We took our daughter and grandkids on a road trip to visit our son (and new wife) in Houston last month. Along the way, we encountered 2 interesting problems with Lucy, a 2009 Lazy Daze Mid Bath motorhome. One problem was with the airconditioner, which was much needed on this trip, and the other with the automatic transfer switch, which is also know as a line-generator switch. I wrote up the situation while it was occurring, so I'll just cut and paste that in now.
July 21, 2015
Air conditioner and ATS difficulties on
trip
Air Conditioner
Problem: Water dripping into motorhome
while parked and air conditioner running.
The amount of water was not a lot,
maybe a tablespoon or 2. It usually dripped from either the lowest
point of the inside shroud or the passenger side air inlet area
(which, because of being slightly out of level was probably the
lowest point). The first occurrence was after a heavy downpour at Gulf
Shores AL. That implies that the gasket seal of the roof air
conditioner was possibly a little loose, so, the inside shroud was
removed and the 4 “holding” bolts were tightened slightly, not
over a ¼ turn. (Shroud is removed by taking out 8 phillips head
screws.) Shroud replaced and on we go about our business. Next day,
which was sunny, same problem. Hmmmm. Now it sounds like the drain
pan may be stopped up. On to the roof, tools in hand. Outside shroud
is removed by removing 6 phillips head screws. At this point, it should
be noted that the outside portion is mounted on 4 rubber feet, which
maintains about a ½ inch gap between the bottom of the outside
portion of the A/C and the roof. This is necessary to allow the water
in the drain pan to flow out from under the outside A/C. With the
shroud off, there are 2 radiator coils needed for operation of any
A/C. The one at the rear (stern, if you will) of the motorhome is the
condenser coil, and is the “outside unit” that you see if you
have a home A/C built into your furnace. Technically, this is called
a “split” unit, because the condenser coil is outside and the
evaporator coil is inside in your furnace. On our rooftop A/C, the
condenser coil is visible, and forward of that, with the motor in
between, is an enclosed “box” containing the “inside” unit,
which, by now you should know is the evaporator coil. It's this coil
that removes the heat from inside air, or said another way, it
provides the cool air when the A/C is running. To see this coil, and
get to the drip pan, we need to remove the 5/16 inch hex head screws
on the cover. There's probably 15 or so of them. Then carefully
remove the cover: it's sealed to the surrounding metal to separate
the cool air from the outside air. The drain pan is toward the rear
of the coil (nearer the motor), and has 2 plastic outlets on either
side of the pan to let the water out. Take a cup of water up, and
pour it over the coil or into the pan to be sure the outlets are free
flowing. If you have a soft brush, like a paint brush, you can also
clean the dirt off of the evaporator coil while you are there. It
would be a good idea to do the same for the condenser coil as well.
Be aware that the fins on the coils are sharp enough to cut, so watch
those fingers. OK, now I'm sure the coils are clean, the drain pan is
not stopped up, the gasket is tight, the unit has a ½ inch gap under
it, I've removed the wasp and dirt dobber nests (oh yeah, I forgot to
tell you to watch out for those; sorry), everything is back together
and, drum roll please, it still does the same thing. So what's wrong
now?! Actually, I think, nothing. Take a step back and look at the
big picture. I'm on the gulf coast in July. That means temps in the
90 to 100 range, and humidity levels in the 80 to 90% range. A/C is
going to run most of the time, and put out some quite cold air after
a while. We also have 5 of us in the motorhome: wife and I, our
daughter, and 2 grandkids (4 and 5). That's a lot of water vapor to
pull out of the
motorhome, and while the A/C is in the process of taking out the
water vapor, there is always some left in the inside. I think that
when the very cold air is hitting the plastic inside shroud, water vapor is
condensing on it and THAT is the cause of the tablespoon or so of
liquid water that I see dripping inside the motorhome. The fix? Twofold, in this case. 1) That fan moves a lot of air, so I also check the filters, which really
don't look very dirty. Oops; when I clean them under running water, they
start to look a lot cleaner. 2) Move
to a less humid place for a while, which is what we did. No more
drips. Well, my wife still thinks I'm kind of a drip, but that's
another story. So, the final answer was basically, make
sure the filters are squeaky clean when in a very hot and humid
environment, like the Gulf Coast in mid July, and expect the possibility of a little condensation while in that environment.
ATS, or Automatic Transfer Switch, or
Line Generator Switch.
So, with 90+ degree temps and 1000%
humidity, you might think having a good A/C might be a good thing. So
do I. As we go driving down the highway, we decide to turn on the
roof A/C as well as the dash A/C to help with the massive heat build
up. Ok, so everything is going along fine until we notice the roof
A/C is off. Generator is still running, so it will come back on in a
minute. Nope. A few minutes more. Nope. “Joyce, go look at the
(Progressive Industries) surge protector and be sure the light are
blinking,” I say. No lights. Hmmmm.... Better check this out. Why
is the generator running and the surge protector off? Well, we park
for the next few nights, plug in to 120V on the post, look at the
surge protector and pray. Everything appears to be working. So,
what's going on with the generator? Last year, the power generating
part of it was replaced after it self destructed, (at about ½ the
cost of a new generator, ouch!), so what did the generator guy miss?
Now the troubleshooting begins. Kids at the beach, so wife and I pull
the power panel out to look at the input of the ATS, which is a lot
easier than trying to measure the output of the generator AT the
generator. I should note at this point, if you haven't already
figured it out, I fed the output of the transfer switch to the surge
protector, which protects me from a problem from either the post OR
the generator. OK, generator running, voltmeter/frequency meter
plugged into an outlet, A/C and refrig on, just like when driving. Of
course, with the A/C running, I'm going to know when the power cuts
off, but not if the reason is a change in frequency (from 60 Hz),
that the surge protector will stop the current from flowing for.
Well, 40 minutes later, everything is just fine, thank you m'am, of
course. Lets start unloading the generator and cut it off. Refrig,
off. A/C off. Power, off. What? No change in the voltage or the
frequency of the generator showed up before everything went dark.
Generator is still running, and if you have had generator problems,
you know that if it's still running, it's making power. Let's see,
input to ATS from generator, fine. Output. Hmmm..... Black to White
(hot to neutral) no volts. That explains no A/C. Ground to hot
(black wire), 120V. ??? Ground to neutral, 75 volts? What's going on
here? Well, it appears I have an intermittantly failing transfer
relay that switching only one of the two wires that it needs to
switch. I guess I'll know today, when the new one arrives, hopefully.
Now, for the rest of the story. It's been about 2 weeks since I wrote the previous paragraphs. No more leaks from the air conditioner and the problem was the ATS. The new one has worked just fine, thank you. Had roof A/C all the way home, which was good.
Now, if only the clouds will part, I hope to catch a few photons. It's been so long since I've been in the observatory, I'm not sure I remember how things work. Oh,well. That's why I make notes. If I can just find them.....
