30-Amp, 20-Amp Cheater Boxes

I was recently given a setup which has a 30-amp plug on one side and a 20-amp plug on the other side. The output is a 50-amp plug. I was told that if you plug in one side to a 30-amp source and the other to a 20-amp source, you will end up with 50-amp. Do these things actually work? No brand name on it, so I assume they are homemade. (Jerry M.)

Jerry, what you have is called a “cheater box” and though some are indeed homemade, there are a couple of suppliers that have them available online (as pictured). I do not recommend cheater boxes for a couple of reasons. First and foremost, they are not “approved” for RV use. Safety is paramount and I would never recommend something not approved for RV use. In most cases, the 20-amp receptacle at a campground will be GFCI-protected (it is a code requirement). Cheater boxes will automatically trip that GFCI breaker and you’ll only be provided power from the 30-amp side. 


Also, if the 20-amp receptacle and the 30-amp receptacle are connected to the same electrical phase, the cheater box will not function. To my knowledge, most 20-amp and 30-amp receptacles in the same pedestal at the same site are indeed wired to the same phase. If each receptacle is connected 180-degrees to an opposite phase, it might work. However, if there is an EMS (electrical management system), installed in the coach, or a sophisticated inverter/charger in the system, the cheater box will likely not function, or possibly add confusion to the EMS. 

Furthermore, you cannot use a cheater box with surge protection. They simply will not allow the voltage to pass through to the RV. Another reason is the sizing of the conductors. The neutral wire in the cheater box feeding its 50-amp receptacle must have the capacity to carry 50-amps as provided by two, opposite-phased sources of 120-volt hot wires. 

And finally, they’re called “cheater boxes” for a reason. If the campground is not aware of you using a cheater box, you’d simply be using more power than what it is expected of you (and charged accordingly by the campground owner), in those rare instances when the cheater box might actually work. Indeed, when all the right circumstances are correct, including permission from the campground owner, they have been known to work. A lot depends on how that particular campground was electrically constructed. 

The bottom line is that I consider it risky to use a cheater box. It’s much better to connect a 50-amp coach to a 50-amp receptacle. I’m not even fond of those 30-50 adapter plugs because it eliminates one of the safety factors built into the RV. FYI, the new 2017 electrical code for campgrounds calls for more 50-amp sites in campgrounds, so hopefully the park owners can keep up with the demand. The smart campground operators are already upgrading their parks to accommodate more 50-amp sites since more and more RVs demand the higher ampacity than ever before.

rvt#814

What's that Receptacle?

Dear Doctor, I just bought my first RV. It is a Winnebago Minnie Winnie 25B. I didn't receive any manuals so I am learning as I go. What is the service receptacle in the electric cord compartment? It says close when not hooked to outside power. I have left it open since I got it 6 weeks ago. I am also unclear if the house battery disconnect switch should be left on all the time, even when hooked up to outside power. Is this connected to my engine battery and if it is left on will it drain the engine battery? I have heard many different viewpoints. Thank you! Cathy R.

Cathy, if what you are seeing looks similar to this photo, that is the RV's generator output receptacle. In order for the generator to power the coach, the shore cord must be plugged into that receptacle. Some larger motorhomes come equipped with an automatic transfer switch that makes the connection automatically soon after the generator is started. But on some of the smaller coaches, in order to power the coach with 120-volts AC electricity, the shore power cord must be plugged somewhere; either into the pedestal at the campground, or into that receptacle inside the compartment.

When activated, the house battery disconnect solenoid removes the battery from the system during a period of storage or non-use. The house and engine batteries remain separated so it will have no effect on the engine start battery. Also, if the solenoid is activated while the coach is plugged in to shore power, the battery charger will not be able to charge the house batteries since they are now “disconnected” from the system. So typically you’d activate the disconnect switch during storage so the battery won’t be drained. But when using the coach, leave it off.

Smoke Gets in Your Eyes

I'm trying to find out what I have to do in order to fix this power issue. When I last parked my trailer I plugged it into a 50 amp shore power source. Then while trying to raise the power jacks in order to unhook the truck, the switch wouldn't work. It was like there was no power at the switch. So I clicked the battery power switch on in order to use the battery power. It worked fine but after raising the trailer I noticed and smelled smoke. It was like a burning electrical smell. I opened the door for the garage and it was full of smoke. After the smoke cleared I'm pretty sure the smoke was coming from the electric motor that raises and lowers the power jacks. After this I started looking into the problem further and noticed one of the electric breakers that controls the power converter was tripped off and it would not stay reset. Then I unplugged from the 50 amp and with the plugin adapter plugged into 30 amp shore power. That seemed to fix everything and I've been running it that way since (about 3 weeks). I have the trailer for sale and don't want to sell it without fixing this issue. Please point me in the right direction. I don't want to call an RV repair dealer because I've been ripped off by them before. Thanking you in advance... Gary S., (Lisbon, OH)

Gary, with all the accoutrements that come with a coach that large, the 12-volt power demand is huge. Some manufacturers fail to let their customers know about the vital importance of having enough battery power to operate all things 12-volt. Plus that battery disconnect switch must be off in order to have 12-volts distributed throughout the coach. I’m not sure how many batteries are in your bank, but it’s doubtful the full load of those landing jacks lifting that much weight can be adequately provided by the converter/charger alone. There may be something internal to the converter that is not allowing it to fully charge the battery bank, but the symptom suggests a low amount of voltage in the batteries. When connected to 30-amp shore power, is the converter still in operation? With less power available, it’s possible the converter/charger is not being powered by 120-volts AC from the shore line at 30-amps service. If you send me the brand and model of the converter, I can delve deeper into that device.

Another thing some RV makers fail to understand is the negative side of the DC system. Be sure the negative cables are greater than or equal to the size/amperage rating of the positive cables. The high current demand of the landing jacks under load could have overheated the motor by a lack of proper grounding. If possible, fully charge the battery bank independently of the converter/charger and see if the jacks operate normally. If so, we can focus attention to the converter itself.

With 50-amp service and the converter operational, is there a voltage increase, as measured at the battery bank? It’s possible the converter is undersized for the 12-volt demands of the entire coach. Adding the high current demand of those landing jacks possibly overheated the motor causing it to smoke. Typically they are protected by an internal breaker so hopefully no internal damage exists. Have you noticed other 12-volt devices with problems? Dim lighting, slow fan speed on the furnace, low water pressure from the pump, etc.? If other devices exhibit problems, I’d focus on the ground cables and all connections, plus the state of charge of the batteries.

Loose connecting points can also cause overheating and smoke. If the problem is dedicated to only the powered landing jacks, then it could be a problem with the jack motor or possibly the converter. Another question; do you have a power management load center? One that sheds loads if power consumption is exceeded? When operating on 30-amp service, some devices cannot operate unless the management load center can make that decision based on load requirements. Sounds confusing, I know. But until we have some specifics about the individual components, we're just guessing.

Send me the specs on the converter/charger and the landing jacks, and how many and what type of batteries are in the battery bank and I’ll dig further. There’s a logical explanation in there somewhere.

Fluctuating Line Voltages in Motorhome

I have 2013 Endeavor 43RFT. The Power Control System Central Monitor Panel is showing that the L1 and L2 voltages are fluctuating 3-volts every one to five seconds, (e.g. 118v then 121v then 118 then 121 etc.). Per Monaco Help Line, I have tightened all the screws in the distribution panel and in the transfer switch. This occurs whether I am on shore power or generator (but not when inverting). Monaco Help Desk could not offer any other help, how about you? My inverter is a Magnum MS-2812 and the transfer switch is SurgeGuard 41260. Jim L. (Huntsville, TX area)

Jim, this particular transfer switch does not contain any electronic components and is reliable, so we can rule out any problem with that device. And your inverter likely produces a purer sine wave than that off the grid, so that leaves only the coach loads as the possible suspects since you’ve already addressed the connections (be sure you've checked and tightened them all). The next thing to do is to isolate the problem to a specific circuit, then locate the culprit component within that circuit. 

Start by powering up the coach (either by shore power or generator), and turning the branch circuit breakers off completely. Monitor the voltage with all the branch circuits disengaged; the voltage should not be fluctuating at this point (if it is, there's likely a problem with the source voltage itself). Then turn on each breaker one at a time and allow the voltage to stabilize. If the voltage begins fluctuating after turning on a specific breaker...that’s the circuit with the problem.

Next determine which component(s) that circuit is powering. It will likely be something equipped with an overload device that automatically resets such as the heating element in the water heater. Something is causing the current usage to fluctuate, which results in the voltage variances. If you cannot locate the specific component within that circuit, a voltage drop test can be performed to determine exactly where the current leakage is occurring. It could simply be worn insulation on a conductor somewhere if it’s not the actual “load” causing the fluctuation. Unfortunately, it is best left to a professional electrician, one with an understanding of RV electrical systems, to dig beyond this point.

You might want to refer to the coach wiring schematic to determine which components are on each circuit as a guide and have each component tested independently. Even though it may take a Certified RV service technician, the current leakage or fluctuation cause has to be there somewhere! It's pretty much a divide and conquer troubleshooting process.

##rvt751
 

Winterizing and Electrical Questions

I recently purchased a 2007 R-Vision Trail-Lite RV. I live in Iowa and am trying to winterize it but when I put the RV antifreeze in, I can’t get it to circulate throughout the system. Am I doing something wrong or do you think I have a bad pump? The owner’s manual has very sparse information. I also have a couple of plug-ins that don’t have any juice. Do you happen to know where I can get an electrical diagram for this camper? Thanks! Bill A. 

Bill, the easiest way to induce the RV anti-freeze into the system is to pour a couple gallons directly into the fresh water tank and allow the 12-volt pump to pump it through the system. Are you saying your water pump won’t operate at all? You can also empty the tank, disconnect the hose leading to the water pump inlet and insert that hose into a bottle of RV anti-freeze, but that still requires the RV’s water pump. There are also kits available that attach to the kitchen faucet where you can “back fill” the system using a manual hand pump. Some RVs are equipped with a "tee" fitting and valve located between the tank and pump that permits a short section of hose to be inserted directly into the bottle of RV anti-freeze. These types of kits can easily be added after the fact. Some even come equipped with a separate, permanent tank for the anti-freeze. Let me know if you are experiencing a water pump issue. But if it pumps water, it will pump anti-freeze.

I’m assuming the “plug-ins” you refer to are 120-volt AC receptacles. If all the circuit breakers are turned on and you do have power at other receptacles, check the GFCI mounted in the lavatory or galley. It’s likely tripped and is protecting more than just that receptacle. Simply push the reset button and then check those other receptacles. GFCI’s are usually configured to protect the bathroom and/or galley circuit PLUS all other receptacles installed downstream of that one.
Personally I do not have source for an electrical diagram (if one even exists). R-Vision does, however, have an active club online at this website. But alas, you must be a member to search the forum. I'd suggest you join that organization (it's free) and see if any of the members have access to the diagram you are looking for. Individual brand RV clubs are great sources of information, from owner to owner. Almost certainly you'll gain additional help from that group.

##RVT769;##RVT917

RV Generator Over-Voltage

Doc, I recently went to exercise my RV generator and I was surprised when at about 5 minutes after turning on the generator I saw the voltage meter running at about 160-volts and it suddenly sparked but kept functioning. We turned on the AC and all the lights, although one blew. It looked to be to bright. Even with everything on the RV on it brought the voltage down to about 140-volts. I am assuming this is not a good thing and possibly dangerous. I thought it was supposed to be around 120. Can you tell me how this happens? It was running fine before I took the RV to have it serviced. A belt was squeaking and they repaired that but now I have a problem with the generator. Also you advise not running any equipment while the generator is putting out this much electricity. Unfortunately I have run my AC's while it was doing this. They seemed to run fine. But since I have done it is there some maintenance step I should take at this point for them? Again thanks for your assistance. Dale V., (Nashville, TN)

Dale, there are a few reasons why any generator may get out of adjustment depending on the condition of the unit, the number of hours, etc. It’s always been a good idea to have the generator tested annually using a load bank. The load bank device can monitor the voltage (carburetor) and the frequency (governor) as incremental loads (amperage) are placed on the generator. It’s possible someone tried to adjust the generator engine by ear or by sensing how smooth it runs, etc. I mention this fact in my articles, videos and in my seminars, but ANY mechanical adjustment done to the generator has a predictable electrical result. That’s exactly why a tech cannot tune a generator by ear.

Normal wear, carbon buildup, poor quality fuel, bumps and vibrations, etc., can all affect these finer adjustments. Combined, they create the reasons why it’s important to have the RV generator attached to a load bank... I say every year, but no less than once every two years.

If your air conditioners survived 140-volts AC for a long duration, you were quite lucky! Roof A/Cs are quite susceptible to very high and very low voltages. There’s nothing to check on the A/C units if they operate properly on shore power. If they operate correctly on shore power, no damage was done. Also, by connecting to shore power you can check all other AC system components to see if any were damaged by the high voltage. But be sure to have the voltage and frequency checked on the generator by a specialist equipped with the proper diagnostic testers before relying on it. The safe spectrum for AC electricity, (by any source), is 120-volts AC, +/- 5%. 

More RV Electrical Info

After attending several RV shows and joining you for a few RV Doctor seminars, my wife and I have purchased a Fifth Wheel (a 2010 Peterson Excel Winslow. We are very happy that we did our homework and now have a high quality RV that will hopefully last many years.

 My first maintenance related question is electrical. I have purchased a Progressive Industries 50-amp surge protector that plugs in at the pedestal and has a digital readout of voltage, amps being used, cycles and error codes. It will trip the power to the RV if power has the wrong polarity, and has several other features to protect the RV. 

At the Seattle RV show, you said it was a necessity to have a non-contact proximity tester, but with my surge protector, I think I am covered. Please confirm. I will probably pick up a Fluke volt meter for general usage.

Also, another question: When plugging in the surge protector to the adapter, the weight of everything tends to pull the plug out of the socket. I used a bungee cord to wrap around the pedestal to keep it tight. The other issue when it rains in the northwest is wet, not dry. Can I use a waterproof cover over the entire pedestal, adapter and surge protector to keep the connections dry?  Mark & Cindy A., (Bainbridge Island)


Mark & Cindi, the Progressive surge protector is a very good device and is certainly recommended for serious RVers. What we have found, however, is that neither the Progressive nor the Surge Guard models can protect against the dual fault situation called Reverse Polarity/Bootleg Ground (RPBG). It has been well documented by my buddy, Mike Sokol. Check out how and why the RPBG situation can even fool expensive ground loop impedance devices and those inexpensive three-light testers that everyone relies on; read this article carefully and be sure to click on the internal links!

The only sure-fire way to verify the polarity of incoming voltage from a campground pedestal, and the most logical and safest for RVers, is the use of a non-contact voltage proximity test device. I consider it cheap insurance....that might just save your life.

Also, I’m not a big fan of plugging a 50-amp RV into a 30-amp receptacle for the simple reason that it eliminates at least one of the safety devices built into the design of the pedestal. It’s certainly better if you have an EMS (energy management system) controlling your distribution inside the RV, but you may find that only using one leg of the incoming 120-volt AC electricity limits what circuits are actually activated inside the coach. Now that said, in some cases with the smaller or older campgrounds, you may have no choice if all they have are 30-amp pedestals. In those instances you simply deal with it until you can get connected to the proper source voltage once again. Always use a quality 50-30 reducing adapter (I recommend the ones that have a short piece of cable running between the male and female plugs rather than the big chunk of rubber with both connections molded into one plug). Also, ya gotta keep that connection clean, dry and tight no matter what, somehow! Bungee straps, plastic baggies, etc., can all help. Have you considered the unit that installs permanently inside the storage bay rather than the portable unit that attaches at the pedestal? Just a thought...

 

Dog Bones & RV Batteries

Thanks for your information at the RV show last weekend. Your seminars were very informative and those tire pressure requirements were new to me. Also you mentioned the dog bone adapter is a not a good idea. I’ve used them for years with no problem. How can I plug my 50-amp trailer to the 30-amp post at the campground without one? What do you know that I don’t?

What do you think about solid state batteries? We live full time in our 5th wheel and currently have two lead acid 12-volt deep cycle batteries. Weight seems to be a good thing with the solid state and they are available in a higher amp-hour rating, (but for a price!). Or shall I upgrade to four, 6-volt batteries in a parallel/series configuration? Thomas S., (Seattle, WA)

Thanks for coming to the seminars Thomas! Glad to hear you liked them! About those dog bone adapters....only use them if you absolutely have to. The biggest concern is that one or more safety devices are bypassed when using them. Plus more connections in the chain gives moisture intrusion and electrical corrosion a leg up. But if all you have available is a 30-amp receptacle, unfortunately you’ve got to use one. But try to always plug in to the correct receptacle so you can have full operation of all your components and circuit protection. Here's an industry expert's similar remarks about those dog bone, reducing electrical adapters. Check out this short video. 

I’m not quite sure what you mean by a solid state battery. Do you mean a sealed battery like an AGM? Do you have a specific brand in mind? Upgrading your battery bank to four, 6-volt batteries would be a huge advantage! You would more than double the amp-hour capacity, in most applications. Just remember, you’ll then be required to have the capacity to charge that new configuration also! 

##rvt749--dog bones
 

GFCI Hums in Class A Motorhome

I have replaced the GFCI in my Class A motorhome and the new one hums when the inverter is on. Do you know why? Denise D.

My immediate thought is that the new one simply does not know the words Denise! Or it might have something to do with an internal line balance-detecting transformer (more likely). This, of course, is assuming no modifications were made to the wiring at the inverter itself. None would have been required if the inverter was installed correctly to begin with. The humming could also be related to the type of inverter in the system. Is it a true sine wave inverter, or perhaps it has a modified square wave output form. 

All GFCIs have a set of contact terminals labeled “Line” and another set labeled “Load.” The black and the white wire, (hot and neutral) from both the line and the load must be connected to the correct terminals on the GFCI. If, for instance, the hot wire from the line is wired to the “Line” terminal, but the neutral wire from the line is wired to the “Load” terminal, it will confuse the GFCI. The main purpose of the GFCI is to monitor the balance of that circuit between the black and white conductors. Mis-wiring the hot or the neutral at the GFCI may render it inoperable, but not to the point of actually causing it to trip. Nor will it likely trip the circuit breaker for that circuit. 

Here's something you can check; be sure the coach is not plugged in and the inverter is off before proceeding. With the GFCI removed from the receptacle box, there should be two sets of Romex conductors located in the make-up box. The black and white wires from each must be kept relevant to each other. In other words, the same pair of black and white conductors must attach to the correct (line or load) terminals on the GFCI. With the motorhome plugged in, the “line” set will be energized; the “load” set is everything else downstream of the GFCI and will not be hot when the GFCI is tripped. There is a remote chance the new GFCI is faulty, but chances are it is simply a case of incorrect wiring. I’ve actually seen all the white wires bundled into one wire nut behind the GFCI; a no-no for GFCI wiring. It is best to have a pro RV service tech take a look if you are unfamiliar with working on a live circuit. I certainly don’t recommend it. The circuit must be energized at a certain point in order to differentiate between the line-hot and the load-not hot sets of wires at the GFCI. I know this may sound a bit confusing, but a pro tech with an accurate VOM will be able to quickly discern the problem with a few simple measurements. 

##rvt755; ##RVT857

Cooking My RV Batteries

Can you give me some important tips on storing my RV? I park my RV behind my garage and plug in to a 30-amp shore power cord. I have discovered that my battery bank of two, Group 27 batteries are "cooking" and I don't know why. Sure would appreciate any input. Dee S. (Seal Beach, CA)

Dee, aggressive overcharging by the on-board converter/charger would likely be the reason the batteries appear to be “cooking.” Many RV converter chargers are equipped with, what I call, mediocre technology concerning the battery charge function. They serve as outstanding converters (converting AC electricity to DC electricity), but lack the complexity of a processor-controlled battery charger. Many common converters force the maximum amount of current into the battery bank at too high of a voltage rate. Some may taper the amount of amp-hours (current), but it takes special and specific charging algorithms to push the correct amount of current at the correct amount of voltage at a rate that is advantageous to that type of battery, all the while considering its state of charge at that moment in time. 

As a battery charges (accepts and stores amp-hours), the voltage and current rate must constantly be evaluated and modified to ensure that any given battery will not be overcharged or undercharged, yet charged fully. A sophisticated, processor-controlled, three-step charger is needed to accomplish this. I’m a fan of employing the stock converter as a converter only, but to add an aftermarket, multi-step battery charger to be solely in charge of keeping the battery bank(s) fully charged while connected to shore power. The newer technology allows for an RV to be kept plugged in all the time, without the risk of overcharging or “cooking” the batteries in the system. Some are applicable to the various types of RV batteries; wet cell, AGM, gel, etc. I would suggest you upgrade at some point. Until then, if you opt to leave the coach plugged in all the time, be sure to inspect the condition of the batteries every couple of days. Unplug the coach or disable the converter, (simply turn the circuit breaker off), if overcharging or gassing at the batteries is discovered. 

Some RVers have used a timer placed in the AC circuit of the converter to only allow it to operate at certain times. But I’d rather see the stock converter convert and a separate battery charger charge. 

RV Generator Cannot Carry a Load

I read your column with much interest and one question regarding inexpensive water heater bypass valves in a recent issue caught my attention as I had a similar problem with my fifth-wheel. In my unit the hot water pressure was very low and flow was slow but the cold water was full bore at all taps. Living here in Calgary I had stored my unit for a lengthy period in a winterized condition and that was exacerbated by a delay. I now have an older Rialta and until this year all was fine. Now the generator will start and run with no problem and I can turn on low load lighting without trouble, but as soon as a load is placed on it like the air conditioning or microwave, it quits right away. Any ideas for a fix? H. Greuber, (Tucson, AZ)

Hank, depending on the number of hours on the generator and how old it is, it just may be time for a set-up/tune-up. All RV power plants require regularly scheduled maintenance. Adjustments to the carburetor and possibly the governor may be in order. A certified RV service technician can quickly diagnose the generator by connecting it to a device called a load bank. RV generators cannot be tuned or set-up by ear and I caution the service technicians I teach that every mechanical adjustment on the generator has a direct electrical consequence. 

Unfortunately, this one is better left to a pro technician because of the specialized equipment necessary to diagnose it. No load and full load voltages and frequencies must be within spec for the generator to carry a rated load. You can rule out a fuel issue by inspecting the fuel line from the tank connection to the generator connection. Old rubber fuel hoses can crack and begin sucking air, which could lead to operational ills when a load is applied. You might also try running the generator from a separate fuel source, then applying the load. If it quits again, you'll know the problem is in the generator and not the fuel supply.

##RVT776; ##RVT877

Burned Wires in IOTA Transfer Switch

I just found my IOTA, 50-amp transfer switch smoking badly. I opened it and found all the wires burned up inside. I found a recall; NHTSA Recall No. 12V-516, and it does involve my unit, but I have a 2010 Cameo and they went out of business, so I think I'm at a loss here. My question is, do I even need this thing? I don't have an in-house generator. And it's only there from what I can figure out, to transfer from shore power to generator power if I loose shore power. Is that correct? Can I just wire around it? It looks like I can connect the inbound wires from the the pedestal to the wires going to the inside circuit breaker box and eliminate this auto transfer switch altogether. The other wires go to an inside, built-in generator switch and the heavy wires appear to go to the generator, if I had one to connect to it. Can I just eliminate it? Bill K. 

Along with the recall, the Internet is rife with problems associated with that IOTA transfer switch Bill. I see no problem with you removing it altogether if you do not have a generator OR an inverter. Be sure to use an approved, listed electrical box to make the connection between the shore cord and the load side of the coach’s system. It can be mounted right where the transfer switch is located now. Tape the wire nuts securely also. I would also label the generator-ready wires inside the proposed generator compartment to alert future owners of that coach that a modification was made. Leave the conductors in place but label both ends of the generator circuit just in case someone eventually installs a generator. 

A transfer switch (either manual or automatic), is only required when more than one source of 120-volts AC is available to power the coach circuits. Some transfer switches control all three available RV sources; shore power, generator and inverter. In an RV equipped with only a shore cord connection, the conductors simply end up at the main panelboard breaker box anyway. There is a junction box somewhere in the circuitry of those coaches that transitions from the stranded shore cord conductors to solid romex wires inside the RV. So without a generator (even though it's prewired for one) and no inverter, you can safely bypass and remove that failed IOTA transfer switch.

RV Hot Skin

I read in a recent issue of Family Motor Coaching your advice to Michael regarding the use of a proximity tester. I am a retired electrician with almost 50 years on the job. Almost 20 years in hospitals and the rest in industry, some construction and the rest maintenance.

Your advice about the proximity tester was a bit off base. That type of tester is a great troubleshooting tool in the hand of a professional, but not so good for the novice. A far better choice for the novice is a circuit tester/ ground monitor. The device is not much bigger than the plug on the end of an extension cord. These testers will check reverse polarity, open ground, open neutral, reverse hot and ground and open hot. 

This tool can be used at the end of an extension cord, at the 120 volt outlet or inside the RV. It is safer to use and gives more information. Like all electrical safety testers this tool should be tested on a known good circuit before testing an unknown circuit. In this case to be sure all of the lights are working. Dave S.

With all respect, I beg to differ Dave. Those three-light testers cannot identify a certain scenario containing reversed polarity along with a bootleg ground. Those two faults, when coupled, even fool digital volt/ohm meters and ground loop testers and all the RV surge protectors now on the market. And results in everything metallic in and on the RV becoming electrified; what we call a hot skin condition. We’ve found that by measuring the voltage with a reliable volt-meter and then verifying that voltage with a proximity test device is the safest way to determine the true polarity of any receptacle. Remember, on RVs, the ground and neutral conductors are isolated from each other. Only at the voltage source is the ground and neutral bonded.

My buddy Mike Sokol (a frequent contributor here), had an interesting article published in EC&M magazine. All serious RVers need to check it out; it explains the reasoning behind our recommendation.
 
The other advantage using the non-contact proximity test device, which is totally safe for the novice by the way, is that no conductors need to be exposed or circuits interrupted. All you have to do is get close. It’s perfect for testing for a hot skin condition.

Mike has produced a bunch of videos that show the advantages of hot skin testing using the proximity test device. I feel this topic is so important, every RVer needs to read through all the reference sources.
 

Generator Difficulties

I recently purchased a used Class C motorhome to pursue a few interests on my "bucket list". This is my first motorhome and everything worked and within four days of purchase I made a trip to Mt. Rushmore and Devils Tower. I made a total of fourteen trips last year. Some in campgrounds and just over half dry camping. My problem now is with my 4.5 Kohler generator, which until now has worked wonderfully. While dry camping I had the generator running when it suddenly stopped. It will crank but not start. Visual checks look good; there are no loose wires or other problems. The oil level is good. I have fuel to the generator and the plugs have been removed and replaced. I tested for spark by leaving one plug out and could see a spark jump the gap as I cranked the gen. Since the motorhome came without manuals, one of the first books I purchased was a copy of your RV Owner's Handbook. The troubleshooting chart would seem to indicate a possible blown ignition control fuse. How do I locate the ignition control fuse? What else should I check? I'm pretty handy but I'd like to know a bit more before throwing myself at a generator shop. Don C., (Salt Lake City, UT)

Don, without actually taking a look at the generator and the actual installation it may be difficult to diagnose from afar, but I'll give it a try. The fuse protection for the starting circuit is inside the control box on the front of the generator. I can't recall off the top of my head, but it may be an in-line fuse inside that box. But be sure you indeed have fuel getting to the carburetor. Yes, you may have fuel getting to the generator, but make sure the fuel pump is actually pushing it up to the carburetor. 

It's also possible it may be sucking air through a cracked fuel line between the fuel tank and the generator. If the hoses haven't been replaced recently, it may be time to do so now. Inspect the full length of the fuel hose and see if there are any cracks in the rubber. It could also be a choke, carburetor or governor-caused problem as well. I’d suggest performing a process of elimination if you’d rather not take it to the shop. Start with verifying that fuel is indeed entering the carburetor. Let me know how it checks out and we'll dig further if necessary. 

Only Half a Cedar Creek

We have a Cedar Creek that we are having a problem with our inside and the outside electrical receptacles. It has no power.  We have checked the fuses and everything looked okay at the panel.  Where do we go from here? It all seems to be on one side of the RV. It's a 5th wheel with 3 slides. Thanks for any help you can offer! Wanda W., (Meridian, MS)

Wanda, the dead side of your Cedar Creek is probably on the same circuit as the ground fault circuit interrupter, (GFCI); probably located in the lavatory. If all the circuit breakers are fine at the panel, the GFCI has probably tripped causing all the receptacles downstream of it to lose power. Simply reset the button on the GFCI and all power should return. The coach, however, must be plugged into shoreline power in order to test and reset the GFCI.

Here's another related question in which I go a little further into detail about the GFCI.  

 

Powering a Pickup Camper

I have a 2005 Lance Light pickup camper. The fridge runs on propane and so does the stove and heater. So all I basically need is power for the lights and stereo system. When using lights and stereo for about three hours, the deep cycle RV 12-volt battery gets low and I have to start my diesel pickup to recharge it from the truck's generator (or alternator?). I don't like all that noise and smoke when out elk hunting. My questions are: can I just use an extension chord coming from my 2000 watt gasoline generator and plug directly into the outside power receptacle on my camper for a power source? And will this also recharge my internal deep cycle RV battery or should I use a battery charger and jumper cables for this operation when using the generator? In other words will a regular 120-volt outlet or generator power recharge my RV battery with the power coming thru the Camper's power grid system? Thomas B., (Worland, WY)

Yes, you can simply plug the camper into any 120-volt AC source to power the camper. Whether it charges your auxiliary battery depends on if the camper is equipped with a charging converter or a simple AC-to-DC converter. If it only has a simple converter you can upgrade to a decent charging converter to charge the battery. I could find no info online as to whether it’s a battery charging converter or not. It should state so in the owner’s manual, however.

When using a portable generator, be sure its internal ground connection is intact. You’ll want to have a good safety ground from the AC power source. When you’re plugged into a campground, it too should be a grounded connection. Also be sure the sizing of the extension cord is suitable for the amount of amperage it will be passing. 

Another RV Electrical Question

What is a safe range of AC voltage (120 + -) for a 50-amp RV electrical system? John P., (Madison, MS)

Sheesh John, can you not be so wordy? (Actually, I love these "to the point" questions!) In my seminars I report that all experts agree that the proper AC voltage for any RV is 120-volts AC, + or – 10%. Any where between 107 and 132 volts AC. It makes no difference if the coach is configured for 30-amp or 50-amp service. It’s all 120-volts AC. The 50-amp coaches simply employ two separate legs of 120-volts AC each. That said, I'd be leery of plugging in at the extreme edges of this range, just to be extra safe. 

Inverter Questions

Where can I find the wiring diagram for a 1989 Citation RV? I have one in NJ. I bought it used and it is having some electrical problems. I don't know what the inverter is used for. I was told that my lights are low voltage (12-volts), therefore I need the inverter. I don't believe it for a minute, but I would like to get a copy of the diagram in order to troubleshoot the problem. Can you help? Gerzan A., (N. Bergen, NJ)

Gerzan, it’s doubtful you’ll ever find an accurate schematic or wiring diagram for a coach that old, even if one existed. But typically, all lighting in an RV is 12-volts DC (direct current). An inverter is the electrical opposite of a converter. It takes 12-volt battery power and inverts it to 120-volts AC (alternating current). By the way, some of today’s sophisticated inverters are also very good battery chargers. When the coach is plugged into 120-volts AC shore power, (or operating on generator power), the inverter becomes a multi-step battery charger. I'm wondering if you're confusing a pre-existing CONverter with a non-existent INverter?

If you have a battery bank, you do not need an inverter to power the interior lamps. The inverter would be used to produce AC voltage so you can power 120-volt AC devices/circuits when shore power is not available. What is the brand and model number of the inverter you have in your coach? Inverters come very sophisticated (true sine wave output) while some lesser expensive models output a modified square wave. If you indeed have an inverter, it’s possible it did not come stock from the factory. Unfortunately, I’ll need a little more information to help any further.

Hurricane Sandy and an RV Air Conditioner

Last night during Hurricane Sandy, the wind forced water, (about a pint), through my roof-mounted air conditioning unit. It dripped through and I was able to catch it in a pan. Will this have ruined the AC motor...or should I just let it dry out and then see if it runs. How do I prevent this in the future? Hilary T., (Sterling, VA) 

Chances are everything is still okay with the air conditioner Hilary. If any of the contacts got wet, they will dry out over time. If you have any doubts, a quick inspection can be performed by removing the exterior shroud and simply looking inside at the contacts and connections. Be sure the RV is unplugged, of course. You didn’t mention which brand air conditioner you have, but all shrouds are removable, but you may have to refer to the owner’s manual to determine exactly how on your model. This is assuming the wind blew the water in through the vents of the shroud and into the return air portion of the unit. If the leak was around the seal between the roof and the air conditioner, then the mounting bolts may need tightening. You can also remove the ceiling shroud inside the RV to inspect the compactness of the weather seal under the unit and on top of the roof.

How to prevent this in the future? Get the heck “out of Dodge” when a hurricane is approaching! Seriously though, if the RV is not being used at the time, you can purchase a cover for it that will minimize the intrusion of rainwater through the ventilation openings in the shroud. If you’re living in the rig at the time, and the wind and rain are blowing sideways, just be sure the drain holes in the pan of the air conditioner are free and clear so the incoming water can drain onto the roof before it has a chance to seep into the living area. Under normal operational circumstances, of course, enough heat is generated by the compressor and the fan motor to typically evaporate any moisture that accumulates. The remaining moisture is simply released through the drain holes in the pan and onto the roof where it either drains off or eventually evaporates.

Since you emailed, I’m assuming you still have power and are safe. I grew up in Florida and went through many hurricanes so I know how frightening that experience can be. Glad you are safe!  

My Honda Generator Will Not Power My Coach

I have a 2011 Fleetwood 40-footer. I am trying to get my Honda EU3000 generator to power up the motorhome for a few items. My display after plugging in will show NO LOAD. This generator will power anything else I try such as a 30-foot trailer with one air conditioner, compressor, etc. I also have a Coleman 5000 and that will power up the motorhome. I have an adapter cord 50-amp female going to 30-amp (3 prong) male. The Honda worked with my 2002 Monaco hooking the same way. The reason I like to use the Honda is when I am at the track this time of year, there is no need to run the motorhome generator since there is no need for air conditioning. I have called Honda and they where no help. John Z., (Purcellville, VA)

Well it appears we're on a steady diet of electrically related questions of late (always a fascinating topic anyway). John, as I mention in my seminars and articles, the 120-volt system in an RV is a little different from conventional house wiring. The RV is wired from stem to stern with an isolated neutral conductor. In other words, the white neutral wires are not bonded to the bare copper ground wires or any metallic component anywhere inside the RV (note the "Insulated Neutral Buss" in the diagram). The bonded (grounded) neutral actually takes place at the electrical service entrance at the campground. 

When running on the generator (or even an inverter), this neutral/ground bond typically takes place internally to those power sources or through the transfer switch. I'm guessing the Honda portable generator does not have an integral neutral-to-ground bond inside, while the Coleman probably did and the EMS system sensed this "open" and shut your system down. I'm not totally privy to all the innards of portable generators since my focus is usually with those RV-approved components such as installed RV generators, but I believe this is what's happening. I'm also guessing the reason the Honda worked fine with your older Monaco is simply because the Monaco was not equipped with an EMS or other sensing monitor to detect the missing neutral-to-ground bond. But to be sure, I sent your question to my buddy and frequent FOG (Friends of Gary) contributor in the RV Doctor Newsletter, Mike Sokol. Here's Mike's response to your question:

John, as Gary has pointed out, RV electrical systems are wired with their Ground and Neutral buses floated (un-bonded from each other). There's lots of good reasons for this, but for now just accept that's how they're wired. Now, when you're plugged into power from a building (your garage outlet) or campground (pedestal outlet), your RV has its internal Ground and Neutral buses "bonded" (connected) together externally as part of the serivce panel's earthed safety ground system. Again, lots of reasons for this, but the fact is you can only have a single G-N bonding point according to the National Electrical Code and RVIA building codes. 

When your RV is powered by its on-board generator, this G-N bond connection is created by the transfer switch set to generator mode. But when the transfer switch is set to shore power, then your RV expects the external power source to bond its Ground and Neutral wires together. Now if you have an inline voltage monitor system from a manufacturer such as TRC, SurgeGuard or Progressive Industries, your voltage monitor is checking for the Neutral and Ground voltages to be very close to each other, probably within 3 volts or so. This works well if you're plugged into shore power that's properly grounded and bonded, but this voltage protector can be tripped off by plugging your RV shore power plug into a portable generator without an internal Ground-Neutral bond. If you don't have a voltage protection device (SurgeGuard) on your RV, then you may never know that your generator has a floated neutral (un-bonded G-N bus). 

Contractor-type generators such as your Coleman 5000 are most probably G-N bonded internally, which is why it runs your RV just fine. However, many portable inverter generators from companies such as Yamaha and Honda (your EU3000 specifically ) have floated Neutrals (no internal Ground-Neutral Bond) since they expect an external G-N bond to happen somewhere else. And while RV-approved generator have an internal G-N bond, but it seems that many of the most popular portable inverter generators from Honda and Yamaha have floating neutrals. I don't know if they're RV-Approved or not, but they don't have bonded G-N buses. Now I discussed this very point with Honda engineering last month, and they confirmed that their inverter generators have floated Neutrals and they simply say that you should follow all local electrical codes for bonding-grounding. So your EU3000 isn't providing a Ground-Neutral Bond that your RV requires to think it's getting properly grounded power, while your Coleman 5000 has a Ground-Neutral bond so it operates your RV properly. Seems crazy, but that appears to be the scenario.

It's pretty simple to wire a special "Ground-Neutral Bond" jumper cable for your Honda or Yamaha generator which will allow you to power your RV through its voltage protection device. You can obtain or make a dummy 15 or 20 amp "Edison" plug with the Neutral and Ground screws bonded together (see photos below). This jumper plug can be plugged into one of the generator's 20-amp outlets, and the entire generator will be N-G bonded. You can then use the other 20-amp Edison outlet or the 30-amp outlet to power the RV. It sounds like this would be a pretty good topic for a serious article on generator grounding and bonding, so stay tuned and the RV Doctor will likely post a link to that article here soon.  Mike