RV Electrical Safety ("Total Power Protection" Changing Lanes Video)

[howson]

Probably stealing some of GDRV-Emily 's thunder here (you even got a shoutout, Emily!) but here's a link to a video by Changing Lanes that is very applicable to this Technical Forum:

[GDRV-Emily]

howson HAHA!!! Thank you for sharing. I am a little behind on sharing this week

[howson]

..."if" it's going to happen....it's a matter of "when" it's going to happen.

A mea culpa. When I connected to the pedestal at MORryde's facility I didn't connect the power cord to my 315RLTS correctly. When I threw the circuit breaker on the pedestal and checked my EMS' display it read "E2" (Open Ground). I thought the pedestal was bad so I tried another. Same code. I went and checked the camper and voila--found the cord wasn't in right.

Bottom line--I agree with you 100%. An EMS (or "Total Electrical Protection") device is a must-have for those of us that drag our campers from site to site and are susceptible to making mistakes. (I'm at the head of the line!)

[TucsonJim]

Please understand that this video has some misinformation that should be corrected with regards to the Hughes Autoformer. The Autoformer will NOT reduce power in the park for other users. This myth has been perpetuated for years. If you use, or would like to use an Autoformer in lieu of or in addition to an EMS, check out the link from Hughes below.

https://hughesautoformers.com/autofo...-does-it-work/

BTW - here is the surge protection from 50 amp devices:

Progressive Industries - 3580 Joules
Southwire - 3850 Joules
Hughes Autoformer - 4800 Joules

As stated in the video "Low voltage is the number one killer of RV AC compressors". I'd rather have a system that boosts the voltage instead of just shutting it off when it gets too low. When we were at Pony Express RV park in Salt Lake last year, their voltage was running 103 - 105 volts almost all day. The AC would shut down dozens of times an hour when the PI EMS sensed low voltage. The result was that the AC never had time to cool the coach, and the temperature climbed well into the 90's.

[howson]

Please understand that this video has some misinformation that should be corrected with regards to the Hughes Autoformer. The Autoformer will NOT reduce power in the park for other users. This myth has been perpetuated for years. If you use, or would like to use an Autoformer in lieu of or in addition to an EMS, check out the link from Hughes below.

https://hughesautoformers.com/autofo...-does-it-work/

BTW - here is the surge protection from 50 amp devices:

Progressive Industries - 3580 Joules
Southwire - 3850 Joules
Hughes Autoformer - 4800 Joules

As stated in the video "Low voltage is the number one killer of RV AC compressors". I'd rather have a system that boosts the voltage instead of just shutting it off when it gets too low. When we were at Pony Express RV park in Salt Lake last year, their voltage was running 103 - 105 volts almost all day. The AC would shut down dozens of times an hour when the PI EMS sensed low voltage. The result was that the AC never had time to cool the coach, and the temperature climbed well into the 90's.

I'm subscribed to Changing Lanes--do you want me to post on their page with this info or are you going to?

[TucsonJim]

I'm subscribed to Changing Lanes--do you want me to post on their page with this info or are you going to?

I've already done so Howard.


Jim

[OffToHavasu]

Please understand that this video has some misinformation that should be corrected with regards to the Hughes Autoformer. The Autoformer will NOT reduce power in the park for other users. This myth has been perpetuated for years. If you use, or would like to use an Autoformer in lieu of or in addition to an EMS, check out the link from Hughes below.

https://hughesautoformers.com/autofo...-does-it-work/

BTW - here is the surge protection from 50 amp devices:

Progressive Industries - 3580 Joules
Southwire - 3850 Joules
Hughes Autoformer - 4800 Joules

As stated in the video "Low voltage is the number one killer of RV AC compressors". I'd rather have a system that boosts the voltage instead of just shutting it off when it gets too low. When we were at Pony Express RV park in Salt Lake last year, their voltage was running 103 - 105 volts almost all day. The AC would shut down dozens of times an hour when the PI EMS sensed low voltage. The result was that the AC never had time to cool the coach, and the temperature climbed well into the 90's.

I know there are ways to hide it, make it invisible, etc. Just note, per the NEC, devices like the Autoformer are not to be used.

[howson]

...there are discussions going on about "banning" the use of Autoformers....the NEC (National Electric Code) folks are looking at it and considering that path. ...it's enough of an issue that they (NEC) is investigating and Wil likely make a decision at some time in the future because of it.

https://www.rvtravel.com/rv-electric...oltage-report/

Now the inevitable questions about Hughes AutoFormers will start coming in. And while an auto-boost transformer could increase the voltage at a single campsite, it will be stealing even more voltage from the campsites around it. Don’t believe the marketing hype on the Hughes website. A booster transformer can’t restore full wattage (power) to a campsite. It can only restore full voltage by essentially stealing it from other campsite pedestals in the area. That’s why the 2020 version of the National Electrical Code will likely prohibit booster transformers in campgrounds. -Mike Sokol

[OffToHavasu]

https://www.rvtravel.com/rv-electric...oltage-report/

Now the inevitable questions about Hughes AutoFormers will start coming in. And while an auto-boost transformer could increase the voltage at a single campsite, it will be stealing even more voltage from the campsites around it. Don’t believe the marketing hype on the Hughes website. A booster transformer can’t restore full wattage (power) to a campsite. It can only restore full voltage by essentially stealing it from other campsite pedestals in the area. That’s why the 2020 version of the National Electrical Code will likely prohibit booster transformers in campgrounds. -Mike Sokol

It's already in the 2017 NEC:

Part II. Combination Electrical Systems
551.20 Combination Electrical Systems.
(E) Autotransformers. Autotransformers shall not be used.

On edit it's also in the 2011. I'll have to see if I have an older version somewhere.
On edit again. Also in the 2005 NEC.

[TucsonJim]

Interesting info folks. The real issue appears to be in NFPA 1192 which will ban them starting in 2020. Hughes is fighting it, but it appears they lost. It's very upsetting for me to have spent that kind of money for something that can't be used because the RV parks can't or won't upgrade their infrastructure to provide reliable power.

https://rvtailgatelife.com/2019/futu...totransformers

[Cate&Rob]

This does not make sense that a transformer of any kind should be banned. Lets presume that everybody in the park is getting the same 30A at 105 VAC. What you do with your portion downstream of the connection to the post is not going to affect the supply. You could put it through one type of transformer to charge the batteries (reduce the voltage) or through another type of transformer to increase the voltage for the AC, or use it in resistive circuits like area heaters, the toaster or the coffee maker. Why single out and ban one particular device?

Rob

[TucsonJim]

This does not make sense that a transformer of any kind should be banned. Lets presume that everybody in the park is getting the same 30A at 105 VAC. What you do with your portion downstream of the connection to the post is not going to affect the supply. You could put it through one type of transformer to charge the batteries (reduce the voltage) or through another type of transformer to increase the voltage for the AC, or use it in resistive circuits like area heaters, the toaster or the coffee maker. Why single out and ban one particular device?

Rob

Agreed Rob - After reading a little more, it appears that there is a competitor to Hughes which may have input to the regulations. But it all boils down to Ohm's Law. Power = Voltage x Current. If I'm using 3000 watts of power in my rig, and the park's voltage is 105 volts, then I'm pulling 28.6 amps of power. If I'm using that same 3000 watts of power and the pedestal voltage is 118 volts, then my current usage is 25.4 amps.

And the other issue is that if a park has substandard voltage, lots of people have EMS products and they will kick off when that voltage hits 104V. So they all come back on at the same time and all the AC's are starting up at the same time. Now you have a vicious cycle of starts and stops which draw even more current. Maybe EMS systems with auto-shutoffs should be banned?

Jim

[gbkims]

The NEC allows the RV Parks to build their electrical system to meet a minimum electrical load demand.

NFPA NEC 2020

Article 551 - Recreational Vehicles and Recreational Vehicle Parks

551.73 Calculated Load
(A) Basis of Calculations.
...The demand factors set forth in Table 551.73(A) shall be the minimum allowable demand factors that shall be permitted in calculating load for service and feeders.

(B) Demand Factors.
...Informational Note: These demand factors may be inadequate in areas of extreme hot or cold temperature with loaded circuits for heating or air conditioning.

Table 551.73(A) Demand Factors for Site Feeders and Service Entrance Conductors for Park Sites
...Number of Recreational Vehicle Sites: 36+ Demand Factor 41%

[Cate&Rob]

if a park has substandard voltage, lots of people have EMS products and they will kick off when that voltage hits 104V. So they all come back on at the same time and all the AC's are starting up at the same time. Now you have a vicious cycle of starts and stops which draw even more current.

From this perspective, you would think that parks would want lots of trailers to have autoformers, to minimize power surges. You just gotta luv regulations based on politics . . .

Rob

[OffToHavasu]

• The main disadvantage of an autotransformer is that it does not have the primary to secondary winding isolation of a conventional double wound transformer. Then an autotransformer can not safely be used for stepping down higher voltages to much lower voltages suitable for smaller loads.
• If the secondary side winding becomes open-circuited, load current stops flowing through the primary winding stopping the transformer action resulting in the full primary voltage being applied to the secondary terminals.
• If the secondary circuit suffers a short-circuit condition, the resulting primary current would be much larger than an equivalent double wound transformer due to the increased flux linkage damaging the autotransformer.
• Since the neutral connection is common to both the primary and secondary windings, earthing of the secondary winding automatically Earth’s the primary as there is no isolation between the two windings. Double wound transformers are sometimes used to isolate equipment from earth.