Sunday, June 26, 2016

Wind generator repair

The crane is back. My grandson, Gus would love it! It has been 11 years since I put the Enertech 1800 up. Thanks Mick Sigrillo. Now because of a crack in the mounting plate I brought it down.

Working on the top of a 50 foot tower is... lets say exciting. When you have to let go and use both hands on something putting all your trust in a thin strap of nylon and a couple of clips!

The the wind was low (about 5 mph) and since there is no good way to lock the yaw of the head I was at the mercy of the wind to hook the crane to the generator lifting eye screw. Finally I made the hook and removed the nuts so the head could be lifted. Unfortunately as luck would have it the balance was off and the mounting plate jammed on the bolt threads. With nothing to lever with or against I decided to screw the nuts below the mounting plate up and raise the head to the top of the three bolts. Problem solved.

For years I have had a family of birds nesting in the nacel. Each year I would evict them and each year they would come back. Looks like this year they really did a number on some of the wiring. One of my repairs will be to bird proof the unit!

OK. Now now a new project. Let the learning begin.

Monday, June 20, 2016

Yeks! This is trouble...

Last January I hear this strange clicking noise outside and wondered if it could be my wind generator. Shutting off the generator stopped the clicking noise. Not wanting to test fate I shut it off until warmer weather. When I climbed up to have a look this is what I saw. Yeks! A crack in the mounting plate. Had this broken off I would not need a crane to take it down for repair. Gravity would have done the job for me.

My guess is that the designers got it wrong when they drilled that 1" hole in the plate for the power cord. This weakened this section and after many years of flexing caused a metal fatigue crack. My repair will be to make another plate and weld it to the existing one. I will make some other arrangement for securing the power cord in place. More pictures to follow when I get the crane in and take the unite down.

In my last post I had just repaired my SDHW system and replaced the anti-freeze in the hot loop. Then it was time to replace the pipe insulation on the roof lines. I had good weather and everything was going just fine. I should have known.

As I removed the insulation around one of the high point vents I noticed some corrosion. 

Upon removal and close examination I realized that when they say that the anti freeze should not be used with galvanized fittings they mean it. In this picture you can see the brass fitting below the other vent is just fine. So I had to drain off some of the loop, replace the fitting and then refill and vent the system. Oh well live and learn it guess.

Thursday, June 9, 2016

Solar hot water system mantenance

        Installed in August of 2005 my SDHW system has been a learning experience. After storing 2 salvaged flat plate collectors from a 1970's system and reading up on several system designs in Home Power magazine I made the leap. After building a tube within a tube heat exchanger that was featured in Home Power I was ready to go. Second, I say second because it took me two times to learn that the domestic side water loop would require a bronze circulating pump to survive the high lime content in my non  softened water supply. Then everything ran like clockwork and provided over 50% of my hot water needs (100% during the summer months)for the next 10 years.
       Year after year all was well until around November of 2015 and I noticed that the system was not pumping. Thinking that the problem was with the anti freeze filled solar loop I did not want to mess with this until warmer spring weather. So I waited until last week. Then I noticed that there was a small black burn mark on the circuit board where a relay for the differential temperature controller was. After replacing the relay still no go. Now I had the problem zeroed in as a locked pump that allowed high current to fry the relay. The plan was to replace the hot side loop antifreeze side and pump.

After draining the system I was ready to replace the pump and refill however the pump was just fine.
So I want ahead and refilled the system and bled off any trapped air. So far so good.

Now would have been a good time. I was a bit fuzzy on remembering the system details and how all the pieces, pumps, check valves, loops, air vents expansion tanks, etc, etc. fit and work together. But, I plunged ahead. Shutting off the water supply and removed the domestic loop pump. Locked solid just as I suspected. Even the bronze pump could only last 10 years.
Here is where things got ugly. The picture shows the correct stack up with the compression plate behind the pump cartridge flange. For some odd reason on the first try I put it on the other side. A total failure to seal the water and when I turned on the main, in the basement, water shot out all over before I got upstairs! And back down!! I had a lot of time while cleaning up the spillage to THINK!

After replacing the pump cartridge with a new bronze one I also installed a flow indicator in the domestic side. There is just something about seeing the flow in the system that gives me piece of mind.

And in a few short minutes of operation the pressure was up and the solar loop was hot. That heat was being transferred by the heat exchanger to the domestic water. There would be a solar shower tonight!