EMS

[Iowa Dave]

Hi Willy
Don’t let It get you down, I don’t want to hear you’ve got “The St.Louis Blues.”.
Iowa Dave

[WillyB]

Originally Posted by Iowa Dave

Hi Willy
Don’t let It get you down, I don’t want to hear you’ve got “The St.Louis Blues.”.
Iowa Dave

Ha!

We're very excited and can't wait until this October. Looking forward to signing the build sheet in a few months.

Our luck has been pretty good on the lead time. It started out at June 2023.

My unlucky in love brother tattooed Albert King's lyrics "If it wasn't for bad luck I wouldn't have no luck at all" under his left bicep.

[oreo]

Great idea to have a built in EMS, I have one just turn off the EMS unit off when running my Honda 2200 Gen instead of buying a Neutral-Ground Bonding Plug .

[Iowa Dave]

We bought the neutral ground bonding plug. EMS “boots up” just like you’re on shore power. Takes a couple minutes.

It’s only money. I can sell an axe or a fishing pole and make more. Bitcoin who needs it. Boondocker bitcoin, a new concept in camper currency. You heard it here first,
Iowa Dave

[HABBERDABBER]

Coffins don't have pockets.
Spend that money.
Willy B. Your words. "We are 9 months away from our completion date and are debating the pros/cons of a $70 Portable Surge Protector vs. the $350 ETI installed EMS. I get the built-in vs portable debate but at nearly $300 I'm looking for a betting understanding of the ETI EMS."

Spend that money,

They are a lot more convenient than a plug in, that's for sure. Ask around, but I suspect they're worth the extra $$$ over time.

A grounding plug takes $3.50 and 5 minutes to make. I did that. That would not be my primary reason for an EMS. My used rig came with an EMS, and I'm glad it did.

[Iowa Dave]

Years ago a guy gave me a Boy Scout hatchet. It was in kind of rough shape. I reworked the handle, cleaned up, sharpened and painted and reset the head. And I’ve used it quite a bit over the years. Last week he called and mentioned he’d broken the handle on his old axe using it to chop ice forming nightly in his horse tank. He hated the thought of buying a new one, or fishing the head out of the tank and getting a new handle. Down in the shed, in my axe bucket, an old, used but serviceable double bit. My logging days over, I delivered it to his porch while he was gone. He called and told me an axe elf had visited. That’s friendship and it’s worth more than money to me.
And Rita commended my tiny act of downsizing.
Iowa Dave

[WillyB]

We will be about 50/50 campground vs boon docking with solar (no inverter) and like to keep things pretty simple. It's beginning to sound like the ETI installed EMS is a slam dunk on the peace of mind scale.

Surge Protection (Check)
Low Voltage Protection (Check)
Polarity Protection (Check)
Inside (Check)

Being the Google Electrician I really appreciate all of your responses.

[Ron in BC]

Originally Posted by WillyB

Thanks for the info.

I think I understand Reversed Polarity but still wrapping my head around it. I think of it like a one way street. Hot is the start and Neutral is the other side. So if you Reversed them then the traffic is going the wrong way. I think?

Sorry AC is a two way street. DC is a one way street.

Reverse polarity means some nitwit has hooked up the black (hot) wire to the terminal meant for ground. And the white (ground) to the other terminal. Looking at a plug you can see that one prong is smaller than the other. That's the hot wire. Attach it to the other larger terminal and you have a reverse polarity.

This simple plug in tester is an easy way of checking unknown wiring. Ironically it shows this receptacle on the side of my Dad's old table saw reading correctly. I started using this saw when I had to stand on a block of wood to be tall enough. For years every time I used it I'd get a buzz. Dad said something about backwards wiring but didn't know enough to fix it.

Different strokes, different folks. I don't have an A/C or EMS and very rarely ever plug into shore power except in transit in the middle of Winter to use the electric heater.

200 watts of solar is enough to keep us going indefinitely. We're obviously light conservative users, no all the home kitchen appliances for us.

If I have any doubt about the quality of power I just plug in my tester and look for incorrect wiring and at my simple electrical panel for frequency and voltage.

Ron

[cpaharley2008]

Originally Posted by Iowa Dave

Years ago a guy gave me a Boy Scout hatchet. It was in kind of rough shape. I reworked the handle, cleaned up, sharpened and painted and reset the head. And I’ve used it quite a bit over the years. Last week he called and mentioned he’d broken the handle on his old axe using it to chop ice forming nightly in his horse tank. He hated the thought of buying a new one, or fishing the head out of the tank and getting a new handle. Down in the shed, in my axe bucket, an old, used but serviceable double bit. My logging days over, I delivered it to his porch while he was gone. He called and told me an axe elf had visited. That’s friendship and it’s worth more than money to me.
And Rita commended my tiny act of downsizing.
Iowa Dave

In our house "downsizing" is when one loses weight, something we have not done in awhile....... Seems like we eat more the colder it becomes.......yet we do less??

[Vermilye]

Originally Posted by WillyB

Thanks for the info.

I think I understand Reversed Polarity but still wrapping my head around it. I think of it like a one way street. Hot is the start and Neutral is the other side. So if you Reversed them then the traffic is going the wrong way. I think?

We will most definitely have surge protection. The fancy portable seems as much as the ETI installed EMS. Just not sure yet if the portables do all the stuff the ETI one does.

Good thing we still have time to figure things out. Between Colors, Windows, Seating, Stoves/Ovens, to lift or not to lift, Etc. Etc... we see many sleepless nights ahead.

Thanks for the help!

Not quite. AC actually goes both ways, so no one way streets.

If you are not interested, feel free to skip a long winded explanation:

A long, long time ago, either wire in a 120V AC system was hot to ground. Eventually, it was determined that carrying the utilities practice of grounding one of the legs of AC to the consumer would be good. So, at the service entrance to your house one of the two 120V AC wires was connected to the earth (ground).

As electrical usage increased, it made sense to make higher voltages available. Most homes are wired with a single phase, 120V/240V 3 wire service. There are 2 hot legs & a grounded neutral that is a center tap to the transformer that split the single phase 240V pair of hots.

A single voltage system such as out trailers uses a hot, a grounded conductor (neutral) and a ground. Circuit breakers are places in series with the hot wire.

We are now getting to reverse polarity. Sorry it took so long, but without a general idea of how AC gets to us, it would be difficult to explain.

Anyhow, as far as your appliances are concerned, the polarity (which wire is the hot & which is the grounded conductor) makes no difference. Since the direction of current in AC wiring switches back & forth 60 times per second, your air conditioner, toaster or light bulb doesn't care. The physical grounding of the appliance is done through the 3rd non current conducting ground wire.

In a perfect world, reversed polarity would not cause a problem, but if there is a fault, ie a hot wire ends up connected to the frame of your trailer due to a failure of an appliance, etc reverse polarity presents a problem.

If the fault between hot & the trailer frame happens and the frame is properly grounded, and the polarity is correct, the circuit breaker in the hot wire would trip. If you reverse the polarity, the neutral or what should have been the grounded conductor becomes the hot, but the circuit breaker is in the other wire, and won't trip. You might trip the breaker further up the chain (such as the pedestal breaker) if the trailer ground is good, but the breaker(s) in your trailer is now protecting the wrong wire.

If you have a bad ground, no circuit breaker will trip & the trailer frame will be at 120V. The earth is still at ground potential, so a shock hazard exists between anyone touching the trailer metal & standing on the earth. Even a stream of water could cause a shock since non distilled water is a conductor and a fault in the electric heater in the water heater can make the entire water system live.

This points out the importance of a good ground. If you have a fault (normal or reversed polarity) to the trailer frame (and remember, most appliances end up connected to the frame through their ground wire) that draws current below the trip current of the circuit breaker, it won't trip, but the metal in the trailer will still be at 120V potential. All it takes is as little as 50ma - 75ma to kill you, way below the smallest circuit breaker in your trailer.

Again, with normal polarity & a good ground, the breakers trip with a large fault, and most of the current is carried by the ground system for small ones.

[WillyB]

Did you add that panel or is it a standard ETI panel?

[WillyB]

Thank you Jon!

Great explanation!

[Ron in BC]

Originally Posted by WillyB

Did you add that panel or is it a standard ETI panel?

It's just two under $10 gages that I installed in a piece of plastic.

Ron