Boy, did we ever get an earful.
"This 'solution' is more of a money maker for the seller than anything else," said one reader. Others raised many technical concerns, indicating that in practical terms, the device wouldn't really do what RVers wanted it to. We took those concerns to Camco and asked for their comments. It took a while, but finally, Jeff Russell, one of the company's mechanical engineers, returned our call and settled in for a chat about the device.
Rusell admitted that the concept of plugging into two different outlets on the same power pedestal wasn't new; it's just Camco had concerns about overloading an RV's neutral wire, and so that was the reason they designed it to pull a 30 amp leg and a 15 amp leg, the thinking that the combined 45 amp maximum draw wouldn't overload the neutral. And yes, the system isn't designed to provide 240 volts, but rather simply 120--so if your RV's power management system looks to "see" 240 volts, it won't work for you.
Are there power "limitations," we asked? Could you really draw 45 amps? The answer was a "yes and no," situation. You could conceivably pull 45 amps--provided the power loads in your RV were on the correct power legs. For example, if your air conditioner is wired on what the PowerMaximizer "sees" as the 30 amp leg, well and good. But if your air conditioner winds up being wired on the 15 amp leg, you can easily expect to pop the breaker on the RV park pedestal. Of course, the real trouble is, there's really no way of knowing which leg is which. And yes, says Camco's Russell, the RV with a 50-amp service typically can draw 100 amps--two 120 volt legs of 50 amps each. As a result, the "Maximizer's" 45 amps is going to be a pretty paltry supply. But Camco argues it's better than 30 amps provided through a "dogbone" adapter.
Of course, if the RV park you land in has Ground Fault Interrupters in the RV outlet box, you are really dead in the water--the system simply won't work at all. You'll forgive us, dear reader, as the number of times we end up in a commercial RV park in a decade can probably be counted on the fingers of one hand. We haven't surveyed just how many parks have GFIs--but by your experiences as related from your comments, it's as one reader said, "That means this device will normally be dead weight in the storage box."
We appreciate your feedback, and the opportunity to give Camco a shot at responding to your thinking. We look forward--maybe with a teesny bit of trepidation--to your next salvo!
Thanks to suneko on flickr for the "shout" photo
4 comments:
This isn't about the gadget, but about the colors you are using in your header - the links for RV and GADGETS are in an unreadable red on grey. This is a rookie mistake - it might be that you haven't seen this on a laptop's lcd screen that you weren't aware of the issue - if the blogger template won't let you customize the foreground color, and you love the background color, then get rid of those two links - I almost couldn't get past the header when I landed on this link and you really don't want to turn people awawy - and by the way,it's a nice design, otherwise. AND on the subject of the power system, I know it's been mentioned, but I suspect it's not been explained so non-engineers get it - with a 50 amp service, there are two legs on different phases - the alternating current "waves" are such that when one goes up, the other goes down. That means that if you have one of the two 50 amp sides drawing it's full load, the hot and neutral wires are both carrying 50 amps, which they are sized to do. If you then turn on 50 amps on the other leg, the other hot wire starts drawing 50 amps, but it sends it's return current to the neutral wire, but always going the opposite way - the neutral now carries zero amps even though the coach is using 100 amps total. If they were on the same phase, each hot wire would carry 50 amps and the neutral would carry 100 amps! So with the cheater, if the 30 amp and 15 amp are on the same phase (leg of the breaker box) then fully loaded, the neutral would carry 45 amps...
I bought one of those devices over 3 years ago. Every time I tried to use it the pedestal had a GFCI style 15 amp socket. The device tripped the GFCI every single time. I have never been able to use it, not once. I imagine the electical code is pretty darn universal about GFCI sockets on an outside recepticle. It was a really nice concept but it fails miserably in execution.
Some while ago I built one of these for myself. I made it with two 30 amp connectors so that I could use an adaptor to go to 15/20 amp if I needed. There is nothing in my class A which needs 240 volts so two 120 volt feeds work well. I did mark the connector which goes to the rear of the rv since it seems to be more lightly loaded. I have often used two 30 amp feeds, but check for ground differential before using.
My rv has a 7.5kw gen which will run everything. This works out to 62.5 amps total available, which is close enough to to 2 30 amp feeds. For my plugin at home I put in a 50 amp connector wired and with breakers for 30 amps and have never tripped one.
I opted for a 30-amp version of the portable Hughes Auto Former; I've used it on both 15a and 30a input circuits to boost the voltage (and reducing amps/heat) to my 50a 5th wheel.
At campgrounds with only 30a socket, it allows me to run both A/C's without over-heating or tripping breakers; at my son's house, on 15a circuit, it allows me to run large LCD TV and one A/C with no problem!
Sure has been a helpful tool so we can run 1 or 2 A/C's plus normal, small appliances under those conditons! BTW, it also filters out some of the noise that "bothered" my EMS in several occasions where the park/house power was marginal.
-Don France
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