Transformer for your rig?

[KA5PIU]

Hello.

Went down to the electric utility bone yard to see if I could get a transformer.
I selected the smallest pole pig I could find as well as several extra feed through insulators.
What I selected was a 2400VAC dual winding multi-tap primary with 110-220 secondary, rotary tap selector and circuit breaker.
Rusted outside but intact and operational.
210 pounds of beast!
I also picked up a 440/880 to 110-220 secondary 500 watt dry transformer, a 2 primary windings unit that is connected series or parallel as needed.
The pole pig, likewise, has 2 primary windings but this is internal.
I did drain all the oil out prior to leaving the yard.
New project!

[NQ6U]

http://i815.photobucket.com/albums/zz79/gyrogeerloose/WART-hog.png

[KA5PIU]

Hello.

And to add.
By the electric bone yard, what I refer to is the scrap yard.
Transformers are drained of oil and PCBs are contained if needed.
Although a transformer may still be operational it may get red tagged if it has some trouble, and off to the boneyard and to recycling.
The utility will not sell you a transformer due to liability but scrap is not a problem, and much cheaper anyway. ;)
I just priced 30 gallons of mineral oil!
All of the insulators are good as well as all of the switches and contacts I brought home.
I will clean everything up, may or may not use the pole pig wet, the housing is rusted but solid.

[KC2UGV]

Hello.

And to add.
By the electric bone yard, what I refer to is the scrap yard.
Transformers are drained of oil and PCBs are contained if needed.
Although a transformer may still be operational it may get red tagged if it has some trouble, and off to the boneyard and to recycling.
The utility will not sell you a transformer due to liability but scrap is not a problem, and much cheaper anyway. ;)
I just priced 30 gallons of mineral oil!
All of the insulators are good as well as all of the switches and contacts I brought home.
I will clean everything up, may or may not use the pole pig wet, the housing is rusted but solid.

If you get in good with the guys working on the power line, they might give you some for nothing :P

[KA5PIU]

Hello.

Yes, that is what I hear. ;)
I paid nothing for what I got. ;)
I was out at the scrap yard one day and they could not get their telephone working, landline.
I found the trouble, fixed it.
Next time I came I rewired it properly, added an extension ringer, added an extension, and ran a drop to the guard shack.
I also replaced the defective outlet to the window unit on another visit.
In short, I am golden there.

[KC2UGV]

Hello.

Yes, that is what I hear. ;)
I paid nothing for what I got. ;)
I was out at the scrap yard one day and they could not get their telephone working, landline.
I found the trouble, fixed it.
Next time I came I rewired it properly, added an extension ringer, added an extension, and ran a drop to the guard shack.
I also replaced the defective outlet to the window unit on another visit.
In short, I am golden there.

I was talking about the oil :)

[WØTKX]

That transformer is gonna make a great spark-gap transmitter, eh? :lol:

[W5GA]

Transformers are drained of oil and PCBs are contained if needed.
How do you do that? Do the PCB's fall out of the oil on the ground or something?

[KA5PIU]

Hello.

They have tanks that the PCB oil is put in that in its own area.
Otherwise, being mineral oil, it is incinerated.

[kb2vxa]

If you're actually going to use that beast you really should fill it with highly refined mineral oil intended for use as transformer oil. Dry, two things can happen, without cooling in an enclosed can the guts can overheat and the insulation break down in time if it doesn't arc over immediately. Let them laugh, the AM Gangstas have used them successfully but you'll need another matched and phased with the first to make a proper full wave rectifier for your plate supply.

[KA5PIU]

If you're actually going to use that beast you really should fill it with highly refined mineral oil intended for use as transformer oil. Dry, two things can happen, without cooling in an enclosed can the guts can overheat and the insulation break down in time if it doesn't arc over immediately. Let them laugh, the AM Gangstas have used them successfully but you'll need another matched and phased with the first to make a proper full wave rectifier for your plate supply.

Hello.

First, you can run them dry, this one is rated for 100 amp service, way over anything I will ever do.
Second, this thing has 2 primary windings in series and a tap changer set for 2200 volts hi line.
If I reverse the process I have two 1100 volt windings, 1100 volts DC full wave from two microwave oven diodes.
But I do have all the parts needed to add all of the connections to the tank make it the power supply in and of itself.
Since this unit has the circuit breaker and tap changer, the housing is quite a bit bigger, large enough to put capacitors inside the tank with ease.
I will need to complete disassembly, sandblast and repaint, and reassemble it.
This should take about 2 months, no hurry.
Having this large (huge) can next to a transmitter does not sound that appealing.
But, this will be a really nice Tesla coil and transmitter when completed.
2 large cans that will need to be wheeled in. ;)

[kb2vxa]

I can see you don't know squat about transformers so take my learned advice and fill it with oil. If you try running it dry I sure as hell don't want to be anywhere around when you apply power. I'm through.

[NQ6U]

I can see you don't know squat about transformers so take my learned advice and fill it with oil. If you try running it dry I sure as hell don't want to be anywhere around when you apply power. I'm through.

Hello.

You've forgotten that Hajji Rudi inhabits Rudy World.
Rudy World is flat, and laws of physics or thermodynamics don't apply there.
You can build a perpetual motion machine out of a Bell 47 APU and some old Motorola radio parts.
Hajji Rudi can build one, and have enough parts left over for two laser death rays and a shuttle to get him back to the mother ship.

[KA5PIU]

Hello.

Already applied power, while at the yard, while dry.
True, the oil acts as both an insulator and thermal conductor however in this application it will be run in reverse, the secondary will be the primary.
Since this is a 2200 volt unit that was constructed with the same level of insulation as a 7200 volt unit voltage breakdown is not an issue.
In fact the manufacturer supplies the exact same core in both a dry and wet configuration, and that was what I was looking for.
I have people on the engineering team helping me build this thing, this is a joint effort like most of what I do.
I am the equipment operator and truck driver of the team, I help erect the big stuff.
I do things like find old traffic control boxes that we put our repeater in and take that to the site.
I erect towers, and I mean towers, 90 foot tall thing is our small one.

[KA5PIU]

Hello.

Ran it into a load bank of twenty 300 watt light bulbs for 5 minutes after the vapor degreasing, pretty much the maximum amount of current I can come up with on 220 anyway.
It gets warm but not by any means hot.
Remember that this thing is designed to provide over 20 kVA, turns out to be way overkill.
I also have a dry transformer and a 5kVA pole pig.
The 5kVA unit will be cleaned next weekend and also vapor degreased and both cans will get sand blasted and primed.
What held me off on the 5 kVA unit is a broken insulator but I now have a replacement.
Again, this is going to be run well within its ratings.

[W7XF]

WART

[w3bny]

How do you do that? Do the PCB's fall out of the oil on the ground or something?

They use Melitta coffee filters...a metric ass load of them!

[W5GA]

They use Melitta coffee filters...a metric ass load of them!
Must be the brown ones, not the bleached white ones.

[w3bny]

I can see you don't know squat about transformers so take my learned advice and fill it with oil. If you try running it dry I sure as hell don't want to be anywhere around when you apply power. I'm through.

De-ionized water...thats the way to go!

[KA5PIU]

De-ionized water...thats the way to go!

Hello.

If the water were absolutely pure it would work, water is not a conductor.
And, both ABB and GE produce this transformer in 3 form factors.
The square pole pig that is more common in Europe can be oil filled or dry.
But the core has a rating chart for each application, for this core.
Even if I were to have to de-rate it 80% I will be more than 100% within ratings.

[NQ6U]

They use Melitta coffee filters...a metric ass load of them!

Hey, Charles—what was the ratio of metric assloads to metric shit-tons again?

[KG4CGC]

1.2:1

[w3bny]

Did you account for density variations?

[W5GA]

you forgot to divide by Charmin.

[N8YX]

you forgot to divide by Charmin.
...the Whipple Effect...

[KA5PIU]

Hello.

The standard voltages for the high line are 2200 volt on up and the insulation standards are the same for all of them.
Since this is a 2200 volt unit it will be well below the operating voltage limits.
And, to add to the safety factor, this unit has 2 primary windings and can be run on 1100 volts.
The dry transformer is 540, 570, 600VAC primary with 120/240 secondary, 60 amp maximum.
Safety is the first concern and all testing has been done with extreme caution in mind.
Once completed this will be as safe as can be made.
One of the reasons to run the transformer dry is to look for any signs of discharge with a corona stick while subjecting it to high voltage, none were found.

[kb2vxa]

I was working in the shack late one night
When my eyes beheld an eerie sight
From his pole pig his hand began to rise
And suddenly to my surprise...

YYYAAAaaa!!!

[KA5PIU]

Hello.

Electric fence insulators are rated at only a KV or 2.
Even the "Tiny" power line insulators are rated at 10+ KV!.
The stuff rated for service entry is good for 600 volts but is heavy enough for the large wires that electric service uses.
So, I am now looking at better insulators, used power line insulators to be exact.
The local utility does not reuse old hardware, it gets scrapped, a bonanza for me.