Escapees Park bands Autoformers?

[Barbaraok]

As far as co-ops upgrading their electric distribution systems, that's a long and costly process. Probably more than most of the residents who can live with the limitations are willing to spend.

 

In order to get back what they put into the Co-Op, someone has to buy in when they want to leave. If your pool is limited to Escapee members, people who travel and visit your co-op and find deficiences, who then talk about it to other Escapess (via this board, in campground conversations, poor reviews in RV Parks Reviews, etc., how is that going to happen? We've seen this with several parks over the past 10 yrs - either their systems are out of date, or the current members of the co-op are hostile to those traveling through, so we write them off the list. We finally just gave up on the idea of buying into a Co-Op and went in another direction. So the parks lost us. Wonder how many others they have lost and how long they can keep doing so?

[oldjohnt]

Yo Lou Schneider,

 

 

"One factor that hasn't been addressed is the series resistance of the electrical supply."

 

 

RIGHT ON. The no load voltage way out at the end of a long wire run farrrrrrrrrrrr from the distribution transformer is one thing, but place a high current load and all the series I x R voltage drops take place (long wire runs and more connections = more resistance) and you're wayyyyyyyyyyyy down on voltage at your particular pedestal which can cause even more surge current and tax a transformers capacity to deliver V x I power to the RV.

 

As you likely know the generic term "transformer" might include an autotransformer or an isolation transformer and when you consider wasted heat energy PLUS all the possible WRONG ways to wire and configure an alternate energy source and separate or not derived sources and single point grounding and neutral ground bonding to an RV with isolated Neutral and Ground busses ITS NO SURPRISE TO ME THE NEC FROWNS ON THEM AT RV PARKS

 

John T

[Kirk W]

We've seen this with several parks over the past 10 yrs - either their systems are out of date, or the current members of the co-op are hostile to those traveling through, so we write them off the list. We finally just gave up on the idea of buying into a Co-Op and went in another direction. So the parks lost us. Wonder how many others they have lost and how long they can keep doing so?

What you say is true, but most, if not all of the Escapee co-op parks still have a waiting list for lots in them. At one time Evergreen-Coho was dealing with some infrastructure issues and had some of those problems but over time the board changed and money got spent and currently they have 68 names on their waiting list. I believe that Park Sierra is in similar situation, where they had no wait list for a time, but have one again now.

 

Any small community tends to wax and wane on such issues based upon the attitudes of those who happen to be living there at any given moment. There is risk in buying into any such situation whether an RV community or a more conventional stick house community. It is probably more that way with communities of older people since when they begin most everyone there is similar age so they tend to become stagnate once sold out, until the residents age reaches a point where lots begin to change owners. A constant injection of new members is good for these communities, just as is true for internet forums like this one,

[docj]

I found this post in another forum. I'm not qualified to assess if the arguments cited are valid, but they provide an entirely different perspective on the issue we've been discussing. The problem with discussing topics on forums such as this in the absence of real data is that people often convince themselves of an answer without any way to verify that their reasoning is correct. In the example I'm posting the rationale for the NEC prohibition on autotransformers is entirely different from what we've been assuming. It leads me to think that without an authoritative source who can interpret the real intent of the NEC none of us are going to really know why the prohibition exists and how it should be interpreted.

 

"You (and others in this thread) are incorrectly supposing that the code's proscription against autotransformers is related to "buck/boost" transformers such as the Hughes model -- it is not.

Note that buck/boost transformers do not need to be made with an autotransformer -- they can be (and sometimes are) made from a standard isolating transformer instead. Likewise, many autotransformers are used simply to convert voltage, rather than in variable buck/boost applications, the most common being to derive, for example, 120vac power for a device from, say, a 277-volt source because that was what was available. I blame Hughes for this confusion, since their marketing materials tend to associate the two technologies, when in fact there is no association whatsoever (except in their own product).

The reason the code forbids them in RVs has to do with safety issues related to the way an autotransformer works. In particular, certain kinds of fault conditions can cause the full input voltage to be applied to the output, which is hazardous if the transformer is being used, for example, to convert 240vac to 120vac. These devices also have different ground fault considerations. For this reason the code forbids them in many places (not just RVs). For example, they may not be used in most wet location applications.

Note that the code was not looking at the type of buck-boost devices you are talking about, but rather autotransformers in general. Putting one in-line in a properly grounded shore service does not present the same safety issues as having one built-in between the coach's main panel and an appliance or receptacle.

All that said, the code proscription means that an autotransformer can not be built into an RV, even wired ahead of the main panel at the shore input. So if a manufacturer wanted to include a voltage-boosting system (which is allowed under the code), it simply needs to be the type that uses a regular, isolating-type transformer. Neither does the code prohibit use of a free-standing unit in-line in the shore connection, such as the Hughes."

[Kirk W]

I found this post in another forum. I'm not qualified to assess if the arguments cited are valid, but they provide an entirely different perspective on the issue we've been discussing.

It makes a lot of sense to me, but as a lowly tech, I'll leave the debate to our resident engineers.

[lasttruck]

 

In order to get back what they put into the Co-Op, someone has to buy in when they want to leave. If your pool is limited to Escapee members, people who travel and visit your co-op and find deficiences, who then talk about it to other Escapess (via this board, in campground conversations, poor reviews in RV Parks Reviews, etc., how is that going to happen? We've seen this with several parks over the past 10 yrs - either their systems are out of date, or the current members of the co-op are hostile to those traveling through, so we write them off the list. We finally just gave up on the idea of buying into a Co-Op and went in another direction. So the parks lost us. Wonder how many others they have lost and how long they can keep doing so?

Quite true. Co-ops are not for everybody. Some purchase a membership expecting to contribute nothing more than their presence and annual maintenance fees while others volunteer where they can to make "their" park the best that it can be.

 

We have also noticed that a stagnant population can lead to apathy and failure to grow. I will speak only of Evergreen Coho in Chimacum, as I do not have much information about the other SKP co-ops.

 

Here at Evergreen, keeping the annual fees low was the norm. Any attempts to increase the fees was met with strong opposition. Of course, that led deferred maintenance and postponing upgrades.

 

The last few years has seen quite a change. Several members left the park after the annual fees were raised to take care of and upgrade the aging septic systems. That allowed for an infusion of younger members who saw the need to spend money to keep the park in good shape and upgrade as needed.

 

The parks finances are very solvent. There currently is a good fund for any needed septic repairs along with annual septic system inspections. WAVE broadband, TV and phone service was brought into the park this summer (after years of opposition) and a pair of 110 mbps lines have been installed for a park wide Wi-Fi system (currently being tweaked before opening for visitors to use).

 

Professional contractors were brought in to inspect and service the electrical system. The park is working with the local PUD making plans to add another high voltage line into the park (all underground). This line would service the back portion of the park, allowing more capacity for the rental areas and park shops for future upgrades.

 

It does take time and money.

 

In 2014, the Board of Directors set the annual fee at near $3000 ($800 turned into an assessment at the annual meeting), which I understand is quite a bit more than the budget committee recommended. That led to a large number of memberships being turned in and empty lots for several months. It was a hard decision for that BOD, but a necessary one.

 

In 2015, the BOD set the annual fee just under $2000. A lot had been accomplished, but after a lot of the work that was needed, reserves needed to be replenished. By the time of the annual meeting in August (that morning), the last empty lot/membership had been claimed. The park was full again.

 

In 2016, the budget committee made a very good budget recommendation to the BOD. It covered everything that needed covering and bolstered the replacement/contingency funds as well. The BOD was ready to accept the recommended budget at the well attended meeting when the membership, almost unanimously, requested that the annual maintenance fee be raised.

 

The reasoning was that upgrades to the electrical system needed to be made along with some other improvements. After discussion, the BOD set the annual maintenance fee to be the same as the previous year.

 

Talk about a change for the better.

[SIBERNUT]

OK, I admit I am electrically challenged. Is there any difference between Autoformers (like Hughes) and AutoTRANSformers ?

[Dutch_12078]

OK, I admit I am electrically challenged. Is there any difference between Autoformers (like Hughes) and AutoTRANSformers ?

 

Hughes lists their "Autoformer" as an "autotransformer" with U.L.

 

Specifications

• 50 Amp – double phase, 12,000 Watts capacity
• Fully automatic 10% boost when needed (95v-115v)
• Park power diagnostic light
• Boost indicator lights for each line (2)
• Spike and surge protection
• U.L. listed Autotransformer
• Size: 12”H x 8 ½“ W x 5½” D
• Weight: 35 Lbs.
• Two-year limited warranty
• Made in U.S.A.

https://hughesautoformers.com/product/50-amp-12000-watt/

[oldjohnt]

HEY DOCj, Good technical info, thanks for posting.............

 

That's EXACTLY what I was talking about above and feared when I spoke of (in addition to the waste of energy issues) the potential safety problems associated with Single Point Grounding and Neutral Ground Bonding and the fact the RV panel (unlike a home panel) has an isolated Neutral and Ground Buss. Also an autotransformer is DIFFERENT then an isolation transformer and is DIFFERENT then a transformer which uses tap changing as a means to compensate for low voltages. Since the Grounding and Bonding and Transfer Switch methods can vary between different types of transformers and the same is true depending on if the alternate energy source is configured as a Separately Derived Source or NOT,

 

AS I POSTED ABOVE

 

"ITS NO SURPRISE TO ME THE NEC FROWNS ON THEM AT RV PARKS"

 

Thanks again, I enjoy this techy sparky chat at the risk or boring others lol

 

Best wishes yall and again even if we don't understand an NEC prohibition, that don't mean we shouldn't take it seriously, as it could save our life!!!!!!!!!!!!!!!

 

John T Tooooooo longggggggggggg retired and rusty on all this so no warranty, consult the NEC and take their word for it not mine!!!!

[Lou Schneider]

OK, I admit I am electrically challenged. Is there any difference between Autoformers (like Hughes) and AutoTRANSformers ?

 

Hughes Autoformer is a trademarked name for their version of an automatically adjusting autotransformer. So the Autoformer is an autotransformer.

 

A conventional transformer uses separate windings for the input and output. An autotransformer shares one winding between both. Taps on the winding let you boost or cut the output voltage compared to the input.

 

The problem with using autotransformers in an electrical distribution system is the limited isolation between the input and output. One end of the winding is connected to both the incoming and outgoing power so there's a straight-through connection between them. The other leg passes through part of the winding between the input and output.

 

In a 120 volt circuit, the common end of the autotransformer will be connected to the neutral line. Usually about half of the voltage loss in the circuit will be in the neutral wire returning to the neutral/ground bonding point. The neutral is supposed to stay at 0 volts, but the neutral to ground bond is WAY back at the park's main panel so you can lose voltage along the return line.

 

Any voltage loss along the neutral line will make the far end RISE above ground. If you're losing 20 volts along the circuit, the neutral at your site can be 10 volts above ground.

 

If you design a system with several autotransformers in a row, you can compensate for a very large voltage drop by the time you get to the far end of the line. However, there is no compensation for the neutral rise and it can rise into possibly dangerous territory.

 

Transformers (not autotransformers) use separate windings for the input and output. This isolates the two and lets the system designer ground the neutral at the transformer's output, breaking the long and potentially dangerous run all the way back to the distribution source.

 

Note that in practical terms, the neutral voltage rise is only significant when you're using an autotransformer to compensate for a large voltage drop, or if you're using multiple autotransformers stacked one after the other in a long distribution system. It isn't a problem when you're using one autotransformer to feed a short cord into an individual RV.

[oldjohnt]

Yo Lou Schneider,

 

ANOTHER EXCELLENT INFORMATIVE POST, to your statement (you and Docj and Dutch and others are fun to chat with concerning this near and dear to me issue)

 

"Transformers (not autotransformers) use separate windings for the input and output. This isolates the two and lets the system designer ground the neutral at the transformer's output, breaking the long and potentially dangerous run all the way back to the distribution source."

 

 

I WILL ADD A BIT MORE TECHNICAL INFORMATION (I'm sure you already know) which may help others understand the potential dangers concerning Single Point Grounding,,,,,,,,,Neutral Ground Bonding,,,,,,,,,,,,,,and Neutral Grounding.

 

 

If you were to place a full isolation transformer in between the RV pedestal and your RV that could create a "Separately Derived Source" IE what the NEC may refer to as an "Alternative Energy Source", SO YOU NEED CORRECT NEUTRAL GROUND BONDING PLUSSSSSSSSSSSS CONNECTION OF THE NEUTRAL TO A PROPER GROUNDING ELECTODE. The park already has a Neutral Ground Bond (none exists in an RV panel) and their Neutral is already connected to a Grounding Electrode (such a "made electrode" created by a rod driven into mother earth) but when you insert that type of transformer ALL MUST BE RE-ESTABLISHED unless you're going to operate on a non grounded "floating" system.

 

Now if a park owner or a non electrician or non tech or non engineer or anyone who wasn't aware of all the danger and safety issues were to insert such a transformer and NOT create the proper bonds and grounding YOU COULD POTENTIALLY CREATE A HAZARDOUS SITUATION AND VIOLATE THE NEC !!!!!!

 

I will say it again and I understand why " "ITS NO SURPRISE TO ME THE NEC FROWNS ON THEM AT RV PARKS"

 

Very fun and informative and hopefully helpful thread

 

Best wishes and God Bless yall, keep safe

 

John T

[SIBERNUT]

"It isn't a problem when you're using one autotransformer to feed a short cord into an individual RV."

There's my answer, THANK YOU Lou.

Now- is there a way to make it safer, such as a stake with a grounding wire when in a CG ? I do that when the rig is at home, because there seems to be a discharge when I touch the rig. This is using a regular 3 wire drop cord with a ground in it, 110V.

[Kirk W]

Note that in practical terms, the neutral voltage rise is only significant when you're using an autotransformer to compensate for a large voltage drop, or if you're using multiple autotransformers stacked one after the other in a long distribution system. It isn't a problem when you're using one autotransformer to feed a short cord into an individual RV.

Which is the point of this entire thread. I very much doubt that the authors of the electrical codes were even aware of products like the Hughes Autoformer, the TRC voltage booster, or any of the smaller players in the RV accessory market in mind. What matters for the typical RV owner is that there really is no actual problem created in using one of them, if used properly. For us, I never carried one and really never had significant need for one as we just didn't stay in parks with poor power and rather than a booster system, we used a combination surge protector/power monitor to protect the RV systems and we moved elsewhere when power was insufficient. But from what we have observed those really can be important to people who spend a lot of time in Mexico or other places where low voltage supplies are common. They do work and they don't "steal" power from others.

[Dutch_12078]

It appears the NFPA added the autotransformer prohibition in either the 1990 or 1993 edition. It's not there in the 1987 edition, and I do not have a 1990 edition available, but it is included in the 1993 and later editions. I have no idea what prompted the inclusion...

 

Oh, and if anyone's interested, the very first NEC, the 1897 edition, is available online here. All 58 pages...

[oldjohnt]

Yo Kirk, in response to your remark

 

" I very much doubt that the authors of the electrical codes were even aware of products like the Hughes Autoformer, the TRC voltage booster, or any of the smaller players in the RV accessory market in mind"

 

I must with all due respect and graciously beg to differ. Based on my NEC Seminars and tri yearly update courses over many years and based on conversations with and attending classes taught by TRUE WORLD CLASS RECOGNIZED ELECTRICAL EXPERTS who served on the boards of the NEC, its my pure "opinion" they were aware of any so affected electrical devices when any "relevant" regulations concerning them were published. Those who serve on NEC boards and committees are in my opinion some of the most knowledgeable finest electricians and technicians and engineers out there and YES they can and have been wrong, they are NOT infallible for darn sure.

 

ALL I'm saying is if the NEC issued a rule regarding the use or non use of any sort of transformer or autotransformer its my "opinion" maybe right maybe wrong, you may be 100% correct, THEY WERE AWARE OF SUCH AFFECTED PRODUCTS AND WHY THE RULE WAS NECESSARY AS RELATED TO SUCH PRODUCTS. Its my opinion and observation when they make a rule about something, its NOT unresearched and is based on experience and sound reasons BUTTTTTTTTTTT that's just my opinion, observation and experience NO WARRANTY LOL, for all I know they weren't aware of those products?????????? as you mentioned. If they banned use of a certain product, you can bet they were aware of it and how it operated. Of course, the NEC is only updated every three years and new products can come on the market, but when the new code comes out and deals with such products Id bet they are aware of and research them prior to issuing some sort of ban like at an RV park.

 

I NEVER blindly followed the NEC but once I studied and researched and understood the reasons behind any of their rules I found them to be safe and sound and correct and saw how they might save a life or prevent a fire

 

HOWEVER your opinion which I highly respect and admire, may be 100% accurate and mine wrong as rain lol. We can respectfully agree to disagree, it would be a boring world if we all shared the same opinions now wouldnt it lol

 

Take care best wishes n God Bless. I sure hope I get to visit you sometime when I'm in Texas. Thanks for all the help and expertise you have provided myself and others on here, I sure appreciate it.

 

John T

[oldjohnt]

SIBERNUT and others just FYI

 

In the event you drive a rod into the earth and if a wire attached to it creates a spark when touched to an electrical appliance:

 

1) There exists a potential voltage difference between earth and the appliance at that location.

 

2) HOWEVER THAT MAY SIMPLY BE THE (LOW energy) RESULT OF CAPACITANCE OR INDUCTANCE created by current carrying neutral and hot and ground wires being ran in parallel with each other.

 

3) Such can cause the voltage say on the equipment ground conductor (perhaps bonded to outer metallic conductive case/frame of an appliance) to be elevated above mother earth at that location so attaching to an earth ground rod dissipates that energy and you can get a spark.

 

IMPORTANT SAFETY HOWEVER using ONLY a driven ground rod can not substitute for the safety created proper Equipment GroundING conductor established at the Neutral Ground Bond location. The safety Equipment GroundING (bare/green) Conductor is to create a direct dedicated low impedance FAULT CURRENT return path while the GrounDED Conductor (Neutral) is to carry normal return current.

 

If you relied on ONLY a driven rod to return fault current, subject to the mineral and water content and distance, the resistance is far too great and current far too low to trip the protective device AND YOU COULD DIE since it only takes maybe 30 to 60 milliamps of current around your heart to cause fibrillation

 

PLEASE DONT THINK DRIVING A GROUND ROD IS A CURE ALL AND 100% GUARANTEED LIFE SAVER NOR SUBSTITUTES AS A PROPER EQUIPMENT GROUNDING CONDUCTOR FOR RETURNING FAULT CURRENT. The Neutral is bonded to a proper Grounding Electrode to protect against surges and lightning and to keep the grid at a common low voltage reference IE mother earth.

 

NOTE there can be other reasons why the potential of a device or appliance is higher then mother earth, the capacitance and inductance is ONLY one reason. If its high and has more energy, THAT CAN BE A FAR MORE DANGEROUS SITUATION I cant cover every possible situation here.

 

Hope this helps, such info can be life saving, I apologize if were boring the others

 

John T Longgggggggg retired Electrical Power Distribution Design Engineer and RUSTY so no warranty, consult the NEC and take their word for this NOT MINE

[oldjohnt]

MORE FYI for Sibernut and others

 

In response to how you might safely "ground" a transformer or a distribution system etc:

 

1) If a "Separately Derived" or "Alternative Energy Source" is created, say by your own traditional transformer or an isolation transformer or an Inverter or Standby Generator.............

 

2) if you want to use it as a non floating "grounded" power source

 

3) You: a) Bond the Neutral to all readily available "Grounding Electrodes" which could be a "Made" Grounding Electrode such as an earth driven ground rod and/or structural building steel or conductive foundation iron or conductive buried utility pipes etc; BOND the Neutral Buss to the Equipment Ground Buss. Obviously you cant drive a ground rod connect to it and drive off lol the Case/Frame of a Generator can be used as a substitute. Some small gennys have a floating Neutral while others and larger have a Neutral to Ground bond. BUT DONT FORGET THERE IS ONLY TO BE ONE NEUTRAL GROUND BOND IE Single Point Grounding

 

I sincerely apologize for being too techy or long winded but this is the only way I (Engineer and Attorney) know to try and help and explain this fairly complicated subject HEY IM TRYING MY BEST TO HELP AND KEEP YALL SAFE

 

Consult the NEC take their word NOT my old rusty recollections lol

 

John T