Single Phase Alternator Design

[bcavender]

A manufacturer rep made the comment to me that “All permanent magnet alternators are three phase.” And looking at several “single phase” alternator head configurations, they are connected zig-zag or double delta WITH kw/kva capacity reduced 30-45% to meet the single phase requirement.

I have puzzled for a while as to why some nature of single phase winding design could not be created rather than paying for a machine that is larger in size/cost than the application requires?

I suspect I have missed some key fact in my searches … or it is simply a matter of economics that there isn’t enough benefit or demand to design/support such a product.

Can someone that’s been around this rodeo before help me understand what I am missing or a proper place to learn the real scoop about this?

Thank You!

Best regards,
Bruce

 

[waross]

On the one hand, nothing is sure at an auction untilthe man with the hammer says;
"SOLD"
But
The 20kW sets don't seem to bring much more than the 6 kW and 8 kW sets at auction.
Ritchie's isn't the only game in town.
Check online for closer auctions.

A friend of mine got a sweetheart deal on a 6 kW set.
It was a few years old the output voltage dropped.
It had less than 500 hours on the meter.
It had very few hours but the outfit had other generators so it just sat in the back of the lot for more years.
Eventually they sold it to my friend for a couple of hundred dollars.
I changed out the capacitors and he has a good working, low hour set.
The cost of capacitors?
A few years ago, there was a government program encouraging a change to LED lighting.
A lot of small town arenas changed over.
From time to time, you can see a pile of "take-out" 400 W discharge ballasts out behind an arena.
I had cleaned out a garage on the basis of;
"Take everything".
I now have about 90 old ballasts out back. A few of them are missing the capacitors.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[bcavender]

LOL … I hear you.

A little knowledge down at the nitty gritty goes a very long way.

Back when I was just starting, I needed a van to carry tools and work out of, but had little cash. Most vans were $12-16k. I found one for $1500 that was only 3 yo. Salesman told me the valves were wrecked and their mechanics said ‘new engine’. I had a 318 engine before and it was solid as a rock. I thought OK I’ll bite for the engine because I had time and no money.

I got it back at the house backfiring like crazy. So I was amazed that a compression gage showed all cylinder pressures were in spec!

Scratch, scratch.

Wires were great, coil snapping fine … so I pulled the distributor cap and found a burned carbon track between two studs!

I scraped it down to Bakelite and the engine smoothed out perfectly. I was a happy camper LOL.

 

[waross]

Are there any Jimmy diesel guys left?
A friend of mine was responsible for maintenance at a residential school.
The backup generator had quit. It would barely run and blew clouds of black smoke.
A mechanic had diagnosed it as a complete engine failure and recommended a new gen-set.
If the authorities became aware of the situation the school would be closed and evacuated. There were implications of pollution of a recreational lake if the sewage pumps were out of service.
I reset the intake flap valve and the set ran for more years.
The old 71 series Detroit Diesel engines had a habit of running away if an oil seal in the blower failed and lube oil got into the ait intake.
A common feature was a flap valve in the intake manifold to stop the engine in the event of a runaway.


--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[bcavender]

Never heard of an intake flap valve, but most of my work has not been diesel.
I can see how it clamps down in the case of high flow. Clever. Learned something.

 

[waross]

The Detroit Diesel or Jimmies had the flap valve latched open. The latch may be released manually, either directly or electrically. or automatically, either electrically or mechanically.
The intake flaps were standard equipment on most 71 series Jimmies.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!