# Transformer question



## MDShunk (Jan 7, 2007)

They call it an autotransformer because it's relatively small and you can carry it in your car. Larger ones are truck transformers, but we just call those transformers.


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## eutecticalloy (Dec 12, 2010)

Autotransformers can be particularily dangerous. They are typically one coil with multiple taps for different voltages. 

I would assume H0 is ground however you shouldn't play with something if you don't understand the schematics. 

Post pics.


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## kaboler (Dec 1, 2010)

eutecticalloy said:


> I would assume H0 is ground however you shouldn't play with something if you don't understand the schematics.
> 
> Post pics.


I can't seem to get my phone to email me the pictures. Maybe my phone isn't set up for it. Company phone, and only a few things work like they should.

Anyway, the boss is going to check it out tomorrow. It's not live either. The power company has to come.

Good work for me. I'm exhausted. I bent so much 3/0 today. Going to sleep now. I dug up my "pocket handbook" (canadian electrical code) and it seems like H0 is ground, but that's why I'm making sure my boss is going out there. It's one thing to embarass myself, but it's totally another thing to embarass the company I work for hahahaha.


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## eutecticalloy (Dec 12, 2010)

kaboler said:


> I can't seem to get my phone to email me the pictures. Maybe my phone isn't set up for it. Company phone, and only a few things work like they should.
> 
> Anyway, the boss is going to check it out tomorrow. It's not live either. The power company has to come.
> 
> Good work for me. I'm exhausted. I bent so much 3/0 today. Going to sleep now. I dug up my "pocket handbook" (canadian electrical code) and it seems like H0 is ground, but that's why I'm making sure my boss is going out there. It's one thing to embarass myself, but it's totally another thing to embarass the company I work for hahahaha.


Does the diagram show three "x"s or more?


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## MDShunk (Jan 7, 2007)

Kaboler, as much as most of your posts irritate me, I have to hand it to you. You're not afraid to dive in, headlong, into stuff you only barely understand. Most guys would discourage that, but I'm here to tell you, I've built a successful career out of messing around with stuff I don't fully understand. All I can say is, keep up the good work, stay passionate, and keep learning. Sounds like you're with a half-decent shop that gives you a good mix of interesting stuff to do. As long as you have someone to fall back on when you get stuck, like your boss, that's a great situation. That's like gold. Learn all you can. When it gets boring, move on to another shop and learn some more stuff. The more well-rounded you are, the more valuable you are to the trade, and the more employable you become. Please, know your limits, but keep on learning!


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## Jmohl (Apr 26, 2011)

Kaboler, I would like to echo what Marc said. Having curiosity and enthusiasm are great traits. A big ego especially in someone so new to the trade will turn everyone against you. Question, question, question, listen, listen listen. When you have something to contribute that is based on what you know and not what you think, then people might listen.


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## brian john (Mar 11, 2007)

Post the manufacture, model, input and output voltages required.


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## jwjrw (Jan 14, 2010)

MDShunk said:


> Kaboler, as much as most of your posts irritate me, I have to hand it to you. You're not afraid to dive in, headlong, into stuff you only barely understand. Most guys would discourage that, but I'm here to tell you, I've built a successful career out of messing around with stuff I don't fully understand. All I can say is, keep up the good work, stay passionate, and keep learning. Sounds like you're with a half-decent shop that gives you a good mix of interesting stuff to do. As long as you have someone to fall back on when you get stuck, like your boss, that's a great situation. That's like gold. Learn all you can. When it gets boring, move on to another shop and learn some more stuff. The more well-rounded you are, the more valuable you are to the trade, and the more employable you become. Please, know your limits, but keep on learning!




If I only did what I knew how to do I wouldn't bid many of the things I do. I have learned most of the little I know that way.


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## brian john (Mar 11, 2007)

jwjrw said:


> If I only did what I knew how to do I wouldn't bid many of the things I do. I have learned most of the little I know that way.


 
I figured out a long time ago that electricians cannot read or use a phone. People ask how I became an expert in my field (AND I AM NO EXPERT), I read the instructions and call the manufactures.

Most manufactures are more than willing to help.


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## jwjrw (Jan 14, 2010)

brian john said:


> I figured out a long time ago that electricians cannot read or use a phone. People ask how I became an expert in my field (AND I AM NO EXPERT), I read the instructions and call the manufactures.
> 
> Most manufactures are more than willing to help.


I call tech support any time I need to. It has saved my a** more than once.


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## BBQ (Nov 16, 2010)

jwjrw said:


> If I only did what I knew how to do I wouldn't bid many of the things I do. I have learned most of the little I know that way.



So what do you know how to do? :laughing:


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## jwjrw (Jan 14, 2010)

BBQ said:


> So what do you know how to do? :laughing:




I know how to bid and run jobs that turn a nice profit....and how to piss women off without even trying. :001_huh: :laughing:


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## BBQ (Nov 16, 2010)

brian john said:


> I figured out a long time ago that electricians cannot read or use a phone. People ask how I became an expert in my field (AND I AM NO EXPERT), I read the instructions and call the manufactures.
> 
> Most manufactures are more than willing to help.



I am a firm believer in reading the manuals, but I almost refuse to call anyone. I wish I could change that about myself but I can't seem to.

The service guys that are under me figure out many tough problems because they will pick up the phone and talk to tech support.


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## user4818 (Jan 15, 2009)

BBQ said:


> I am a firm believer in reading the manuals, but I almost refuse to call anyone. I wish I could change that about myself but I can't seem to.


That's because you're pig headed and your ego gets in the way.

There, I said it. :thumbup:


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## BBQ (Nov 16, 2010)

Peter D said:


> That's because you're pig headed and your ego gets in the way.


No doubt there is some level of truth to that.

But I can ask questions here, and I ask people questions in person but I hate dealing with people on the phone. I think that mostly stems from the fact I assume they are just operators reading from a screen and not people that have hands on experience with what I am working on.


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## user4818 (Jan 15, 2009)

BBQ said:


> No doubt there is some level of truth to that.
> 
> But I can ask questions here, and I ask people questions in person but I hate dealing with people on the phone. I think that mostly stems from the fact I assume they are just operators reading from a screen and not people that have hands on experience with what I am working on.


True. 

Quite frankly, I don't have these kind of issues you guys talk about because I'm an electrical genius. :laughing:


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## brian john (Mar 11, 2007)

jwjrw said:


> I know how to bid and run jobs that turn a nice profit....and how to piss women off without even trying. :001_huh: :laughing:


 
Man we are twin brothers, I figure I must be a real A-hole, because I know several women I highly respect and appreciate their opinions and I seem to have spent my life pissing them off.


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## jwjrw (Jan 14, 2010)

brian john said:


> Man we are twin brothers, I figure I must be a real A-hole, because I know several women I highly respect and appreciate their opinions and I seem to have spent my life pissing them off.



Except I am the younger dumber brother. :blink::laughing:

I hope that one day I know half of what you know......if I'm lucky....:thumbsup:


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## Electric_Light (Apr 6, 2010)

I don't know why they're called that, but auto transformers are typically used when neutral or ground reference doesn't need to be changed and the size is proportional to voltage change needed. 

A 20kVA 208v L-L to 240v L-L can be auto xfrmr'd and the transformer would only have to actually handle about 3.1kVA. 

(240-208)/208 * 20 =
3.077kVA

If you want to go from 277v L-N to 240/120-N-120, you're changing grounding reference, so you will have to use a normal transformer.


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## RIVETER (Sep 26, 2009)

kaboler said:


> I was sent out today to run power from a tap box, through a wall, to a disconnect, and down to a transformer.
> 
> But, it was a bit confusing to me. It was called an "autotransformer". I don't know why they call it that, but it supplies 600v stepped down to 480 and 240. Supplies 2 voltages.
> 
> ...


An auto transformer is a transformer that has a portion of it's primary used as it's secondary.


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## Jlarson (Jun 28, 2009)

BBQ said:


> I am a firm believer in reading the manuals, but I almost refuse to call anyone. I wish I could change that about myself but I can't seem to.


I don't read manuals besides the wiring diagrams and maybe the code sections or call tech support. I just dig in with my laptop, meter and o-scope. :laughing:


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## kaboler (Dec 1, 2010)

RIVETER said:


> An auto transformer is a transformer that has a portion of it's primary used as it's secondary.


No wonder it was so tiny. It was 150kva and I could push it around alone! I can barely move a 75kva by myself if it were a regular transformer.

Just read wikipedia about autotransformer, and indeed that's the way it is. No wonder the taps went into the middle of the coils. Slick stuff!!!!!!


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## HARRY304E (Sep 15, 2010)

Jlarson said:


> I don't read manuals . :laughing:


That would really screw you up....:blink::laughing::laughing:


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## Phil DeBlanc (May 29, 2010)

Ya think maybe, just maybe its called an autotransformer because it's the same winding system used in an old fashioned automobile spark coil?


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## Phil DeBlanc (May 29, 2010)

MDShunk said:


> They call it an autotransformer because it's relatively small and you can carry it in your car. Larger ones are truck transformers, but we just call those transformers.


What do we call the big transformers that ride on trailers with 30 wheels under them and the more bigger transformers that ride on chochoo trains?


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## oldtimer (Jun 10, 2010)

Phil DeBlanc said:


> What do we call the big transformers that ride on trailers with 30 wheels under them and the more bigger transformers that ride on chochoo trains?


 I don't know..... I didn't see the movie! :laughing::laughing:

The name Optimus Prime comes to mind!!


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## Big John (May 23, 2010)

Phil DeBlanc said:


> Ya think maybe, just maybe its called an autotransformer because it's the same winding system used in an old fashioned automobile spark coil?


 I always heard "auto" and thought of "automatic" but that doesn't make sense.

I looked it up and the description was "auto" as in "self" (think "autobiography").

With an autotransformer the coil transforms voltage within itself instead of using a separate secondary, hence the name.








-John


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## Electric_Light (Apr 6, 2010)

kaboler said:


> No wonder it was so tiny. It was 150kva and I could push it around alone! I can barely move a 75kva by myself if it were a regular transformer.
> 
> Just read wikipedia about autotransformer, and indeed that's the way it is. No wonder the taps went into the middle of the coils. Slick stuff!!!!!!


The actual kVA of the transformer itself depends on the voltage differential.

Given the same kVA rating a 600v to 120v auto transformer would weigh about the same as a normal 120:480v transformer.


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## MDShunk (Jan 7, 2007)

Phil DeBlanc said:


> What do we call the big transformers that ride on trailers with 30 wheels under them and the more bigger transformers that ride on chochoo trains?


Yeah, I didn't want to confuse him.


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## kaboler (Dec 1, 2010)

Wikipedia:


> The auto prefix refers to the single coil acting on itself rather than any automatic mechanism.


"auto- regarding oneself"

Anyway, good talking about calling the manufacturer. Something I'll remember.


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## MDShunk (Jan 7, 2007)

kaboler said:


> Wikipedia:
> 
> 
> "auto- regarding oneself"
> ...


I know some employers and some jobsites require that you leave your cell phone in your car/truck, but I've got to tell you that calling tech support is a very efficient way to get your questions answered. The manufacturers ALL want you to both understand their product and use it properly. Don't hesitate to dial the phone for a quick 5 or 10 minute call. That can sometimes save you hours of spinning your wheels.


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## Electric_Light (Apr 6, 2010)

auto means self.
Perhaps, autotransformer came from the fact that it uses one winding itself as part of the secondary


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