Daily Archives: October 28, 2014
Same Old, same old . . .
Trucks come in. Trucks go out.
The frack equipment continues to move in, but so far it seems at a slower pace than our other fracks. But that may be just the calm before the storm, so to speak. We’ll see. At least we probably won’t have two fracks going on at the same time like before.
Maybe.
One of our RV friends has been having a problem with small floor heaters in their rig burning out after a few days. So she asked me for help, and although I haven’t heard back from her yet, I thought I’d pass on my ideas.
The RV is on shore power plugged into their garage, and everything else is fine. But so far 3 of these small Lasko-type floor heaters have burned out within a few days when plugged into the rig, after working fine in the house.
After thinking on it a bit, my thought is that even though she’s plugged into shore power, that outlet, or all of them, must be coming off the inverter. I guess it depends on how your transfer switch is wired up.
On our rig, if we’re on shore power, the inverter is not in use, even if turned on. The order seems to be: Generator, Shore Power, Inverter. But I’m wondering if her rig might have a different order.
I suggested she check to see if her inverter is on, and if so, turn it off. Then check to see if that outlet still has power. Now she knows she’s really on shore power. And I suspect that she won’t have anymore heater problems.
The reason I think her inverter is involved is that a lot of electronic equipment does not like the modified sine wave power put out by most RV inverters. This graphic from the Xantrex company shows the difference.
The red line is what the power coming out of your wall outlet at home looks like. The blue line is what the power coming out of most RV inverters looks like. A big difference. And a difference that a lot of electronics doesn’t like. It just depends on how it’s designed.
In our case, a few years ago it happened to us. We have a heated mattress pad on our bed and it has dual electronic pushbutton controls. One day while we were traveling, and had the inverter on, one of the controllers fell off the end table and turned on when it hit the floor. This immediately killed it. Luckily I was able to order a new one. And now we unplug the mattress pad when we travel.
Most computers will work OK, and most devices that use ‘wall wart’ power supplies, or inline power supplies like laptops, will also work OK. Usually if it has a transformer in the power supply, it will work.
But it seems like any device that involves large current draw, heaters, coffee makers, etc., and has a digital readout/controller, is going to have problems with modified sine wave power. I won’t go into why this is circuit-wise, and the fact that the circuit could easily be designed not to have this problem, but it would cost an extra dollar or so. Of course if you’re making a million heaters a year, this adds up, so there is that view of things.
There are several things you can do here. First, check the literature that came with the device. In many cases it will say, “Not For Use In An RV”. Second, call the manufacturer or check their website.
Finally, if all else fails, buy something cheap. Get a heater that just has a knob that says, “OFF, HI, MED, LO”. It will work fine. Same goes for a coffee maker like that.
Or you could just replace your rig’s inverter with a $2000 Full Sine-wave model. Yeah, that’s the ticket.
That’s probably about enough on the tech stuff. Many of you are dozing off already. Jan says you can ask me what time it is, and I’ll start with the history of the sundial and come forward from there.
She’s probably right.
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Thought for the Day:
If my words offend you, you probably don’t understand sarcasm or criticism . . . or you do.
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