Low Tech RVing
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Wednesday, July 25, 2007

Don't Become a Carbon Monoxide Victim

Nearly every new home built in the US has them: Carbon monoxide detectors. These little units can save your life. Carbon monoxide (CO) is a colorless, odorless, tasteless, and often deadly gas, the byproduct incomplete combustion. The combustion source in an RV could be anything from in improperly operating furnace, water heater, oven, generator, or any other device that burns fossil fuels. Small amounts of CO can make you sick--in fact it’s the leading cause of accidental poisoning in the US, with almost 10,000 cases heading into ERs every year. Larger amounts can make you dead: Roughly 200 Americans a year join that statistical tragedy.

The symptoms of CO poisoning include headaches, nausea, dizziness, fatigue, shortness of breath, and two real bad ones: Unconsciousness followed by death. Carbon monoxide is a tricky thing: A little bit of CO over a long time can do harm you, or a lot over a short period of time can do the same. Since there are plenty of devices in an RV that could produce carbon monoxide, it’s good for RVers to know the symptoms of CO poisoning. But it’s much better to have a CO detector warn you before you get any of the symptoms.

All new RVs come from the plant with a CO detector, but hang on. These devices have a limited "shelf life." After five years from manufacture, you detector needs to be replaced. The hard part is, CO detectors for RVs have to meet special requirements--after all they're exposed to a wide range of temperature conditions and get knocked about with road bumps. Result: Like a lot of things "RV," prices for CO detectors for your rig are typically more costly than the ones off the shelf at Homer D. Poe's.

If you’re replacing an older, out of date detector that was originally manufacturer installed, replacement should be fairly easy. Simply dismount the old detector, observe wiring polarity, and reinstall the new detector following the instructions included. Many OEM detectors are "hard wired" into the RV 12-volt system. However, before you go shopping for the new detector, make sure that it is rig-powered. If you buy a new detector that "looks" for 12 volt RV power and your old one was battery powered, you’ll be up to your neck with a wiring issue.

If your new detector wants 12-volt rig power and there are no handy 12 volt wire stubs you'll have to locate a source of 12 volt power near our installation area and run the wires out to it. MAKE SURE the wires are not switched, that is, you can’t accidentally shut off the power to the wires you tap into. Lighting circuits are a good bet, but they should not be switch controlled.

Where should CO detectors be located? CO is slightly lighter than air, hence it rises. So putting the detector above the floor is right. You might even place it on the ceiling, but generally about five feet above floor level is best. If you have a big rig, make sure you install it close to your sleeping area so you’ll be able to hear the alarm when you’re asleep. Of course, follow the manufacturer’s instructions on "siting" the unit.

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Friday, July 20, 2007

TV Antenna Amplifiers v. Power Supplies

Bless the heart of old John Winegard. A "Depression Era" child, Winegard started his fortune in the 1950's when he designed, marketed, and manufactured his first television antenna for home use. But it wasn't until the 1970's that the Winegard family "discovered" the RV market. Says Winegard's son John (now company president since his father's death), "The technology for the Sensar TV antenna was my father's, but it was invented about 24 years ago. In fact, the patent had almost expired when we discovered a new market."

Since that time, Winegard antennas have been a mainstay on most RVs built in the US. Seems like everyone cranks up their Sensar and pulls down on that little round handle, seeking a good TV signal. That is, until something goes wrong with that little white box in the wall. Then it's time for the replacement. But which one is it?

Which one? Well, that's the question. The little white plate that connects the antenna coax cable to your television comes in more than one "flavor." There are amplified Winegard antennas--ones where an amplifier is built right into the antenna up above roof level, and those that have no amplifiers. They're two different breeds of cat, and you can't replace one with the other. Most (but not all) present day Winegard RV antennas have the amplifier built into them--for these you need a power supply block. This system runs 12 volt power up the coax to the antenna mounted amplifier and allows TV signal back down. For the non amplified antenna, you'll need a amplifier block. This amplifies the signal in the block, and doesn't run any power up the coax.

There are other Wingard plates too, designed for "satellite" connections too. Stark Electronics has a great web page where you can eyeball the differences. Nearly any RV supply house can set you up with the proper replacement. Incidentally, older Winegard power supply blocks often had "slide" style switches to turn the power supply off (and at the same time allow for a "cable" connection). The newer blocks have a push button. We found, much to our "designer sense" chagrin, that the new style block is clearly imprinted "WINEGARD." Unfortunately, they way our rig is "plumbed" we had to install the power supply block upside down. Result? We have a DRAGENIW power supply.

Troubleshooting? If the wall plate light doesn't turn on, check for power. With your multimeter set to the appropriate DC range, carefully probe into the "socket" of the wall plate--with the positive probe going to the center conductor and the negative to the outer shell of the socket. If you don't have power, track down the fuse that supplies power to the wall plate. Remember, these little babies don't like to supply a lot of power--typically 8 amps or less is the limit. Plugging in a hair dryer or an inverter with a load of much more than 60 or 70 watts will "blow" the fuse.

If power is present in the socket and the light is out, it's a likely bet the block is blown. Plenty of RVers have complained that corrosion seems to be a huge killer of these critters, so don't be surprised to find "the green" on your circuit board. When you do work at replacing your power supply, it's best to turn off the power to the block. Usually you can just pull the fuse to that circuit, but if you can't discern which one it is, then disconnect the house battery and the shore power (that may be supplying 12 volts through your converter). Unscrew the wallplate and carefully examine the wiring layout.

The coax leads are easily confused, and if wired back wrong will definitely foul up your evening of entertainment. Three terminals are provided, one from the antenna, one from "cable," and the other goes out to another TV set. If you're clumsy like me, tag 'em as to location on the block before you pull them off. And don't mix up the power wiring, you'll blow the block into eternity with a reversed polarity situation.

Got everything connected up right? GENTLY push the innerds back into the wall box and with gentle sensitivity put in the plate screws. Torque them gently--too far and you stand a chance of cracking your face (plate).

Photo courtesy Winegard Corporation

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Friday, July 13, 2007

Wiring Woes? Diagrams Defuse Difficulties

It wasn't but a few minutes after we'd been doing a little roof work on our "camper project," that another problem surfaced: All the fluorescent lights and the bathroom light "quit" working. What happened here, let's see. Ah, yes! The luggage rack seemed a little wobbly, as did the roof access ladder, and a new set of lag screws had been introduced to try and shore up the situation. Did one of those new screws sabotage the circuit? (Word freaks, stick around, we'll discuss that old origin of "sabotage" question at the end of this entry).

Poking around in the fuse panel revealed a definitely "blown" fuse, but was this the whole story? If only we knew just where the wires ran, it would make the whole job of trying to resurrect the lights much easier. Since the rig is an "orphan," -- it's manufacturer having gone out of the camper business long ago, we despaired. However, a Google search led us to others who had success in finding diagrams for their more current rigs. Hence, we took courage and phoned phleetwood. A sympathetic listener at the other end of the line took the request, even called back later asking for a VIN number, and next morning, hot off the e-mail, a five page wiring schematic for our out-of-production rig.

Long story short department: It didn't take long to figure out a pretty likely "point of impact" for our errant lag screw. We'll attack the roof shortly, and armed with the schematics, if worse comes to worse, we may have a hand on a "work around" solution if it comes to that. Moral of the story: Even if your rig is out of production, if the company still exists, give them a call and ask about the possibility of getting schematics. They may even give them to your for free!

And a word about sabotage: Star Trek fans, while it's a popular notion that throwing sabots (French for clog) into powered looms could "clog up the works," there doesn't appear to be any credible report of such a sandal scandal. More likely, since the word sabot can also be reckoned as a literal clog, the sound made by someone clunking around in clogs leads to the word, saboter. Such walking was oft associated with clumsiness, and later extended to deliberate clumsiness that damaged machinery.

Photo: Looks like the tech writer after a bad day searching for shorts. Credit DerrickT on flickr.com


Tuesday, July 10, 2007

RV Extension Cord Safety

Ever come up just a "scoatch" short on managing to plug your RV shore power cord into the outlet? It's a frustrating experience, and there's always the temptation to use an adapter and a light duty extension cord to make up the difference. Please don't. Electricity is a funny thing--when too "light" a wiring is used, not only do you endanger yourself with fire, you also run a good risk for your expensive RV equipment.

Here's the deal: Electrical wiring actually does have a certain amount of resistance to the flow of electrical current. The longer the run of wire, the greater the amount of resistance. As the current struggles against this resistance, it produces heat energy--hence electrical cables can actually get hot--sometimes hot enough to create that hideous problem known as fire. What usually "goes first," however is the under-rated fittings on the end of the cables. These can overheat and burn up, or on the way to that create even greater resistance to electrical flow. But even if that doesn't occur, the resistance of the wiring actually reduces the amount of voltage that can reach your RV.

So if you have too small an extension cord out to the RV, and then fire up a big power consumer--on these days we think of the air conditioner, and not enough voltage is present, then physical damage can happen to devices that need that power. So how do you work with this problem? Well, you could purchase a ready-made RV extension cord. For the 30 amp RV crowd, a 25 foot cord will probably set you back as much as $50. For the 50-amp users, that same length could run you over twice that price.

Tempted to "do it yourself," and build an extension cord? It's do-able. But you need good working data on what size conductors to use in your cord. Here's a link to a site that can help you calculate wire size requirements for a given load. But as you run your calculations, be sure to take into account the length of your existing RV shore power cord. One of our rigs has a 25' shore power cord, so building an additional 25' of extension cord would require figuring a full 50' run. Whatever you do, don't skimp on the wire gauge or the fittings.

If you decide to build your own, always double check your connections before putting your cord into service. We use the ohm meter portion of a digital multimeter to verify that everything it where it should be. Imagine our surprise when we completed a cable and we found two of the conductors reversed. How'd that happen? Squinting through bifocals at the included wiring diagram for one of the fittings, a slight misinterpretation of what the fine print and finer arrow we're pointing to led to what could have been a real problem.

If you're the least bit squeamish about your ability, drop the bucks on a commercially built unit.

And one more thing, when you use any shore power cord, it's never a bad idea to pull all the shore power cable out of the compartment before hooking up and using the shore power. Why? Well, since cable does have resistance, if you put enough load on your shore power cord, you could actually have the equivalent of a "heating cable" in your cabinet--like those things those poor folks in the north use to keep their pipes from freezing in winter.

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Tuesday, July 03, 2007

Charging Batteries Safely

A news item out of Yuma, Arizona, last month points to a couple of reminders--and a product lead--that could affect your safety as an RVer.

Imagine waking up at one in the morning with your smoke detector going off, and that awful sound of a roaring fire outside your bedroom door. It happened in mid-June to a Yuma couple, who were planning an outing with their motorhome. Apparently having a low battery problem with the motorhome, the owner had hooked up a battery charger and left it. Sadly, the battery overcharged, and the resulting heat ignited a fire. In the end the motorhome and the family home were completely wiped out. You can find the whole story on the Yuma Sun website.

We've been around battery chargers since we were 'knee high to a married grasshopper' and some of the "oldy" chargers that our pappy's owned were probably hanging around when they were knee-highs themselves. It just seems like battery chargers are one of those products that rarely give up and die. As a result, many of us are limping along on ancient technology that may work--albeit inefficiently--but can (as it apparently did this time) lead to tragedy.

A lot of us use portable battery chargers, and many of these fall into the category of what's technically called an "unregulated charger." Hook it up, the charger delivers a charging voltage (higher than the "rated" voltage of the battery) and just keeps a charging. The battery voltage increases as it charges up, and it will eventually reach a point where the electrolyte will literally boil. An unregulated charger needs to be monitored. Yes, with this type of charging system, you would want to occasionally hit the boiling point to "equalize" the charge in the cells. However, if you "cook" them too long, you'll kill the battery, or even worse--lead to a fire danger.

A complete discussion of battery charging is an appropriate topic--and we'll cover it in a future blog entry. Now, however, we make this point: For many it's simply safer, and far more efficient, to use what is termed an "intelligent charger." An intelligent charger recognizes the state of the battery's charge, and supplies exactly what is required at any given stage in the recharge process. Enter the Xtreme Charge maintenance charger. A relatively inexpensive ($99 list) charger, Xtreme is an "intelligent charger" that also adds an additional benefit: This charger "pulse charges," inducing a wave into the charging current that breaks up sulfate crystals in batteries. These sulfate crystals, if left to themselves, will eventually kill off an otherwise good battery. The Xtreme can be left hooked up to the battery, and it will maintain a safe current level, along with the sulfate-eradicating pulse.

Xtreme's manufacturer sent us an evaluation unit a couple of months ago. While we're still testing it, so far we've been pleased with it. It's a small unit that can fit in many battery compartments, and even if it won't it's weather proof, so you don't need to worry about a passing rain shower shorting out your system. While the specs indicate the Xtreme is designed for battery systems up to 150 amp-hours, the company whiz-kids tell me that it will work with larger systems, but its relatively low (2.5 amp) maximum charge current will take a while. Amen to that. For a larger system, consider the Xtreme a good investment in battery maintenance, rather than full-scale charging. Find out more at the Pulsetech website.

There are also "intelligent charging" systems available on many after-market (and some OEM) RV converters--those little devices that convert shore power into low-voltage power, suitable for use by RV interior lighting and other uses. In any event, when you hook up a charging system to your RV batteries, make sure you keep an appropriate watch on it--particularly if it's an unregulated charger.

Fire Photo: Yuma Sun Charger: pulsetech.com

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