacle at parks (without tripping the GFI) or use both the 50 and 30 amp connections and this is the only safe way I found. I wanted to run both AC's and a microwave and not worry if the ice machine kicked on too. To me, it was well worth the money and time to install this setup. The JTB automatically "removes" the main A/C from my main panel when the JTB is plugged in so it doesn't count towards my main panel amperage draw. When the JTB is not plugged in, the main A/C is still part of the main panel. It's a "smart" set of automatic relays that won't trip the GFI. It does not trip the GFI because it shuts off the power from the main panel before switching over the 20amp leg power input. The relays let you know when they are switching, thump...thump!

I also chose to add a receptacle to my JTB box which I will use only when the main A/C is turned off at the thermostat. I chose to "JTB" my main A/C rather than my second A/C because that is the ducted unit that we will always be using. It also is the larger unit and pulls more amps, so I isolated it to the JTB which frees up more available amps on the main 50 amp panel for the microwave, uline ice maker, hair dryer, and other appliances. If I did the bedroom AC on the JTB then I am limiting the amount of time that I actually benefit from the JTB and I could still only pull 30 or 50 amps on my main line. Doesn't make sense for the MFG of the JTB to be recommending the second AC be isolated. They need to rethink that advice.

The JTB is a fancy auto-transfer switch. I don't mean that in a negative sense, but it does not truly provide 70 amps to a 50 amp coach or 50 amps to a 30 amp coach. That is slightly inaccurate. It does remove one breaker of your choice from the main panel. In my case my main AC will pull as high as 16 amps (reading on PI EMS), so in my case it frees up 16 amps for other use on my main panel. In my case it makes my 50amp TT capable of 66amps max. The other "unused" 4 amps are not added to the 50 amp main panel. I hope that makes sense... it did in my head.

Overall, I love the JTB. I think I enjoyed the wiring and "project" aspect of it as much or more as I do the actual benefit it provides. Sometimes I think the main reason I go camping is just to test out my new mods and come up with new mods to do when I get home.

Also, I ordered straight from the MFG by calling the #. Had to leave a message as they never answered for days, but then when I left a message they called back immediately.

Hope the pictures and my opinion help if you're still considering getting one.
 
And if you already got one, please share how you installed it and your experience with it....

 
John Hilley said:
The JTB Power Solutions box isolates one AC from the main breaker panel of the RV and connects it directly to the 20 amp receptacle on the power pedestal. This will work fine as long as the 20 amp receptacle is wired separately from the 30 amp receptacle as it should be if wired correctly. In some campgrounds it may be derived from the 30 amp breaker and then would not work as you would again be exceeding 30 amps with certain combinations of loads. It will resolve the GFCI problem of some of the 20/30 amp to 50 amp combiner adapters.

I am no electrician, but I was told by a general contractor (also not an electrician) that NEC would require that the power pole in a camp site be run with large enough gauge wire to support all available receptacles, i.e. 100 amps (the 50+30+20) for a 50 amp site or large enough wire to support 50 amps (30 and 20 receptacles). I would be surprised if they were allowed to wire with say #8 wire instead of #6 (or whatever the appropriate sizes would be.. 8? 6? 4? 2?) on a 30 amp site with a 20 amp additional receptacle, and it only be good enough to support one of the outlets on it. Nothing says you couldn't use the 30 amp to it's max and then plug in an electric outdoor grill to the 20 amp... at least at the sites I've been to. I'm not saying you're wrong by any means, I'm just hoping maybe someone else, especially an electrician, can clarify.

I would hope that the receptacles would be wired separately or at least with thick enough wire to support the cumulative amps each outlet is rated for.
 
John Hilley said:
The 50amp, 30 amp, 20 amp pedestals are wired as 125 amp.

What about the 30 amp sites with a 30 and 20?

Do you believe code generally requires that these posts are wired with appropriate gauge wire to handle a camper actively pulling 28-30 amps from the RV30 plug and another appliance plugged into the 20 amp plug pulling 15-18 amps?
 
Cant Wait said:
I know that the surge guard is a MUST.

Perhaps a MUST if you make your living selling them.

Otherwise . . . No one has ever suggested that I need one in my home where I live 24/7; much less my RV where I spend even less time connected to the elusive mysterious surge-demon.

Wow!! Talk about living on the edge: 70 years uneventful years living in houses without surge-guards; and gasp!! a further 40 uneventful years of RVing without benefit of such awesomely wondrous Protection! Gasp!

Can you spell:  S-N-A-K-E  O-I-L??
 
Stan Birch said:
..Talk about living on the edge: 70 years uneventful years living in houses without surge-guards; and gasp!! a further 40 uneventful years of RVing without benefit of such awesomely wondrous Protection! ..
You're a lucky guy.
 
I was told by a general contractor (also not an electrician) that NEC would require that the power pole in a camp site be run with large enough gauge wire to support all available receptacles, i.e. 100 amps (the 50+30+20) for a 50 amp site or large enough wire to support 50 amps (30 and 20 receptacles).


The contractor is wrong.  It's a fact that the wiring must "support" all the receptacles, but supporting them does NOT mean that each will be able to draw the full rated amperage. That's not even true in residential wiring. For example, if you have two household 15A outlets on a branch circuit, the wiring is still designed to handle a total of 15A, not the combined max of 30. The circuit breaker will be 15A as well, preventing a wire overload if too many loads are plugged to the available outlets.

There are formulas for estimating average combined loads where there are multiple "drops" on a single circuit and the NEC allows the use of average rather than peak loads to determine wire sizes and related components.  Even the individual rated load, e.g. 30A, is considered a peak load and the actual sustained load rating is 80% of that. That means the 30A outlet on the pedestal is actually designed only for an average of 24 amps per hour. That's why they get hot if your RV is drawing 25-29 amps for very long.

I believe you will find that most 50/30/20 pedestals are supplied by a single 240V/50A circuit and that the 30A and 20 A outlets are tied to that. Situations may vary according to local electrical codes, though, because the NEC is only a recommended standard and each state and locale adopts their own version of it with the modifications they feel are desirable. The code also changes almost yearly but communities don't change their local building code laws anywhere near that often.
 
Gary RV Roamer said:
..
I believe you will find that most 50/30/20 pedestals are supplied by a single 240V/50A circuit and that the 30A and 20 A outlets are tied to that. ..
That's how I wired my two pedestals; I think I used 10 gauge wire since it was a short run from the load center to the pedestals.
 
Wow!! Talk about living on the edge: 70 years uneventful years living in houses without surge-guards; and gasp!! a further 40 uneventful years of RVing without benefit of such awesomely wondrous Protection! Gasp!

Well, I have to agree with Stan. In my opinion, calling something a "must" is a far cry from saying it's "good to have". Many people can and do enjoy camping without having one and encounter no more surge risk than in their homes. However, the more different campgrounds and campsites you visit, the greater the risk of encountering that one that has a problem.  It's the old "Your mileage may vary" problem.

I will also add that I have a whole house surge protector on our stick home (as well as the RV).  Living in the lightning capital of the USA (Florida), surge protection is indeed a wise thing to have at home.
 
I agree that a lot of surge protection, especially for consumer electronics is snake oil. However, the EMS features of some electrical protectors are beneficial. Probably the one feature that can really help in an RV park is the low voltage cut out. Also useful, but not as frequent is high voltage cut out. Also their ability to verify correct neutral and ground when plugging in.
 

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