NOTE: This post is something I wrote back in May 2015, and was published on the Escapees HDT Forum. Here it is with a few minor updates. Still my most-used electronic driving aid!
After adding a Volvo hood-mounted mirror, I still wasn’t quite happy with how well I could see my front right corner. I feel like I have really good coverage down the side with the normal and wide angle mirrors, the over-the-window mirror, and now the hood mirror.
This afternoon, I added a camera to the mirror, facing down, so I can finally see how close I really am. Total project cost was about $35–slightly more for the Voyager connector I needed ($18) than for the camera ($17). Here’s how I went about it (with a few pictures).
This short write-up about making custom step covers goes back to something I did years ago on my first RV, and quickly duplicated after getting my current one.
Inevitably, dirt gets tracked in. In a campsite with grass, a paved site or patio, or good gravel, it’s not too bad. But sandy and/or muddy areas become a problem. I can take off my shoes, Milo wears his “shoes” all the time.
Off-the-shelf RV step rugs aren’t often the exact side you need, and tape/velcro doesn’t work too well to keep them in place, especially if you have carpeted steps.
Making your own Step Covers
Here’s what you need (everything can be purchased at Wal-Mart, Menard’s, etc.):
There are lots of rugs that would work for this, but at the very least it needs to be one that you can cut to size with a knife or scissors, preferably with nothing around the edges. Here’s an example:
The first order of business is cutting the rug into pieces to fit the steps. That should be pretty self-explanatory.
Next, anchor two of the male half of the snaps with a screw near the front outside edges of the stair tread:
Lay the rug on the stair tread, and mark the location of the snaps. Cut a small hole for the female side of the snap, and use a hammer and the rivet tool included with the snaps to set it in place. That’s it!
When I first started RVing, a little over 11 years ago, I bought a new toaster. It wasn’t fancy–a two slice Toastmaster bought for about $20. It worked fairly well, from 2006 until 2013. But it failed, and the circuit board with the timer wasn’t repairable. It was a throwaway appliance, made in China.
That failure was disappointing. I remember an old toaster in my grandmother’s kitchen that they got not long after they were married. It had a battle scar from falling off of the top of the curved refrigerator where it lived when not in use. But it was regularly in use for more than half a century–that kitchen cranked out some of the best breakfasts on the planet.
The water misters can make the air conditioner perform better, but does it make sense to use them? Of course, if you’re in a campground with unmetered water and electricity, there are no immediate savings other than comfort.
Electricity is one of the bigger costs in operating an RV park though, so we all pay in some form or another. The park doesn’t get it for free, and the cost is ultimately passed on to the consumer, so everything we can do to reduce our own usage benefits the community at large.
Calculating Air Conditioner Costs
If we make a few assumptions about air conditioner usage, we can estimate the cost of running one for an hour.
For now, let’s take 12 amps as the average load running at 120VAC, and assume a power factor of one. Running the air conditioner one hour consumes 1.44kWh, and a national average residential electricity price of $0.129/kWh gives us a cost of about $0.19 per hour. If the air conditioner runs about 1/4 of the time through the summer, it costs about $33/month to run.
Now let’s consider the scenario using the misters. They reduce the power needed to run the air conditioner by about 10% in my testing, or about $0.02 per hour. But if the air conditioner was previously able to keep up, it will also run less. How much is heavily dependent on the weather, but it could easily be a 25% reduction. That’s over $10 per month, per air conditioner.
But let’s also consider the water usage. If we set it up so the misters only operate when the air conditioner is on, and that we use 0.5gal/h of water, we’d use 3 gallons a day. At the national average price of water, that’s less than half a cent–a negligible amount.
So far, it looks like the misters make sense as far as utility costs. The campground benefits (in most cases) from your using them. What if we’re not grid-connected?
Misting While Boondocking
Here’s where it gets more complicated. Most RVers probably only run air conditioners with their generators running when they don’t have hookups. With a limited water supply, you’re particularly conscious of its use, but you may also want to cool the RV quickly after a day away from it.
Let’s look at the previous math slightly differently. Instead of $0.129/kWh, let’s assume we have a generator that uses 0.5gal/h of diesel at idle, and 1.0gal/h with both air conditioners running. If we only consider running the generator with both air conditioners on, each one is using 0.5gal/h. At about $3/gal for diesel, that’s $1.50/h.
If we’re operating the misters effectively enough to reduce runtime by 25%, we reduce the hourly cost from $1.50 to $1.13. That’s $0.38/hour. Looking just at that part of the equation, the misters can pay for themselves really quickly. The savings would pay for the misters in a couple of weeks running 2 air conditioners for 3 hours a day.
But we’re using water from our fresh water tanks, which has a much higher cost, especially in terms of convenience, than a municipal or campground supply. If it’s 3 gallons a day, in the same two weeks we’ve used 42 gallons each of water and diesel. You quickly arrive at a situation where the answer is it depends. In my case, if the tanks were all full at the start, neither one is limiting. Staying longer than two weeks, fuel and holding tanks would become the limiting factor before fresh water. I’d run the misters. How about you?
Next time I post on this subject, I’ll cover setting it up to run efficiently. It’ll be triggered by the air conditioner’s compressor running, so the nozzles don’t run when the air conditioner doesn’t.
Last fall, I wrote about installing a PC power supply to power the remaining 12V DC loads in my RV, but that’s getting replaced with a DC-DC converter. The power supply did the job it was supposed to, without fail. But there are a few drawbacks with it:
The power supply converts AC power from the inverter to 12V DC. That means the inverter is on, and there’s an extra conversion that wastes energy.
Under load, the 12V output from the power supply is lower than I’d like. At the source, it drops to about 11V, and my rig’s 12V wiring is mediocre at best. Vent fans, water pumps, etc. all run a little slow.
The power supply doesn’t respond well to sudden load increases. This is most evident with the stereo system.
One of those age-old questions of seasoned RVers–not necessarily old ones–is what kinds of plates and other dishes to travel with. I can’t count how many times someone has asked how I pack glass dishes, and I’ve always had a simple answer: I don’t. They just sit in the cabinet where they always do, with nothing in between them.
Just about every RVer has a few power adapters, often referred to as “dogbones,” to make sure that they can connect to whatever power is available to them–this post will go over which power adapter types are safe to use, and which ones you might want to carry.
The job of a circuit breaker or fuse is to protect the downstream wiring from overloading and short circuits. Any wire configuration has a current rating, and a circuit breaker typically protects that wire.
Keeping that in mind, when we adapt an RV with a 50-amp plug (NEMA 14-50P) to either a 30-amp or 15-amp receptacle, the circuit breaker at the source will shut off power the wire’s limit is reached. At worst, under one of these configurations, we experience a nuisance pedestal breaker trip:
50-amp RV cord plugged into 30-amp, 20-amp, or 15-amp receptacle
30-amp RV cord plugged into 20-amp or 15-amp receptacle
For any of these configurations, you can find a UL-listed power adapter, and operate your RV safely.
But the other way doesn’t work. Let’s say you have something you want to power with a normal 15-amp plug. That includes a patio light, a heated hose, space heater or a string of flamingo awning lights. Now suppose you don’t have a 15-amp receptacle on the pedestal, or that you have something else plugged in.
Can you adapt down from a 50-amp or 30-amp receptacle on the pedestal to one for your 15-amp appliance? NO. If there was a problem with the appliance, or its cord, you could easily melt it before the breaker is overloaded enough to trip.
Note that in any of these situations, and even when plugging your RV directly into a pedestal, a receptacle in poor condition is still a hazard. A loose connection can easily generate enough heat to melt your plug or start a fire without tripping a breaker. If a plug goes in with little resistance, the receptacle probably needs replaced.
Power Adapters that are Safe to Use
All of these power adapters will have a smaller, lower amperage plug (male blades) on one end, and a larger/higher-amperage receptacle (female terminals). Look for UL-listed versions of these adapters, preferably with rigid grab handles.
50-amp RV plugged into 30-amp source
Power adapter has 50-amp female receptacle (NEMA 14-50R) and 30-amp male plug (NEMA TT-30P)
These adapters allow for the connection of a smaller cord to a larger source. The cord in this situation could be overloaded without a breaker tripping, which is a safety hazard. These devices cannot be UL-listed.
30-amp RV plugged into 50-amp source
Power adapter has 30-amp female receptacle (NEMA TT-30R) and 50-amp male plug (NEMA 14-50R) DO NOT USE!
Any combination of 15-amp and 30-amp receptacles plugged into 50-amp source
Power adapter shown has 15-amp female receptacle (NEMA 5-15R) and 30-amp female receptacle (NEMA TT-30R) that are split from a 50-amp (NEMA 14-50P) plug. If you look closely, the handle for unplugging is a thin rubber strap that hooks on to the sides–that style isn’t very easy to unplug, and they’ll break, usually long before the plug itself needs retired. DO NOT USE!
Differences between RV Plugs and Common Household Plugs
Perhaps the most confused RV plug is the 30-amp TT-30, which looks very similar to the common 3-wire clothes dryer plug (10-30) which was installed in homes built prior to 1994. The two plugs are physically different in the center pin, but more importantly, they’re wired differently. The dryer plug supplies 240V, with a ground-neutral bond. This bonding means that the ground–which is designed to be a safety feature–is also current-carrying, which negates that function under certain conditions. The National Electric Code prohibited that practice in new home construction beginning in 1994, and a 4-wire plug has been used since then.
If having an electrician install a 30-amp service for an RV, make sure that it’s a TT-30 configuration, and that it’s properly wired to supply 120V with separate ground and neutral.
Which brings us to another plug, the RV 50-amp plug, which is a NEMA 14-50. This plug is commonly found on electric ranges, and is similar to–but different from–the typical dryer, which uses a NEMA 14-30. The 30-amp dryer plug has an L-shaped neutral, whereas the 50-amp RV plug has a straight blade. While not common, it would be safe to plug a 50-amp RV into a 30-amp 4-wire dryer receptacle, but not a 30-amp RV into a 50-amp range receptacle.
Is there a way to plug a 30-amp RV into a 50-amp pedestal?
Yes, but it’s not a product that you can just go out and buy. Do do it safely, you’d need a short cord sized for 50-amp service into a subpanel with a 30-amp breaker. If enough of you are interested, we might build one up to show the process.
Ok. Enough already! I’m a new RVer–what power adapter should I carry with me?
Each of these adapters have a rigid, molded grab handle, and have the plug at the proper orientation so that the cord and plug aren’t strained when hanging. Identify which type of RV you have based on the plug images below.
If you have a 50-amp RV, it should have a plug like this:
In that case, you can plug in anywhere (50-amp, 30-amp, and 15-amp receptacles) with these two adapters:
It’s that time of year again–temperatures are rising and the non-fulltimers are out in force. Depending on where you’re camping, that may mean managing your power use on a limited hook-up, listening to the air conditioner run non-stop, and possibly still being hot inside in the afternoon sun. We can improve on that with a few misters.
At first glance, you might think I’m about to talk about swamp coolers, solar shades, or misters on the patio. Not quite…