A little electrical work

I have a love-hate relationship with the air conditioner on top of my van.

Because of the length of my commute, for the last ten years of my working life I lived in my van during the work week. Monday morning I would roll up before dawn and park out behind the office, then stay right there until the weekend. Since this office was in Houston TX, for 3 month out of the year the AC was survival equipment and well loved, though also despised for the constant noise.

But I'm retired now and if I had my druthers I'd pull that damn thing, noisy, heavy and a general pain in the ass, off the roof. But it's still there, primarily because I keep finding myself heading out in the worst of the summer for obligatory trips. (Family! What can you do??)

Needless to say, since my retirement that AC up there on the roof doesn't get used unless absolutely necessary, so it sits idle for the vast majority of the time. And that creates its own problems because around here we're blessed with an abundance of mud daubers. They're everywhere and get into everything, so I've learned that before heading out on a summer trip where I might need it, I have to climb up on the roof, pull the cover off the neglected AC and hose it down thoroughly. I was taught this lesson one sweltering afternoon when I couldn't take it any more, closed the windows, shut the vent, and turned the AC on for some blessed relief, only to have it nearly jump right off the roof! Daubers had built a rather large nest on the fan blades, a nest that probably weighted nearly as much as the carefully balanced blades, which weren't so carefully balanced anymore.

Since I have one of those summer trips looming, the other day I got the ladder out and drug the hose around from the other side of the barn. After wrestling the cover off the AC and getting it safely down to the ground without breaking it or myself, I climbed back up and proceeded to send mud and larvae and paralyzed spiders (Larvae food.) flying everywhere with blasts from the hose. After spitting out the mud and picking bug bits from my teeth I buttoned the AC back up, plugged into shore power, and turned it on.

Another lesson learned through experience: never trust that something is going to work simply because it worked last time you tried it.

With the AC running smoothly and producing cold air, I set the timer on my phone for 10 minutes to remind me to come back and check on it. I did, and so far so good. This time I set the timer for 20 minutes to make sure I gave the AC a good workout. By the time the timer went off again I had moved onto other things and completely forgotten I'd left the AC running (Very handy things, smart phones with stopwatch/timer apps! Now if only I could remember why I set the timer. . .) When I went to check on it it wasn't; wasn't running that is; you know, the AC

Since I had turned the thermostat down as low as it would go and I was pretty sure it wasn't anywhere near 40 degrees in the van yet, I knew the AC hadn't simply cycled off and that knowledge made my heart drop. A quick check of the basics turned up the 20 amp breaker feeding the AC as the culprit. It had tripped.

OK, this is not good! Summer trip + persnickety AC = potential misery (My niece's wedding was in the middle of summer years ago, and though it was far to the north in Michigan, it was a week of muggy, 100 degree days! Days the family still talks about.)

When I went to reset the breaker in one of those 'hail Mary, please let this be a one-time glitch' moves, I burned the whorls right off my finger!

Son of a - - -! (OK, let's just pretend I said gun. . .)

Where's the guy that cleans the camera lens when you need him?!  Oh, yeah, that's me. . .

As should always be the case, my electrical panel is easily accessible and at eye level, but it is compact with only 5 breaker slots and one of those is taken up by the main input breaker. Now-days four branch circuits is not enough for all the equipment packed into some of the fancier RV's, so the solution is to use paired breakers so you can get two branch circuits into a single breaker space. This way the smallish panel can support up to nine branch circuits, each with their own proper over-current protection. The down side is that most standard breakers are thermal devices and now you have two of them jammed cheek-by-jowl in the same case and when it's already hot, huddling up is not the best strategy for staying cool.

A paired breaker set within a single breaker case. This is the 30 amp main input and the 20 amp that feeds the AC. These paired breakers are handy when panel slots are limited, but I'm not a fan of them.

In addition to high current, loose wires are also a pretty good way of generating a lot of heat. In fact loose wires manage to start a whole bunch of fires every year. So I disconnected from shore power, shut the 12 Volt power off near the battery (Like many RV electrical panels both the 120V AC and 12V DC are in the same panel.) and pulled the cover.

I forgot to take a before picture so you have to imagine that originally the panel was populated by only the two sets of paired breakers at the top.

I was delusionaly optimistic that I would find a loose connection going into either the 20 amp AC breaker or the 30 amp input breaker that shared the same case. (The top set in the photo above.)

Of course, as is usually the case, delusion slapped me in the face and both connections were properly tight; exceedingly tight, beyond all hope of generating any extra heat tight.

On to plan B: (Plan A was to cancel the trip but I figured that wouldn't go down very well with a lot of people. . .)

To test the 30 amp half of the breaker pair, which is the main input breaker, I plugged in two electric space heaters. One into the 15 amp GFI branch and a second into the 15 amp Microwave branch, and set them to running. As long as I kept both heaters on low their combined draw would be about the same as the AC when it's running and, more importantly for my purposes, all the combined juice running through the two 15 amp breakers also has to funnel through the 30amp input breaker as well.

Again, I reverted to my handy timer and when I came back after giving everything time to cook up nicely, not only were the heaters still running but the 30 amp breaker was just barely warm to the touch. This told me that the internals of the 20 amp side of the paired breaker is where the heat was coming from. (Yes, it could still be that the innards of the AC itself were at fault and were drawing too much current, but that's more of a terminal condition and I wasn't going to go there, so was doing my best impression of an Ostrich. . .)

Fortunately my van is not very complicated so I don't need a plethora of branch circuits, which leaves some extra slots in my panel. Unfortunately, searching through my electrical tub, you know, where you throw everything even remotely electrical related, turned up a spare HOM style breaker, which is what my panel takes, but it was a 30 amp, not the 20 I needed. A second search, dumping the tub out onto the floor this time, didn't do any good. All I had was the 30.

But, just to test my findings, I installed it in one of the empty panel slots anyway and removed the AC wire from the suspected faulty 20 amp breaker and connected into the new, but dangerously over-sized 30 amp breaker, then turned the AC on for another test.

Now listen up! This is how homes and vans burn down! So as a general practice, this is not something I would recommend doing!!!

Which is why I didn't need to set my timer this time, because I wasn't about to leave things running in this state without direct supervision. Improperly protected electricity is a lot like having a 2-year old running around a workshop full of chokey bits and things that cut; you can't take your eyes off the little creature for a second. So instead I grabbed a book from my ready stash and settled into my chair in the van for a half hour of vigilant reading.

Everything held! The AC ran continuously and the breakers, all of them, not only stayed set but also cool.

The next day I had to make the 18 mile, back roads run over to the art gallery my friend owns. (Yes, my only friend, you don't have to rub it in!) The gallery is in a town with the whopping population of 90 (89 actually, since the lady living next door to the gallery died during the week.) and, like our place, is about 20 miles from the nearest shopping district. But this little town does have a mercantile, a true mercantile where you can buy gas, animal feed, tractor parts, cereal, clothes, and just about anything else you really need, including a 20 amp HOM style breaker.

Yep, same photo again. This time, if you look close you can see that there is no longer a wire going into the 20 amp breaker second from the top. That's because that wire, which goes to the AC, is now attached to the new, full sized 20 amp breaker at the bottom of the stack. The original, and faulty, 20 amp breaker goes to nothing now so won't be causing anymore problems. (OK, I'm back. Had to go find some emergency wood to knock on.)

So for $3.50 I bought a new, properly sized, breaker, installed it, crudely relabeled the panel, prettied everything back up, and now, AC wise, I'm all set again.

Again that dirty lens got me, (One day I'll learn that no matter how much I hope they will, things like that just don't seem to fix themselves.) but here's the panel all buttoned back up with my new, full sized 20 amp breaker there at the bottom of the stack. The only thing left to do now is put the beauty cover put back on. Notice that I have far more 12V circuits than 120V and that's the way it should be for a mobile domicile with solar on the roof. In fact, the 120V breakers are all turned off in this photo and that's the way they stay most of the time.