TurnThePage wrote:
I keep a Kill-a-Watt plugged into a easily visible outlet and monitor it quite a bit when I initially plug in and especially after firing up the A/C. It's saved my bacon more than once. Low voltage seems to be fairly common at the mom & pop camp grounds around here.
That's what we have. I can look over right now and see it...122.3volts. It just goes into a regular household style outlet. It uses no power to speak of but gives a constant feedback.
What you have to remember is 120v power is a "nominal" rating. In reality, the voltage will vary and there are limits that are considered acceptable (I believe it's +-10%) and device manufacturers are generally expected to make devices that are fine within those limits.
High voltage is generally not an issue. In theory it can be but it's not a common problem as it costs more to put in a park electrical system that provide too much voltage.
Low voltage is fairly common particularly at older or poorly designed parks. Often they were built for small trailers with small electrical demand. Newer larger RVs often have 2-3 air/con units and much higher electrical demands. As you keep adding loads to a circuit, it has the effect of dragging the voltage down. On a hot summer weekend when the park is full and everyone's air/con is running flat out, a weak campground electrical system can have the voltage drug down to the point where you risk damage. Motors, in particular run hotter the lower the voltage...to low and they can burn up.
I don't like to see below 110v but if it gets below 108v, I break out the generator. Some people will tell you you can go as low as 104v but not worth it to me.
An alternate solution is a transformer to boost voltage (often referred to as an autoformer). We have one and it helps quite a bit.
- If you have decent voltage, it provides a very small 2% voltage boost (why we are slightly over 120v right now).
- If the incoming voltage drops below a predetermined level, it switches to a higher boost (10% I believe on ours). So if the pedestal has 104v, it will boost it up to 114.4v, which eliminates the concern. Even with this, we have had the voltage in the trailer drop below 108v, so it's not a cure all.
One issue with an autoformer, to boost the voltage, it draws more amps at the pedestal, so if you are using close to the 30amp limit, it may trigger the breaker.
A key formula to remember Watts = Volts * Amps. Electric motors generally pull the same wattage, so if the volts go down, the amps must go up to compensate. Items like a toaster draw a steady amperage, so if the voltage goes down, they just don't get as hot.
It's really hot days at busy parks where the problem is most common but always good to at least do a quick check when plugging in.
