480Y/240V 3 PH to 240v 1PH

[mattman9]

Hey everyone. I just moved my furniture and fabrication business into a new warehouse space. We have a full wood shop, welding area, and CNC Router.

I was super pumped to find out that the space had ample electricity already, but I’ve come to find out that it’s too much for my modest shop.

My portion of the the warehouse space has a dedicated 480Y/277V 3PH 4 wire panel.

There are 4 separate 480 3PH circuits already on the panel that were used for welders. The previous tenant were using much larger equipment than I am. The outlets are still installed.

Most of my stuff is 240v single phase. I’m not a full production shop. I mainly do one off custom projects.
The 240v equipment is more than enough for what I do(and can afford).

I may have one piece of equipment that is 240v 3 phase.

Is a transformer the most cost effective solution here?
I don’t know a lot about this level of electricity so I’m not quite sure what I’m looking for and three phase makes my head hurt.

I know I can just throw money at it, but this isn’t something I budgeted for.

There is another 240v single phase panel next to it, but we were hoping to keep them separate so I could have one panel for my shop (the 480) and the other panel for the other business would run off the 240 panel. Each has there own meter so it would make keeping track of usage very easy.

This isn’t a must, but it would be nice just so we can split the electricity usage fairly.

Thanks for any help.

 

[Norcal]

If you have 480V power & wish to run 208V or 240V equipment off it a transformer is your only choice, word of warning, it ain't gonna be cheap.

 

[Innovate1]

A power meter to know how to split the 240V bill might be cheaper than transformers.

 

[theoldwizard1]

Most of my stuff is 240v single phase. I’m not a full production shop. I mainly do one off custom projects.
The 240v equipment is more than enough for what I do(and can afford).

Anything with a motor can be replaced with a 3 phase motor. 3 phase motors are much more efficient. In the long run, this is your best option.

"Controls" for anything automated likely use 120VAC. You need to run a separate 120 line to that load. Might be a bit tricky especially wiring a emergency stop button to kill both !

 

[nadogail]

A Used transformer might be your most economical solution.

 

[u3b3rg33k]

Anything with a motor can be replaced with a 3 phase motor. 3 phase motors are much more efficient. In the long run, this is your best option.

"Controls" for anything automated likely use 120VAC. You need to run a separate 120 line to that load. Might be a bit tricky especially wiring a emergency stop button to kill both !

ALMOST all our old machines are 240v 3ø with a local 1ø 240-120v dry transformer for (sigh) 120v controls. that way if you hit the main disconnect for a machine, the whole thing is cold.

not a fan of 120v controls personally, but I get it, and it works.

 

[wyliesdiesels]

A power meter to know how to split the 240V bill might be cheaper than transformers.

deleted

 

[wyliesdiesels]

Hey everyone. I just moved my furniture and fabrication business into a new warehouse space. We have a full wood shop, welding area, and CNC Router.

I was super pumped to find out that the space had ample electricity already, but I’ve come to find out that it’s too much for my modest shop.

My portion of the the warehouse space has a dedicated 480Y/277V 3PH 4 wire panel.

There are 4 separate 480 3PH circuits already on the panel that were used for welders. The previous tenant were using much larger equipment than I am. The outlets are still installed.

Most of my stuff is 240v single phase. I’m not a full production shop. I mainly do one off custom projects.
The 240v equipment is more than enough for what I do(and can afford).

I may have one piece of equipment that is 240v 3 phase.

Is a transformer the most cost effective solution here?
I don’t know a lot about this level of electricity so I’m not quite sure what I’m looking for and three phase makes my head hurt.

I know I can just throw money at it, but this isn’t something I budgeted for.

There is another 240v single phase panel next to it, but we were hoping to keep them separate so I could have one panel for my shop (the 480) and the other panel for the other business would run off the 240 panel. Each has there own meter so it would make keeping track of usage very easy.

This isn’t a must, but it would be nice just so we can split the electricity usage fairly.

Thanks for any help.

The only way to get 120/240v split phase or 3 phase from 480v is with a dry type step down transformer

 

[wyliesdiesels]

ALMOST all our old machines are 240v 3ø with a local 1ø 240-120v dry transformer for (sigh) 120v controls. that way if you hit the main disconnect for a machine, the whole thing is cold.

not a fan of 120v controls personally, but I get it, and it works.

Couldve just changed the controls to run on 240v

 

[Innovate1]

Huh? If the building is fed 480v the only way to have 240v is with a step down transformer. You dont get 240v from 480v without a transformer.

He said he had another panel on another meter with 240 single phase. The only issue was accounting for who owed what for power if they run drops from that panel for different users. Don't know how feasible it is but was suggesting a subpanel off the main 240 panel with a privately owned meter between panels to know how much is used. The accounting gets a little messy but thinking that would be cheaper than a big transformer.

If they do a transformer maybe a buck from 277. It only has to handle (277-240)/240 of the power that way or about 15% of the power. Makes the transformer MUCH smaller. That's assuming one line can be neutral rather than split phase.

 

[wyliesdiesels]

He said he had another panel on another meter with 240 single phase. The only issue was accounting for who owed what for power if they run drops from that panel for different users. Don't know how feasible it is but was suggesting a subpanel off the main 240 panel with a privately owned meter between panels to know how much is used. The accounting gets a little messy but thinking that would be cheaper than a big transformer.

If they do a transformer maybe a buck from 277. It only has to handle (277-240)/240 of the power that way or about 15% of the power. Makes the transformer MUCH smaller. That's assuming one line can be neutral rather than split phase.

Aww i missed that. Serves me right for reading too fast

 

[alfredeneuman]

The only way to get 120/240v split phase or 3 phase from 480v is with a dry type step down transformer

Oil filled transformers are available as well, but cost way more than dry types.

 

[cycle61]

Oil filled transformers are available as well, but cost way more than dry types.

We could also suggest a motor/generator set but now things are getting silly.

Honestly, a modest 480/240 transformer isn't all that expensive. Depending on total size needed, you should be able to get one for a couple grand. Feed it from the 480/3 panel via an appropriate size breaker, from the transformer secondary to a 240/120 panel, and you can pull your loads from there.

3-Phase 480V Delta - 240V Delta / 120

Step-down transformer to convert 3-phase 480V to 3-phase 240V. This unit can be used for reverse feeding. Great for CNC machines, fabrication tools, and more.

www.maddoxtransformer.com

 

[rancherbill]

How big is the office circuitry / panel? It's 240/120. You say you're a SMALL shop which says to me that you are not running everything all the time. Maybe with a little crafty code compliant legal rewiring it's all there already.

 

[wyliesdiesels]

Oil filled transformers are available as well, but cost way more than dry types.

when was the last time you saw an oil filled transformer in a building? i bet theyre only available via custom order

 

[Norcal]

when was the last time you saw an oil filled transformer in a building? i bet theyre only available via custom order

Out of my league but would assume a vault would have to be constructed for it.

 

[alfredeneuman]

when was the last time you saw an oil filled transformer in a building? i bet theyre only available via custom order

Out of my league but would assume a vault would have to be constructed for it.

It could be an outdoor pad mount too.

 

[nadogail]

I bought Transformers from an electrical salvage dealer.

 

[Steve from Socal]

I have three 100KVA oil filled transformers (no PCB's) for my 480-240/120, they are on a rack outside. I have a 15 KVA dry transformer that I would sell for 1500.00 I think it is a delta Wye? Have to dig it out, came with my CNC router

 

[wyliesdiesels]

I have three 100KVA oil filled transformers (no PCB's) for my 480-240/120, they are on a rack outside. I have a 15 KVA dry transformer that I would sell for 1500.00 I think it is a delta Wye? Have to dig it out, came with my CNC router

Got pics?

 

[Steve from Socal]

I will take some in the AM

 

[u3b3rg33k]

Couldve just changed the controls to run on 240v

it's got 120V temp controllers from the 60s in it, pilot lights, relays etc. a project not worth starting. I'd go 24VDC if I was gonna bother. much safer to futz with.

 

[Steve from Socal]

Well I got the extra transformer and the axis drive confused? The transformer I have that is excess to my needs is a 45KVA 480 Delta-208/120 Wye transformer.

I thought this was 240 but now recall all the servo drives in that machine are 200 volt.

 

[wyliesdiesels]

Well I got the extra transformer and the axis drive confused? The transformer I have that is excess to my needs is a 45KVA 480 Delta-208/120 Wye transformer.

I thought this was 240 but now recall all the servo drives in that machine are 200 volt.

thats not oil filled either. its a dry type

Square D 45T3HNV :: Transformer, Dry Type, 45KVA, 3PH, 480 Delta - 208Y/120 Shielded :: Rexel USA

Transformer, Dry Type, 45 KVA, 3-Phase, 480 Delta - 208Y/120 Volt AC, Shielded, Non-Ventilated, Cat #: 45T3HNV, Mfr: Square D

www.rexelusa.com

 

[Steve from Socal]

I never said the excess transformer was wet, my service is 480 Delta and I DO have three oil filled transformers for my 240/120 loads, I have no 208 distributed power. Here are the three 100KVA oil filled.

 

[wyliesdiesels]

oh i miss understood

what type of transformer is the PoCo using to deliver your 480D? is it corner grounded or floating?

 

[Steve from Socal]

The power is floating, I am on my own transformers on the pole. My building is 480 Delta everyone on the other side of the alley is 240. My property is one block from street to street and, from alley to street. I am zoned M3 and the other side of the alley is M1-C2

 

[wyliesdiesels]

The power is floating, I am on my own transformers on the pole. My building is 480 Delta everyone on the other side of the alley is 240. My property is one block from street to street and, from alley to street. I am zoned M3 and the other side of the alley is M1-C2

Do you have ground fault monitoring?

 

[Steve from Socal]

No I don't, I have several VFD's on machines that would not play well with a corner grounded system.

 

[Norcal]

No I don't, I have several VFD's on machines that would not play well with a corner grounded system.

With that system ground detectors would be used.

 

[wyliesdiesels]

No I don't, I have several VFD's on machines that would not play well with a corner grounded system.

umm ground fault monitoring and corner grounding are 2 very different things and they do not go together.

if you have a corner grounded system you would not need ground fault monitoring. also VFDs should have no issue with a ground fault monitoring system.

ground fault monitoring is for floating/ungrounded systems and is required by code. you most definitely should add it as its potentially dangerous without it. imagine one phase ends up bonding to a metal surface such as a panel or conduit. then a second phase does the same thing. the resultant arc flash and fireworks from a short circuit between the phases will be very dangerous.

ground fault monitoring can be as simple as 3 industrial rated 600v bulbs wired in wye (1 phase to 1 pole on each base and other poles on the bases wired to each other & ground) or electronic monitoring.

 

[Steve from Socal]

I know that corner grounding and floating ground/ground fault monitoring are very different. Just put that out there to note that I do have several VFD's that are not happy on a corner grounded system.

A ground fault monitor IS a good idea, the light bulb concept sounds simple enough. That woud be a good visual at or near my main, I have 6 sub panels all over a 27K sq ft area. Having a visual warning at each panel would still be widely out of sight of most of the shop?

 

[wyliesdiesels]

I know that corner grounding and floating ground/ground fault monitoring are very different. Just put that out there to note that I do have several VFD's that are not happy on a corner grounded system.

A ground fault monitor IS a good idea, the light bulb concept sounds simple enough. That woud be a good visual at or near my main, I have 6 sub panels all over a 27K sq ft area. Having a visual warning at each panel would still be widely out of sight of most of the shop?

the ground fault monitoring needs to be at the main service panel.

but you could wire up some relays to run off the main GF monitor and wire them to visible indicators or even a buzzer at remote locations...

 

[wyliesdiesels]

one note- forgot to include in post #31 that the wye side of the bulb bases need to also be connected to "ground".

 

[u3b3rg33k]

I know that corner grounding and floating ground/ground fault monitoring are very different. Just put that out there to note that I do have several VFD's that are not happy on a corner grounded system.

what don't they like about it? we're 240 corner grounded and I've never had a VFD complain.

 

[wyliesdiesels]

what don't they like about it? we're 240 corner grounded and I've never had a VFD complain.

Ive read about VFD issues due to the grounded phase but i have no personal experience

 

[Steve from Socal]

I have 60, 30, 15 HP and several smaller drives that would have issues. These are all 480 volt, they are mostly European with a couple Japanese and US manufactures.

 

[u3b3rg33k]

Do the problem drives have EMC filters? most of the manuals say to pull the screw on a corner ground system. https://solutioncenter.yaskawa.com/selfservice/viewContent.do?externalId=13262&sliceId=1