CA-ON Looking for 240-600v 6-9kva 3ph transformer

[Dan Dubeau]

As the title states, I'm looking for a 3 phase step up transformer 240-600v (or one that can be backfed), in the 6kva-9kva range. Phase quest has a 6kva new/refurb @ $914. Lots of used ones that are bigger, different voltage etc that are in the $3-500 range. Which is the price range where I'm hoping to find one. I'm just tired of scouring marketplace and kijiji every day looking for a deal, and would like to start puting this together over the xmas holidays. I've called a few kijiji ads stating they have a bunch more in stock, but nobody has a little guy like this.

Looking for leads if anyone has a good transformer guy, or has one kicking around the shop. In eastern gta/kawarthas preferably, but am willing to head out for a road trip.

Thanks in advance, Dan.

 

[Tom Kitta]

Look at auctions. I have 240v --> 600v back fed and then I have 600v --> 480v. It can take more than a year to find one. I think my 240v to 600v is at least 10kwh.

Also you may look into rewiring one a little bit - i.e. make your own pull outs. This is how my 240v to 600v is setup. I.e. make sure what you get is not sunk in a block of epoxy. Thus you can get 240v to 480v and make it 600v or more likely 550v. Many transformers have +- 15% or at least 5% out of the box.

 

[TorontoBuilder]

As the title states, I'm looking for a 3 phase step up transformer 240-600v (or one that can be backfed), in the 6kva-9kva range. Phase quest has a 6kva new/refurb @ $914. Lots of used ones that are bigger, different voltage etc that are in the $3-500 range. Which is the price range where I'm hoping to find one. I'm just tired of scouring marketplace and kijiji every day looking for a deal, and would like to start puting this together over the xmas holidays. I've called a few kijiji ads stating they have a bunch more in stock, but nobody has a little guy like this.

Looking for leads if anyone has a good transformer guy, or has one kicking around the shop. In eastern gta/kawarthas preferably, but am willing to head out for a road trip.

Thanks in advance, Dan.

There was a 15 KVA 600 - 240 volt 3 phase auto transformer for sale a month ago at Canadian Printing equipment limited for $350 IIRC, and shipping of $400 to GTA.

You should email and ask if it has been sold. The only reason I didn't buy it was because I found a RPC and transformer packaged together at a killer price.

 

[Dan Dubeau]

Thanks Tom, I'm afraid my electrical expertise falls a bit short of being competent and confident enough to pull out my own taps. But I'm not afraid of learning new stuff.

A question though, as you seem knowledgeable. Is any transformer capable of being back fed? I've read mixed things on that, and up until I started researching recently I always thought they could go either way. But now I'm not sure, which is why I put that in there. If so, that widens my search a bit. If not, what makes one capable and another not?

Bigger ones are easier to find. 15-30kva, but they're just too damn big, and I don't have that much room to put it in my little shop. Seems there is a big size difference once you get under 10. Nor do I need one that big right now.

The phase quest price I "could" stomach if I had to, it's much cheaper than the quote I got from our resident commercial electrician we use for stuff at work, but i'm too damn cheap, and am used to seeing them go for cheap. I'll continue to search daily, for one, amongst other things.

 

[TorontoBuilder]

Thanks Tom, I'm afraid my electrical expertise falls a bit short of being competent and confident enough to pull out my own taps. But I'm not afraid of learning new stuff.

A question though, as you seem knowledgeable. Is any transformer capable of being back fed? I've read mixed things on that, and up until I started researching recently I always thought they could go either way. But now I'm not sure, which is why I put that in there. If so, that widens my search a bit. If not, what makes one capable and another not?

Bigger ones are easier to find. 15-30kva, but they're just too damn big, and I don't have that much room to put it in my little shop. Seems there is a big size difference once you get under 10. Nor do I need one that big right now.

The phase quest price I "could" stomach if I had to, it's much cheaper than the quote I got from our resident commercial electrician we use for stuff at work, but i'm too damn cheap, and am used to seeing them go for cheap. I'll continue to search daily, for one, amongst other things.

not every transformer can be fed from the secondary to the primary side.

The least expensive option is the autotransformer. I'll get you a marcus model number if you'd like to aid your search efforts. This size is very hard to find. I had to look long and hard for months.

 

[Tom Kitta]

Thanks Tom, I'm afraid my electrical expertise falls a bit short of being competent and confident enough to pull out my own taps. But I'm not afraid of learning new stuff.

A question though, as you seem knowledgeable. Is any transformer capable of being back fed? I've read mixed things on that, and up until I started researching recently I always thought they could go either way. But now I'm not sure, which is why I put that in there. If so, that widens my search a bit. If not, what makes one capable and another not?

Bigger ones are easier to find. 15-30kva, but they're just too damn big, and I don't have that much room to put it in my little shop. Seems there is a big size difference once you get under 10. Nor do I need one that big right now.

The phase quest price I "could" stomach if I had to, it's much cheaper than the quote I got from our resident commercial electrician we use for stuff at work, but i'm too damn cheap, and am used to seeing them go for cheap. I'll continue to search daily, for one, amongst other things.

Well, almost any transformer can be back fed - the problem is how you get voltages - if its input 3 legs and output 3 legs - then yes - you can feed it back - but if its 3 legs in and say 1 leg + neutral out then no.

Also be aware of epoxy filled transformers - you have zero options with these - what they provide is what you get.

I am sure there are some exotic rare transformers out there that are not standard delta - Y.

If you need little 600v power - like not a lot of 600v, you can produce 600v by using any motor powering a 600v motor - i.e. you can have 1 or 3 phase 240v motor power a 600v motor through flexible coupling and then from that 600v motor you have 600v out. Getting 600v motors is super easy and very cheap as no one really wants these. This may be smaller solution that say 15k transformer - depending on how much HP you actually need.

Size wise yes, the 10+ are big, my 600 to 480 which I think is a 6kw is like a big toaster oven - very small.

Also for back feeding there may be warranty issues and you may have to de-rate the unit - not super important stuff.

 

[Dan Dubeau]

Thanks Tom. I'm only building a 5hp rpc, to power a mill, and shaper, and possibly a hardinge (still working on that deal), and eventually a surface grinder. So all small loads. I could probably even get away with a 3kva. The hardinge, and grinder will preferably be VFD powered so not even run through the converter. I just want a 6-9 for some wiggle room, without getting too big.

There's a pretty cheap 20kva transformer in town here, I might just grab for the time being to get up and running, until I can find a smaller more appropriately sized one, and maybe flip it. I was hoping this would make a nice Christmas break project, but seem to be striking out the last couple weeks.

As one who browses markeptplace, and kijiji on a pretty regular basis, you get to see the eb and flow of prices, and availability of things. If I had unlimited money, and space, I'd buy every great deal I came across. But I'm pretty limited in both these days, so when I always see things I "need" eventually, but not now, I let them go thinking I'll find one again when I need it. Very rarely do I actually "need" something right now, which is usually when you pay for it. I know I've seen a few small ones like this go for cheap over the years, which is why it's tough for my cheap ass to pay above the "bar" price set in my head lol.

Good, fast, cheap, you can only pick two. Good, and cheap are my favourites.

 

[Canadium]

I'm following this thread with intense interest! I'm hoping @Dan Dubeau that you succeed and tell us all about it because this is pretty much exactly what I want to do. I have a 5kVa step down transformer 600 to 220V that I was hoping to use reversed. I guess first thing I have to find out is if it has 3 output leads and 3 inputs?

 

[Proxule]

Well, almost any transformer can be back fed - the problem is how you get voltages - if its input 3 legs and output 3 legs - then yes - you can feed it back - but if its 3 legs in and say 1 leg + neutral out then no.

Also be aware of epoxy filled transformers - you have zero options with these - what they provide is what you get.

I am sure there are some exotic rare transformers out there that are not standard delta - Y.

If you need little 600v power - like not a lot of 600v, you can produce 600v by using any motor powering a 600v motor - i.e. you can have 1 or 3 phase 240v motor power a 600v motor through flexible coupling and then from that 600v motor you have 600v out. Getting 600v motors is super easy and very cheap as no one really wants these. This may be smaller solution that say 15k transformer - depending on how much HP you actually need.

Size wise yes, the 10+ are big, my 600 to 480 which I think is a 6kw is like a big toaster oven - very small.

Also for back feeding there may be warranty issues and you may have to de-rate the unit - not super important stuff.

I was going to say all 3 phase xformers can be back-fed, Cutting the rated current in half if a step up is back-fed as a step down.
I would venture to say pulling 3 legs to make 460v from the 600 core shouldnt be too hard. Good idea!

 

[buckbrush]

When back feeding a transformer, ground fault lights are required on the ungrounded (600v) side.

 

[Tom Kitta]

I was going to say all 3 phase xformers can be back-fed, Cutting the rated current in half if a step up is back-fed as a step down.
I would venture to say pulling 3 legs to make 460v from the 600 core shouldnt be too hard. Good idea!

Usually you get more 600v transformers than 480v. Yes, you can pull legs out but it may be difficult to drop all the way from 600v to 480v - the extra legs are almost certainly going to be well under layers of other wires.

I did that BTW - got extra legs out as transformer was 208 - 600v and when fed with 240v it was too high.

I also have it feeding a 480 - 600 transformer - this way I have 3x voltages 240, 480 and 600.

The 480-600 transformer is tiny. For 6kv its a toaster oven sized.

 

[Dan Dubeau]

So, an unexpected 5hr door to door kijiji roadtrip yesterday netted me this guy.

I think it'll work fine (would love to hear opinions from those more experienced though?), It has multiple taps on the high side, so I'm hoping I can get what I need out of it once it's hooked up.

Now it's time to dig through my horded electrical components to see what I have, and make an ordering inventory to finish building my panel. I'm 2/3 of the way there.... I'll start a build thread when I get there for critique and questions I'll no doubt have...

https://www.a1parts.ca/index.html looks to have pretty much everything I might need, but if there are other/better sources I'd love to hear about them. I'd love to find more Canadian sources of surplus electrical/mechanical stuff.

Browsing around that site made me miss walking around active surplus on queen when I lived downtown TO.