Just wondering what to purchase to prevent over voltage, ie; in excess of 130 volt. I am not talking of a surge protector, but something that won't allow more than say, 124 or 128 max voltage to get in the coach. We have been at seveal places where the voltage is just to high, 129-133 volts. The built in protector works in the coack, but would rather have something that would Limit the incoming voltage instead of poping the built in equipment on the coach repeatedly. Also where can something such as this be purchased. Thanx.......JD
I think what you might be looking for is a Progressive Industries product. Their permanently mounted 50 A unit will not allow more than the set upper voltage limit into the coach. If it sees more than that limit it shuts off the electricity inside the coach. I don't have one (need to get one), so I can't tell you exactly what that upper limit point is. There are other devices that can raise or lower voltage somewhat, so maybe that is what you are looking for. I would think that the ideal device would be a combination of the two - the PI unit tells the other machine how much to raise or lower the voltage to get it in specs.
That is what we use - the HW50C model. IIRC the upper limit is 132 Vac. It has protected our coach several times from high voltage that occurred during stays at campgrounds (we do have the OEM high/low in our transfer switch, but the Progressive unit responded quicker to a sudden bad situation).
Unit with remote display (what we have, and we have 2 displays with a switch box, one display in the utility bay, one inside the coach near the Power Line Monitor):
http://www.progressiveindustries.net/ems_hw50c.htm (http://www.progressiveindustries.net/ems_hw50c.htm)
Unit with built-in display (cheaper, but you have to go look at it for info):
EMS-LCHW50C (http://www.progressiveindustries.net/ems_lchw50.htm)
Portable unit with built-in display (more expensive, but doesn't have to be wired in. You do have to remember to use it, and it can be challenging to figure out how to secure it from theft if that's a concern for you):
EMS-PT50C (http://www.progressiveindustries.net/ems_pt50c.htm)
I looked up the item listed,but not what I am looking for. I am hoping to find a limiting device that will somehow keep the flow of electricity on but limit it to acceptable levels when it does get to high.
Ah, gotcha. I'm not aware of such a device (doesn't mean there isn't one). Know of "boosting" ones (Hughes autoformer) but not something that regulates/variably controls on the high end (especially since that could be the result of a poor neutral on the supply side - not something readily handled at the receiving end of things).
As I recall, the Hughes Autoformer will either increase or reduce the voltage slightly according to need.
They do vary the amount of boost (by limiting current), but they don't do the opposite.
Hughes - Hughes (http://www.hughesautoformers.com/index.php?option=com_content&view=article&id=34&Itemid=157)
A concern with higher-than-normal voltage is that there's a good possibility of a safety hazard causing the problem.
ETA some info here RV Electric (http://www.myrv.us/electric/) click on "Open Neutral" on the left menu list
The need to reduce high AC voltage and increase low AC voltage is a common item in the utility business. It is called a Buck / Boost transformer and there are manual ones where we pick the transformer windings, or automatic (autoformer) where a circuit board monitors the incoming voltage and then chooses the correct transformer windings.
Popular RV autoformers are marketed to increase only, so they are Boost transformers. We own a Hughes 50-amp Autoformer, but have never opened case so we don't know what is inside.
Here is a write-up that explains how these transformers work:
Autoformer Usage (http://www.beamalarm.com/Documents/autoformer_usage.html)
Thanks to all for the timely reply, I have now alot of food for thought. Thank You all..............JD
Industry standard is plus/minu 10%. 120V nominal plus 10% = 132. Realistically, I wouldn't worry much as long as voltage remains below 140. I'd rather have higher voltage than low volage.
Also that readout by the prosine is not accurate and can vary quite a bit too.
Did the same on my Progressive surge protector. The two blue pots with micro screws located on top of circuit board adjust each leg individually. They had about a 10% error according to Mr. Fluke.
RE: Did the same on my Progressive surge protector. The two blue pots with micro screws located on top of circuit board adjust each leg individually. They had about a 10% error according to Mr. Fluke.
Progressive Industries EMS does not use RMS calculation, like Mr. Fluke.
I do believe US mains voltage is typically stated as RMS, not peak or peak to peak. If the Progressive surge protector was showing peak for 125V mains power, it would be showing around 170 volts. As it was, 120 V on the Fluke meter was showing up as 132 V on the Progressive readout, it was tripping on over voltage frequently. Trimming the pots cured this. Hopefully I have not rendered the device inoperable by "fixing" it!
It doesn't matter on pure sin wave AC power.
It DOES matter when measuring chopped power like from an inverter.
RE: If the Progressive surge protector was showing peak for 125V mains power, it would be showing around 170 volts
When a consumer meter does not use RMS for their AC metering voltage calculation, they use an averaging method to display voltage, not peak to peak.
But the result is that same number on a relatively true sine wave.
Agree....so this discussion is moot.
I just installed an ECOWISE voltage regulator as my "surge guard" was leaving me without power during most nights and a few days. Not nice running the generator in the campground. The power is very high here, 132.8 etc Mazatlan Mexico. The thing cost almost 7000 pesos to buy and install and of course there are no RV plugs! Had to chop a spare 30 to 50 amp dog bone.