EMS - internal vs external pros and cons

[Lady Fitzgerald]

What I don't understand is why people are so worried about the difficulty of transferring an internally mounted EMSS to a new camper. I realize they cost a lot (almost $350 for a 50A internal model) but why not just leave the old one, which may have MOVs on their last legs, use it as selling point for the old RV, then install a new unit in the new RV. Until you do sell the old RV, you can be enjoying the benefits of the internally installed EMS. Another $350 is a drop in the bucket compared to cost of a new RV.

[sennister]

Originally Posted by KillerIsMe

I bought the portable simply because I'm a new guy and there is much to learn, so the portable being simpler I have one less thing to think about.

That being said I've seen the Youtube videos for the permanent install and it doesn't look too difficult so I'll be going down that road either in the fall or next spring (your install method is genius by the way and that's how I'll go). I'll either sell the portable or, more likely, keep it as a backup.

Anyways my question for you is, would it make any sense to buy a dog bone or an adapter to plug into the pole and then plug the PI into the bone? I'm thinking if the box fries something it would be the bone.

Well thanks but I won't take credit for my installation method. I don't know where I saw it first but it isn't my idea and many people have done it this way. I am just glad to pass it on. It reduces the amount of time standing on your head during the install on a 90F day to a minimum. Even if you never remove it. Who knows your next camper or RV may be a 50A unit so the 30A EMS is of no use to you.

As for the adapter. Here is my biggest issue. If you are talking about plugging into a 50A well you need the dog bone anyhow. If you are talking about plugging the 30A into a 30A outlet with a dog bone, well I don't know that I have ever seen one. You could do a dog bone that does 30A to 30A twist lock and then 30A twist back to normal 30A. Or 30A to 50A and back to 30A. That seems like more trouble than it is worth and then you are going through so many adapters and dog bones that the EMS is now laying in the mud.

I would make sure the outlet shows no sign of melting. Periodically feel the plug and make sure it isn't getting too hot. More so when running AC on those hot days. I wouldn't like the idea of the EMS hanging all of its weight off the outlet on the pole. Maybe have some form of bungee or strap to take some of the weight off as you want to keep that plug fully seated. I don't have a portable one so I don't know how heavy it is but I would still do something to support it. Of course that opens the challenge of what you use at one place may not work at the next.

[sennister]

Originally Posted by Lady Fitzgerald

What I don't understand is why people are so worried about the difficulty of transferring an internally mounted EMSS to a new camper. I realize they cost a lot (almost $350 for a 50A internal model) but why not just leave the old one, which may have MOVs on their last legs, use it as selling point for the old RV, then install a new unit in the new RV. Until you do sell the old RV, you can be enjoying the benefits of the internally installed EMS. Another $350 is a drop in the bucket compared to cost of a new RV.

Also, if you have a 30A unit like I have now, maybe the next camper is a 50A then it is worthless. Or if you have a 50A maybe you downsize to a 30A unit.

I mainly went with the twist lock install method to make it easier to install. I could do much of the touchy wiring from the comfort of my work bench. Then just install the plug ends in the awkward position in the camper while in the heat. It also opened the ability to completely bypass it should I ever need to and the ability to take it out and sell it separate. Odds are I will trade in our camper and not sell it. On trade an EMS will not increase the trade in value and the separate sale can offset the cost of a new EMS if one is needed. If not just install it in the new rig. I agree that $350 is a drop in the bucket but if I can sell it used for $200. Well that is still $200. I am not a 1%er. $200 is worth 10 minutes of my time to pull it out. If it were 4 hrs of my time it would be a different story but 10 min I will do.

[KillerIsMe]

Originally Posted by sennister

Well thanks but I won't take credit for my installation method. I don't know where I saw it first but it isn't my idea and many people have done it this way. I am just glad to pass it on. It reduces the amount of time standing on your head during the install on a 90F day to a minimum. Even if you never remove it. Who knows your next camper or RV may be a 50A unit so the 30A EMS is of no use to you.

As for the adapter. Here is my biggest issue. If you are talking about plugging into a 50A well you need the dog bone anyhow. If you are talking about plugging the 30A into a 30A outlet with a dog bone, well I don't know that I have ever seen one. You could do a dog bone that does 30A to 30A twist lock and then 30A twist back to normal 30A. Or 30A to 50A and back to 30A. That seems like more trouble than it is worth and then you are going through so many adapters and dog bones that the EMS is now laying in the mud.

I would make sure the outlet shows no sign of melting. Periodically feel the plug and make sure it isn't getting too hot. More so when running AC on those hot days. I wouldn't like the idea of the EMS hanging all of its weight off the outlet on the pole. Maybe have some form of bungee or strap to take some of the weight off as you want to keep that plug fully seated. I don't have a portable one so I don't know how heavy it is but I would still do something to support it. Of course that opens the challenge of what you use at one place may not work at the next.

Thanks Sennister. You and I have similar models - you the 25BH and me the 23BHM. My water heater and main electric is also under the bottom bunk back in the corner. Only difference is your bunks being doubles and mine singles. That is one tight space back there. I'm waiting to tackle the install until the weather is cooler and will use the portable this summer. The portable is big, by the way. Surprisingly so, so the bungee idea is a great one. Thanks again for sharing the knowledge.

[sennister]

Originally Posted by KillerIsMe

Thanks Sennister. You and I have similar models - you the 25BH and me the 23BHM. My water heater and main electric is also under the bottom bunk back in the corner. Only difference is your bunks being doubles and mine singles. That is one tight space back there. I'm waiting to tackle the install until the weather is cooler and will use the portable this summer. The portable is big, by the way. Surprisingly so, so the bungee idea is a great one. Thanks again for sharing the knowledge.

When shopping for our camper we had narrowed the options down to the 25BH and the 23BHM. We liked the two entry door option of the 23 but the additional storage up front, outdoor kitchen had us leaning toward the 25BH. Then the fact that they were the same price was the final factor.

I never opened up the bunk area on your floor plan. On ours under the lower bunk, 1/2 of the space is taken up by the outdoor kitchen. Of the remaining 1/2 it is split between some storage area and the back part is walled off for the water heater. The access to the forward storage area is easier but I didn't want the EMS in there taking up space. Not to mention exposing wires to abuse of stuff bouncing around back there. The back area has a small wood opening so that I can access the water heater bypass when winterizing the unit. By taking out maybe 8 screws I could open this entire area up to make wiring go a lot easier. There was plenty of room to mount the unit to the floor back there and that is near where the power comes in anyhow and where they mounted the metal box where it transitions from the outdoor power cord to indoor wiring. My power cord used to stuff under the shower area which would be in that back corner of the camper. For us it wasn't a big deal scouting out where to put things since we store our camper at our house year round. I just waited for a cooler day and went out and planned out the install. I guess one of the bigger issues is going to be if you go with the unit that has a remote display and if so where are you going to mount it? I initially wanted to put it next to my thermostat but there is no easy way to route the wire there. Since my outdoor kitchen is under the bunk, I just fished the wire (10' telephone cord) along the water lines going out there. This way I can see it from outside which is nice when hooking up. I guess the only issue with that is if something goes bump in the night I have to go outside to see what the issue is. My other thought was to mount it along the bottom of the bunk but I was concerned about the kids stepping on it getting in and out of bed because it is a surface mount. If I really wanted to they have an option to add a second display and I could still do this but I don't see the need.

If you really can't come up with a plan on where to mount the display then I would consider getting the cheaper one without the remote display. You would need to access it if there is a problem where the power doesn't kick in but depending on how hard it is to get to the area in your camper it might not be a big deal. I will say that if you go with the cheaper one and you boondock at all, check to see if your generator has a floating ground. Pretty much all of the Yamaha and Honda inverter generators do. If it does you either need to bypass the EMS or make or buy an adapter to bond the neutral to ground or the EMS will throw an error that the ground is open and it won't let power into your camper. To do the bypass if you have the remote display, you just flip a switch on the remote display. If you have the less expensive one without the display you can get an optional or make a bypass switch or you have to open it up and move a wire or completely bypass the EMS by swapping around the twist locks taking it out of the circuit. If you don't use a generator then it doesn't matter as much.

[KillerIsMe]

Originally Posted by sennister

When shopping for our camper we had narrowed the options down to the 25BH and the 23BHM. We liked the two entry door option of the 23 but the additional storage up front, outdoor kitchen had us leaning toward the 25BH. Then the fact that they were the same price was the final factor.

I never opened up the bunk area on your floor plan. On ours under the lower bunk, 1/2 of the space is taken up by the outdoor kitchen. Of the remaining 1/2 it is split between some storage area and the back part is walled off for the water heater. The access to the forward storage area is easier but I didn't want the EMS in there taking up space. Not to mention exposing wires to abuse of stuff bouncing around back there. The back area has a small wood opening so that I can access the water heater bypass when winterizing the unit. By taking out maybe 8 screws I could open this entire area up to make wiring go a lot easier. There was plenty of room to mount the unit to the floor back there and that is near where the power comes in anyhow and where they mounted the metal box where it transitions from the outdoor power cord to indoor wiring. My power cord used to stuff under the shower area which would be in that back corner of the camper. For us it wasn't a big deal scouting out where to put things since we store our camper at our house year round. I just waited for a cooler day and went out and planned out the install. I guess one of the bigger issues is going to be if you go with the unit that has a remote display and if so where are you going to mount it? I initially wanted to put it next to my thermostat but there is no easy way to route the wire there. Since my outdoor kitchen is under the bunk, I just fished the wire (10' telephone cord) along the water lines going out there. This way I can see it from outside which is nice when hooking up. I guess the only issue with that is if something goes bump in the night I have to go outside to see what the issue is. My other thought was to mount it along the bottom of the bunk but I was concerned about the kids stepping on it getting in and out of bed because it is a surface mount. If I really wanted to they have an option to add a second display and I could still do this but I don't see the need.

If you really can't come up with a plan on where to mount the display then I would consider getting the cheaper one without the remote display. You would need to access it if there is a problem where the power doesn't kick in but depending on how hard it is to get to the area in your camper it might not be a big deal. I will say that if you go with the cheaper one and you boondock at all, check to see if your generator has a floating ground. Pretty much all of the Yamaha and Honda inverter generators do. If it does you either need to bypass the EMS or make or buy an adapter to bond the neutral to ground or the EMS will throw an error that the ground is open and it won't let power into your camper. To do the bypass if you have the remote display, you just flip a switch on the remote display. If you have the less expensive one without the display you can get an optional or make a bypass switch or you have to open it up and move a wire or completely bypass the EMS by swapping around the twist locks taking it out of the circuit. If you don't use a generator then it doesn't matter as much.

The way ours is set up, the main power comes in under the bunk. Our bunks run across the back and are adjacent to the business side of the camper so the water heater and power cord are in a little compartment under the lower bunk accessed through a small panel in the corner. Under the rest of the bunk is another fairly big storage area accessed from the bunk and also from the outside by way of a door on the back wall. Seems convenient, and I guess it is except the bunks are between the rear wall and bathroom wall. I can get back in there but it's a little narrow. Anyways, the big orange wire comes in and runs along the bathroom wall into the large storage area, and from there it disappears under the wardrobe closet in the opposite back corner. I didn't find the little metal transition box and assume it's under the wardrobe.

So if I'm understanding you correctly I would cut the main orange power wire back in the small water heater compartment, wire up the PI (using the ingenious twist plugs ) and mount it inside that compartment (plenty of room on the floor and on the bathroom wall). I can run the display cord into the larger compartment and mount it on the lower bunk front wall out of the way. Does that sound right?

Just one more question: since I can't find the transfer box and so would mount the PI before the box, does that mean I can't use a generator because I won't be able to bypass the surge protector?

Last thing: Twins are better than I thought they'd be this year. Big Sexy pitched pretty well last night but the guy is 44 - he ran out of gas early. We're Yankees fans here.

[sennister]

Originally Posted by KillerIsMe

The way ours is set up, the main power comes in under the bunk. Our bunks run across the back and are adjacent to the business side of the camper so the water heater and power cord are in a little compartment under the lower bunk accessed through a small panel in the corner. Under the rest of the bunk is another fairly big storage area accessed from the bunk and also from the outside by way of a door on the back wall. Seems convenient, and I guess it is except the bunks are between the rear wall and bathroom wall. I can get back in there but it's a little narrow. Anyways, the big orange wire comes in and runs along the bathroom wall into the large storage area, and from there it disappears under the wardrobe closet in the opposite back corner. I didn't find the little metal transition box and assume it's under the wardrobe.

So if I'm understanding you correctly I would cut the main orange power wire back in the small water heater compartment, wire up the PI (using the ingenious twist plugs ) and mount it inside that compartment (plenty of room on the floor and on the bathroom wall). I can run the display cord into the larger compartment and mount it on the lower bunk front wall out of the way. Does that sound right?

Just one more question: since I can't find the transfer box and so would mount the PI before the box, does that mean I can't use a generator because I won't be able to bypass the surge protector?

Last thing: Twins are better than I thought they'd be this year. Big Sexy pitched pretty well last night but the guy is 44 - he ran out of gas early. We're Yankees fans here.

So you have your camper power cord which is the thick black cord. This is the part that is outside your camper. You open the little door and stuff it in the hole. That door is the mouse hole that most people refer to. That is unless the mouse hole design was eliminated in your camper with either a conversion which is what I did or maybe it shipped with the twist lock style port on the outside of the camper and your outdoor cord is just a big heavy extension cord. Pretty much all the Jaycos we looked at were the mouse hole design where the power cord is stuffed into the hole and it just piles up somewhere like under a bunk or under the bathroom vanity.

Inside the camper you should be able to find where this big black cord goes into a metal double gang electrical box with a blank plate on it and you will see 10 gauge Romex coming out. If you open it up you will see the wires are connected by wire nuts. You are right that the romex should be orange. The jackets all used to be white but a while back they started color coding them so inspectors could quickly identify the gauge of the wire to make sure houses and such are wired right at the panel. White 15A - 14ga, Yellow 20A - 12ga and Orange 30A - 10ga. This electrical box will be located somewhere very close to where the power comes into the camper. The orange romex will run from the metal box to the converter. Mine was roughly located under the wall dividing the bunks from the bathroom if you look at the floor plan of the 25BH and the power comes in on the side under the shower which is where the outside power cord was stored if stuffed in the mouse hole. From the metal box the romex goes under the bunks, under the cabinet, then fridge which is were my converter is located. Since this is the only 125V 30A run in the camper, it should be the only orange romex that you will find. Coming out of the converter everything should be white romex going to the outlets, AC and such.

If you can't see your metal box you just want to make sure you wire it the right way. Odds are Jayco did waste a ton of wire running that 10 ga romex all over the camper and you know where the power comes in and where the converter is which is where it is going. It will be a relatively straight shot between the two as much as they can. You can cut that orange romex anywhere between the metal box and the converter you want to install the EMS. Do so in a place with enough room to mount the EMS which you indicated is under the bunk near the water heater which is where I also put mine. The biggest thing you need to make sure of is the direction of flow which as I said is easy to see if you can find the electrical box or you can figure out based on the location of the power entrance and the location of the converter. The converter is the box where your circuit breakers are for 110V stuff and the 12V fuses. There is probably a fan on it that you hear running. You want to make sure to put the female twist lock on the orange romex that goes to the electrical box and the male twist lock on the orange romex going to the converter. The reason for this is that lets say the camper was plugged in, you have an issue and decide to physically bypass the EMS so you disconnect the twist locks. If you had a male connector on the electrical box side, the conductors, which would be hot, would be exposed. It is kind of like having an extension cord with the prongs on both ends. Sure it would technically work but it isn't the safest thing. Does that make sense? On the EMS the input gets the male plug and the output gets the female plug.

As for the remote display it can go anywhere. I thought of the "wall" along the bottom of the bunk. In the 25BH I was concerned about the kids hitting it and ripping it off as they climb in and out of bed. Maybe on your camper you can mount it off to the side more to protect it better. It is a surface mount and I thought of trying to recess it by cutting an opening in the wall because it is pretty thin. Then I thought of just putting it out in the kitchen area outside which is what I did. It doesn't matter but because it is a phone cord you are limited to 10' or so and they have the square RJ-11 connectors on it so you have to drill a hole quite a bit bigger than the wire to fish them through any opening. Also the wire plugs into the bottom of the display not the back so you have to deal with that.

As for your question about the transfer box and generator use. There isn't a transfer box. The metal box I keep talking about is like I mentioned above just a double gang electrical box with a blank plate on it that has the outside power cord going in one hole and the orange romex coming out the other side. There is nothing inside of this other than some wire nuts connecting the white, black and ground together with its respective pair. If you have done home remodeling work it is a box just like you would find in a house where your outlets are mounted. It is just there to protect the wire nuts. It is also grounded so if a wire nut fell off it would short out and should trip the breaker on the post outside. So since you are cutting the orange wire between this electrical box and the converter you can still use a generator and bypass.

I should clarify the term bypass just to make sure it is clear. When I am talking about using the bypass on the remote display (this link is for the optional second display but you get the idea) on the more expensive EMS or with the optional bypass switch in the less expensive EMS that doesn't come with the remote display, I am talking about a physical switch on the little box. If you flip the switch to bypass you are bypassing the EMS portion of the system. You still have a surge protector in place. It just doesn't look for things like high/low voltage, open grounds and such. All the things that make the EMS more expensive. That is all you have to do if you use a generator. Or you can make an adapter for a couple bucks that plugs into one of the unused 110v outlets to bond the ground to neutral so the EMS is happy.

The other bypass that I mentioned is possible because of the twist lock plugs. You can open up whatever you need to do in order to get to the EMS, unplug the twist lock plugs from the EMS and hook the two together like if you were selling the camper and wanted to keep the EMS. This fully bypasses everything since the EMS is no longer physically hooked up. Of course if you did this you wouldn't have surge or EMS protection. Lets say a storm blew through and there was a lighting strike that fried the surge board in the EMS. You order a new one and it will be at your house when you get home. But now the weather is beautiful so little chance of storms and you want to risk plugging in for a few hours to charge your house batteries. You could completely bypass the EMS and hook up simply by disconnecting those twist locks and plug in for a bit. If we are just talking doing generator use, I would do the bypass switch method. If you had a more serious problem because the EMS took a hit, then you have the option to completely remove it from the system.

One other thing that I mentioned briefly but think I should mention again to give it more attention. When you hook those twist locks together, run some electrical tape around the plugs to hold them together. Bouncing around back there can cause them to untwist. Not common but very possible. If they untwist they may not make full contact and this can cause the plug to overheat. Just like with the melted outlet on the pedestal. Electrical tape will make sure they stay locked together and is easily removable should you ever need to do the full bypass method at some point. You don't have to go crazy but a little tape will help. I keep a roll in my tool kit that stays in the camper. I wouldn't use duct tape for this if for no other reason that it would leave residue and is overkill.

Yeah Twins are doing better than I thought this year. We are kind of tired how they demanded all this money for a new stadium and how they would then invest in building the team if it was built. They get the new stadium a couple years ago and forgot about their part of the agreement. We would rather go see the St Paul Saints which is the minor league team. It is a lot more fun at those games anyhow. Great seats are so much more reasonable and you can see something rather than watching ants play baseball. Between innings they do all kinds of crazy stuff which keeps the kids entertained.

[KillerIsMe]

Originally Posted by sennister

Inside the camper you should be able to find where this big black cord goes into a metal double gang electrical box with a blank plate on it and you will see 10 gauge Romex coming out. If you open it up you will see the wires are connected by wire nuts. You are right that the romex should be orange. The jackets all used to be white but a while back they started color coding them so inspectors could quickly identify the gauge of the wire to make sure houses and such are wired right at the panel. White 15A - 14ga, Yellow 20A - 12ga and Orange 30A - 10ga. This electrical box will be located somewhere very close to where the power comes into the camper. The orange romex will run from the metal box to the converter. Mine was roughly located under the wall dividing the bunks from the bathroom if you look at the floor plan of the 25BH and the power comes in on the side under the shower which is where the outside power cord was stored if stuffed in the mouse hole. From the metal box the romex goes under the bunks, under the cabinet, then fridge which is were my converter is located. Since this is the only 125V 30A run in the camper, it should be the only orange romex that you will find. Coming out of the converter everything should be white romex going to the outlets, AC and such.
plug.


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Ah, that's why this has been confusing to me. I don't have a mouse hole - the shore power cord IS just a big extension cord that disconnects and gets tossed in a storage compartment. Being my first go-around I just assumed all Jaycos were like ours. So on ours rather than the power cord coming through the trailer wall and connecting to the orange Romex inside the little metal box, the orange Romex is attached to the outlet on the outside wall that the power cord plugs into. So like a moron I was following the orange wire looking for a metal box when in fact the orange wire no doubt goes right to the converter, which like yours is under the refrigerator.

Man I am so sorry for bothering you about all this. The business with the mouse hole/detachable power cord was the key to my stupidity. Thanks for your help Sennister.

[sennister]

Originally Posted by KillerIsMe

Ah, that's why this has been confusing to me. I don't have a mouse hole - the shore power cord IS just a big extension cord that disconnects and gets tossed in a storage compartment. Being my first go-around I just assumed all Jaycos were like ours. So on ours rather than the power cord coming through the trailer wall and connecting to the orange Romex inside the little metal box, the orange Romex is attached to the outlet on the outside wall that the power cord plugs into. So like a moron I was following the orange wire looking for a metal box when in fact the orange wire no doubt goes right to the converter, which like yours is under the refrigerator.

Man I am so sorry for bothering you about all this. The business with the mouse hole/detachable power cord was the key to my stupidity. Thanks for your help Sennister.

That makes sense. When we were shopping we bought at the RV show so while the Jay Feather 23BHM was on our list, we never actually stepped foot in one. They did have a White Hawk version. I don't remember if it had the mouse hole or the extension. Like I said, I converted mine over to the extension version. While it is a bit of a pain to store the cable. It is a lot nicer than the mouse hole. That also explains why you don't have the metal box. There is no need for it. The only reason is to protect the connection from the outdoor cable to the Romex. Mine is actually like yours in that I pulled out all the outdoor cable and ran Romex right to the outlet mounted on the wall of the camper. I did run it into the metal box still but I could have just put the female twist lock on the EMS side.

Not an issue with the questions. Glad I could help. This is my first Jayco. We did have a Dutchmen that we had before this camper which also had a Mouse Hole. While I knew some campers came with the external cord like yours, I thought it was more common on more expensive units.

[blujay40]

Not all that relevant to the OP's original question, but it is something related so I thought I would post it.

I ran across a post that asked the question of whether they could purchase a 50 amp EMS to use on their current 30 amp unit because they felt they would be upgrading to a 50 amp unit in a few years and would they have any issues or would there be any risks in doing so.

So the question was posed to PI directly and the answer surprised me. They offer two different versions (30/50) solely based on cost sensitivity of the RV community and that if you only needed a 30 amp unit, you could buy one cheaper than if PI offered 50 amp units exclusively and just advised you to get an adapter/dogbone. This was their response to me.............

"The RV community is very sensitive to pricing. People will pay many dollars for a vehicle and then balk at paying $326 dollars for a PT30 to protect their RV. We as a rule, we tell potential customers to buy a device that matches the coach’s electrical system. If they mention something like “ Next year, we are upgrading to a fifty amp coach “ , I will suggest getting a 50A device and use adapters. So the answer is that market factors drive us to manufacture various models."

I wish I had known this before I bought my first one because it was only a year later that we moved from a 30 amp to a 50 amp RV and now my 30 amp EMS is delegated to an emergency backup.

So for those that currently have 30 amp RV's and may be upgrading in the future, you might want to consider purchasing a 50 amp unit now and iuse adapters/dogbones instead of having to purchase yet another EMS when you move to a 50 amp RV.