With the unknowns of connecting to campground electricity and PowerTech generator voltage regulator problems producing 160-volts where 120-volts is normal, a high / low voltage protector has become a required device.
So, the question to be answered is where to install a hardwired EMS?
There are multiple locations that supply AC electricity, each with their own risks to think about:
1) Shore power, with the most anomalies, like 1,000 volt surges, high & low voltages, etc. Very high momentary surges from lightning, etc are rare and VERY hard to protect against. It is possible that a very high voltage surge could even damage an EMS preventing it from functioning.
2) Generator with our new voltage regulator concerns that can put around 160-volts where 120-volts is normal. EMS does a great job protecting this.
3) Inverter, with no known common voltage problems.
INSTALLATION CHOICE ONE:
1) Install an EMS device on the Romex cable that connects the 50-amp double-pole main-breaker on the main-circuit-breaker panel located on the front of the bed TO the transfer switch at the other end of this cable. This would prevent high/low voltage from shore or gen from reaching the main breaker panel, protecting all coach loads.
2) This method may be the #1 choice of where to install a single EMS.
3) There are two devices that are not protected with this setup:
a. Transfer switch: which would likely not be damaged by higher gen voltage while it passes high voltage to the EMS but could be damaged by shore lightning surges.
b. Generator windings: that in the rare situation a shore lightning surge catastrophically damages transfer switch allowing current to backfeed to generator.
INSTALLATION CHOICE TWO:
1) Install an EMS on the cable that connects the shore power cord to the transfer switch.
2) This used to be the alternate #1 choice where to install a single EMS.
3) This protects from notorious campground shore cable anomalies, protecting coach loads, transfer switch and rare generator problems from a damaged transfer switch.
4) But does not protect from generator high voltage.
5) Choice Two also describes how a plug-in EMS device operates.
INSTALLATION CHOICE THREE:
1) Install an EMS on the cable that connects the generator Romex to the transfer switch.
2) Don't know of anyone using this location.
3) This puts maximum protection on generator high voltage problem, including transfer switch and coach loads.
4) But does nothing for campground cable problems.
For decades we have had a Progressive Industries EMS using INSTALLATION CHOICE ONE, then a few years ago added a 2nd EMS as INSTALLATION CHOICE TWO.
One of the new kids on the EMS block is Hughes EPO quite similar to our PI-EMS, but without PI-EMS remote's emergency bypass option. I like the Hughes unit for its Bluetooth (which may not work as well as the PI-EMS remote meter) and lower cost.
Some Foretravel's have a 2nd transfer switch that is not involved in determining where to install an EMS. The 2nd only connects inverter-output 120-v OR a single-pole breaker in the main breaker box TO the inverter breaker panel.
Those coaches without this 2nd transfer switch use the built-in transfer relay in every inverter/charger, that can limit amps to inverter panel when on shore or gen power. The 2nd transfer switch allows higher amps by bypassing inverter when on shore/gen.
Question 1 will the ats holding coils be damaged by an overvoltage or just pull less amps? IDK
I have one Progressive Industries EMS installed in your choice number two behind the cord reel in the utility compartment. I moved it there after the original install location below the bed ahead of the transfer switch was problematic because of a noisy EMS (60 cycle hum). I have a second unit which I will install in choice number three for protection against generator voltage issues. This one, I will put under the bed in spite of my experience with my first under the bed installation. First of all, the noise won't be an issue because the sound of the generator will drown out any 60 cycle hum. Second, we have never yet gone to bed with the generator running. This covers everything put an inverter failure which results in over or sustained under voltage. The Magnum documentation says that the inverter has built in protections against that sort of eventuality, but...
Don
Don,
With your coach having the inhouse/FT made quite box have you ever thought about mounting your 2nd EMS up on the back side of the generator box? You hook in on the wires right off the generator and then you run the remote wiring up to the dash so you can watch while traveling.
Mike
This post should be pinned/stickey!
Kudos on an extremely easy to understand post and reply. This can be a confusing subject for newbies but critical to consider given the cost of damage caused by bad shore power or generator over voltage....both of which we've experienced during our years of camping.
We used Choice One and fortunately have no discernible hum to deal with. Also makes any service easy to access for the PI EMS.
Our coaches are similar, I used choice one. The generator can deliver bad electricity same as shore power. I made a small platform for the EMS. That piece of wire is stiff to work with, but it is doable. My EMS had a loud hum, but Progressive sent me a new relay that solved the problem after I complained.
Question. If I choose option 1 to be cost effective and still protect from both gen and 50 amp power post, can I still use something like the Hughes blue tooth portable on the post? It seems I remember reading not to connect two protectors on the same line or was that two ground fault protectors?
I know when we took our 'hit' (pre EMS), it fried both power cable ends as well as the connection in the wet bay, so, I'd think a 'EMS Lite' at the pedestal would be a good idea. BTW, we have the Progressive pedestal mount, which works for either 50 or 30 amps.
Mike,
Our 99' doesn't have a quiet box in the usual sense, i.e., an enclosing sheet metal box. By in house/FT made quiet box, I assume you mean the insulation clad walls that comprise the generator compartment. Replacing the deteriorating insulation with Soundown (the same as I used for the engine compartment) which lines the generator compartment on the back, sides, and top is near the top of my project to do list. I had originally thought about putting it near the generator, but for once, I may take the path of least resistance since the noise won't be a factor. Who knows? The new one may be as silent as the ones others have installed under their beds. My first one failed and the one I bought to replace it was much quieter. The one I have waiting to be installed is the free replacement I got from Progressive Industries for the failed unit. I may even just put it under the bed for now and when I get around to the generator compartment insulation, rethink the issue. I have a cat 6 cable (overkill for the EMS display, but I ran it just in case while doing something else) already run to my coach information panel from the transfer switch box under the bed and the display is installed above the shore power display (see attached photo), so adding the generator EMS could be done in short order and will be done while we are on the road.
Don
Yes, There is a great mounting spot on the back of that panel. Next time you are under there looking at your front ride height valve just look to the front and you will see the area I am talking about.
Mike
RE: "can I still use something like the Hughes blue tooth portable on the post?
No problem running multiple over under volt ems that I can see. And using the Hughes is a good idea.
RE: "I have a cat 6 cable for the EMS display"
Great idea to use cat 6 Ethernet cable to mount the PI-EMS remote a long distance. To 'convert' the RJ-45 connector to the narrower RJ-11, use a RJ-45 female-female joiner. We also ran several CAT-6 cables from batteries to kitchen display panel, now using their twisted-pairs for a couple of shunt meters.
Another similar idea is to use a 4-wire jacketed cable connected at both ends to old fashioned square telephone junction boxes with a built-in RJ-11 female connector. Then use a short telephone RJ-11 male-male cord (normally used on wall phones) to connect junction boxes to Progressive Industries parts. The jacketed cable has the advantage of being run through smaller holes, etc without any terminated ends, and and the cable wire-size can be larger & stronger than Cat-6.
Surface Mount Box with Screw Terminals - RJ11 - 4 Conductor | Computer Cable... (http://bit.ly/2TU7pkq)