Time for generators

[ajaffa1]

G`Day Guys and Gals, not much to report, had to spend my day sowing grass seed as we have a wet weather event coming our way.
I did however, find the time yesterday to clean up and test the three phase transformer pack, everything tests OK, cleaned and varnished as per photos. This is a very simple set of transformers that regulates the generator output. All of the load on the generator runs through the 3 large transformer windings, this produces a voltage in the 3 windings on the other side of transformer which are rectified and fed to the field windings. As the load increases so does the voltage being fed to the field windings to compensate for the increased load. This should be a very stable generator so I doubt I will be worrying about an AVR.
Couple of pics attached.

Bob

[broncodriver99]

Looking like new. Nicely done.

You're going to have to give a shop tour one day. I follow a guy on youtube who just finished up a shop/off grid house build somewhere in the outback. His building kit looks very similar to what I can see of yours in the background. I remember thinking it was very nicely made and assembled very easily. Nothing like the kits we have in the US.

[ajaffa1]

Hi Broncodriver. I did post some pics to the LEF while the shed was being built. The shed measures 13m long by 12m wide with two outdoor covered parking spaces and is fully insulated. All up, including concrete slab, 200 tonnes of road base, electrics, plumbing, landscaping and water tanks this cost A$90,000 just shy of $60,000 US.
A couple of pics attached, sorry about the mess, I`m too busy to tidy up! 

Bob

[ajaffa1]

G`Day Guys and Girls, so having had two wet days I have been able to concentrate on the generator head. The armature is back in place and both bearing houses have been fitted. I popped out the bearing seals at each end and applied a little fresh grease before assembly.
I cleaned the four slip rings with a scourer pad and they look fine, no sign of wear. I spent a lot of time and effort cleaning the brush assemblies, they came out real nice. The brushes look good, one very small chip on one brush, I don`t think it will ever be a problem.
Pics attached.

Bob

[ajaffa1]

Sorry, forgot to post pics of the brush assemblies

Bob

[ajaffa1]

G`Day again. Having fitted the brush holders and adjusted them, I decided I was on a roll so I refitted the transformer pack and pulled the wiring back into place. I then took a look at the radio suppression assembly and replaced the four buggered capacitors with new ones. The replacements are smaller than the originals but are rated the same, should be OK. Once these were fitted I powered up my multimeter and  checked the outputs between the neutral slip ring and three others. Just spinning the armature by hand produced 0.1 volt AC from each phase, very happy as it looks like there is enough residual magnetism left for this to re-energise itself without having to flash the field windings.
Pics attached.

Bob

[dax021]

Looking great Bob.  I wish I had your skills

[ajaffa1]

Hi Dax021, thanks for the compliment. No great skills involved in this, mostly time, patience and elbow grease. The ability to use a soldering iron helps. Taking lots of photos before and during disassembly helps a lot when it comes to reassembling stuff, especially when you get to my time of life and the memory isn`t what it was. I am a huge fan of electrical heat shrink , very often the original cable identification tags/colours have disappeared, fallen off or become illegible. a dollars worth of different colour heat shrink during disassembly will save you hours of aggravation later.

Bob

[BruceM]

Fantastic work.  I love that old tech three phase head. Readily maintainable, reliable.

I applaud the shrink tube color coding.  I have also found that banding with label maker tape- sometimes with a tab for text has held up very well and makes future repairs easier.  The aggressive acrylic adhesive stays secure, so far for 10 years plus.  I can get 4 lines of text on the 1/2 inch wide yellow tape. No other tape has been able to do that, thus my appreciation for colored shrink tube where the color codes can be added to the wiring diagram.   I am trying to do much better on documentation for my tech projects due to failing memory. 

Thanks for sharing your outstanding work!
Bruce

[ajaffa1]

Thank you Bruce for your kind words. Yes, this unit is a very nice reliable old girl which will probably still be going long after I am gone. Once it is running I will have to write an idiot proof instruction manual explaining how to start/stop it, maintain it and switch the house over to run off it.

Over the last few days I stripped, cleaned and painted the drive coupling. This is a nice unit and has had a good dose of O ring grease applied to the rubbers, that make up the coupling before fitting. I spent a lot of time buggering about to get the coupling as well aligned as humanly possible, a few shims made from damp coursing and it is as good as I can get it. There is a 10 thou gap between the two halves of the drive coupling and this gap only moves by 1 thousands of an inch as I rotate it. Not perfect but as good as I can get it.
A fresh coat of Brunswick green and it should last for years. pics attached.

Bob

[ajaffa1]

G`Day again, my next job is to strip paint and service this control panel, I hate electrical work.

Bob

[BruceM]

The internal wiring appears first rate.  Pity you have to mess with it.  It will be a chore to document well enough to remove and reinstall.  I hope the PVC wire insulation is still in good shape so you won't have to rebuild the wiring harness as well.

[ajaffa1]

Hi BruceM, I`m hoping the wiring insulation is going to be OK. There are four things that PVC hates: time, hydrocarbons, heat and rodents.
This was made in 1976 so it`s old enough for time to have taken it`s toll. I had to replace a lot of exposed PVC cabling around the engine.
There was a leaking diesel fuel line that some idiot tried to fix with a pipe clip rather than replace the rubber fuel line, so the entire unit was covered with diesel that had dried into a nasty sticky varnish. This was previously owned by the New South Wales State Emergency Services, a hot day up there would be 50+ centigrade in the shade, plenty of opportunity for PVC to degrade. I did dig a few mouse nests out of the sound proofing but haven`t seen any eaten cabling yet.
I have lived through one mouse plage and seen the damage these little buggers can cause, just as an example; they tried to get into my chest freezer, they could not get in through the top because I had loaded it with concrete building blocks. Didn`t stop them from eating all the wiring and insulation underneath the unit! They also ate the rubber water pipes on my Wife's car, luckily we only took a short journey and didn`t seize the engine.
I`ll let you guys know how it goes.

Bob