# Shop Electricity Question



## gafftaper (Aug 13, 2007)

Hi,
I just found out my shop is going to be wired for 208V 3 phase power. However the vast majority of Delta and Jet larger tools run 230V 1 phase power. 

I spoke to an electrician and he said that it's just a simple rewiring job to bring the outlet down to 1 phase. He figured that the saw would be just fine running on 208V instead of 230V.

I'm not an electricity expert. Does that sound right? Does it sound like something that it's better to avoid change orders with the building contractor and just hire an electrician to rewire an outlet later? Or should I fight to get them all changed to 230V 1 phase now, even if it costs a lot more? 

Opinions...


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## Grog12 (Aug 13, 2007)

Ooof....that's opinion #1
Opinion #2 is I'd want to spend the cash now to get it done right the first time. Electrically speaking (and I'm not the biggest phase expert) something sounds a little shakey in the info you've been given. Sure its simple to get 1 phase at the outlets...but me I'd want it to be the full on 230v with power tools. I don't like shortchanging non dimmable motors, arc lamps, and computers that much.

Stolen from wikipedia "Three phase systems may or may not have a neutral wire. A neutral wire allows the three phase system to use a higher voltage while still supporting lower voltage single phase appliances."

Random questions:

1) Why did you choose to be specced for 3-phase is the first place?
2) Do you forsee renting out your space?
3) What about film?


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## Van (Aug 13, 2007)

Errrrr. If the saw you get is capable of being run from 208 your fine. However, it's not "simple" to get 230v out of a 208 system. You can get 110v easy, just use a hot and the neutral. 208 and 230 require completely different phase taps off of the transformer. You can turn 220/230 into 208, effectively, by using a "rotophaser" but I don't know of anything other than setting up another transformer in the shop that will allow you to get 230/220 out of 208.


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## Grog12 (Aug 13, 2007)

Van said:


> Errrrr. If the saw you get is capable of being run from 208 your fine. However, it's not "simple" to get 230v out of a 208 system. You can get 110v easy, just use a hot and the neutral. 208 and 230 require completely different phase taps off of the transformer. You can turn 220/230 into 208, effectively, by using a "rotophaser" but I don't know of anything other than setting up another transformer in the shop that will allow you to get 230/220 out of 208.



This is why I like Van...he assures me I'm not completly crazy and words my incoherent ramblings into managible sentences.


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## Footer (Aug 13, 2007)

I would get them to put in at least one 30 amp or more 3 phase tap in for automation. You might now need it now, but somewhere down the line it will come in handy. Testing things before the go into the space is always a good thing.


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## gafftaper (Aug 13, 2007)

Footer4321 said:


> I would get them to put in at least one 30 amp or more 3 phase tap in for automation. You might now need it now, but somewhere down the line it will come in handy. Testing things before the go into the space is always a good thing.



Ohh good idea.


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## SHARYNF (Aug 14, 2007)

It usually means that there will be a three phase 208 panel in your shop and that you will have the option of 110 volt outlets, 208 outlets and three phase 208. IF you equipment is set up to run 208 you will be fine. Most equipment is.

TYPICALLY you might find some three Phase 240 items with large motors but USUALLY this is not on your shop type equipment, might be on a milling machine, in a metal shop. 

In industrial settings instead of three phase wye you would have delta or corner delta, but this is not the usual in you type of setup

Sharyn


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## Van (Aug 14, 2007)

SHARYNF said:


> It usually means that there will be a three phase 208 panel in your shop and that you will have the option of 110 volt outlets, 208 outlets and three phase 208. IF you equipment is set up to run 208 you will be fine. Most equipment is.
> 
> TYPICALLY you might find some three Phase 240 items with large motors but USUALLY this is not on your shop type equipment, might be on a milling machine, in a metal shop.
> 
> ...


 

I gotta disagree, sorry. MOST shop tools are setup to operate on 220v or 110v. A 208 tablesaw is a very rare thing outside of an "Industrial" setting. The tools Gaff has outlined in most of his posts here are going to be 110 or 220v.


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## Footer (Aug 14, 2007)

Van said:


> I gotta disagree, sorry. MOST shop tools are setup to operate on 220v or 110v. A 208 tablesaw is a very rare thing outside of an "Industrial" setting. The tools Gaff has outlined in most of his posts here are going to be 110 or 220v.



As well as any welder you are running. Coming from someone that has spent the last 10 weeks with a 110v welder, get the 220 put in.


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## gafftaper (Aug 14, 2007)

I've found a Delta Tablesaw that runs at 200V 3 phase so I'm ok with my main shop centerpiece. I've got messages out to several manufacturers to see if their 220V/1ph bandsaws will run at 208V 1ph. I've had one electrician and the head of campus facilities tell me it shouldn't be a problem running 220V/1ph equipment on 208V/1ph... but I'm a little skeptical about that. I suppose when you are talking about a bandsaw your aren't exactly talking sophisticated electronics so the motor would just be slightly under powered and run a little slower. 

I'm told the whole campus is wired 208/3ph so it's a major deal to get me true 220... not sure how true that is.


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## ship (Aug 14, 2007)

I'm noting a bunch of 208v 1 phase listings above. 208v would be two phase not single phase. Three phase 120/208v taps in the shop would be nice but I would first ensure that your tools will run off 208v as opposed to the 120/240v single/two phase wye and not delta power. Different power types but sometimes they will be fine. Kind of like a high salt verses low salt diet. Don't experiment but do further check.


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## gafftaper (Aug 15, 2007)

ship said:


> I'm noting a bunch of 208v 1 phase listings above. 208v would be two phase not single phase. Three phase 120/208v taps in the shop would be nice but I would first ensure that your tools will run off 208v as opposed to the 120/240v single/two phase wye and not delta power. Different power types but sometimes they will be fine. Kind of like a high salt verses low salt diet. Don't experiment but do further check.



Well it's sounding like the shop WILL BE wired 110v all over the place and have three 208V 3 phase outlets. If I want I can of course split those 208's down to 1 phase 208. But that is apparently all i have to work with. I'm told it would be very expensive to get that changed. 

So, two questions:
1) Does it sound correct that it's a huge expensive deal to rewire my power from 208 V 3 phase up to 230? Is it a matter of just rewiring the panel? Is it a matter of running different lines from the street? The new theater is attached to a new 5 story building so the power is shared. I imagine all the HVAC for both building is being installed to run on 208 so any changes would have to be special for just my three outlets. 

2) Dumb question here. If my Dewalt sliding compound miter saw is a 120v saw, am I going to have a hard time running it on 110. 

I know I should really understand all this better.  I'm certainly getting a crash course this week.


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## SHARYNF (Aug 15, 2007)

It will be interesting to hear what your contacts with the Manufacturers say. Contrary to some of the comments above, in my experience the equipment that is listed as 220, will when you talk to the manufactures, run successfully at 208 as this configuration is very typical outside of a home environment. Most larger buildings, are all wired three phase, and do the the oddities of Delta, most are wye. IF on the other hand the device shows 240 volts then you do need to check a bit more, as the drop from 240 to 208 can be significant to performance, while the drop from 220 to 208 is usually in the safe range. IN many cases, and why it is important to check for listing/certification requirements the manufacturer needs to list the highest voltage the device is certified for, and is not required to list the lowest or the range. 

Being in AK and a marine environment run into this stuff all the time. It is possible to get a small transformer 15kw for instance a multi tap/isolation tranformer more likely from someone with marine experience. I have one on our boat, in allows on board support for 220 typical house power, BUT I have the option to connect it to a single 120 volt connection, a 208 connection off a dock wye, etc, I just select what taps I am connecting to. By selecting the windings, it can step up the 208 to full 220. Since your in Seattle area, I'd talk to some of the better marine wiring people and ask about this option if you are still concerned.

http://www.johnsoncoil.com/3phase.htm is the company that made the one we use. At least when you talk to Transformer people, they only talk about single and 3 phase, and rarely talk about 2 or split phase. 

Sharyn


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## icewolf08 (Aug 15, 2007)

gafftaper said:


> 1) Does it sound correct that it's a huge expensive deal to rewire my power from 208 V 3 phase up to 230? Is it a matter of just rewiring the panel? Is it a matter of running different lines from the street? The new theater is attached to a new 5 story building so the power is shared. I imagine all the HVAC for both building is being installed to run on 208 so any changes would have to be special for just my three outlets.


Yes, it is probably a pretty big deal to have the system rewired for 240 as you have to have a different transformer setup. The 120/208v system, as has been said is the most common for theatre applications and most other uses. This is the 3 phase Y (wye) setup. This provides 120v from any phase to neutral and 208v from phase to phase. To change it to a 120/240v system you would need a transformer wired for 3 phase delta where you center tap one winding for a neutral. In the Delta setup you would get 240v from phase to phase and 120v from two phases to neutral and one "wild leg" that gives 208v from phase to neutral.

As it turns out, if you look at the product information for say the Delta 5Hp 3 phase table saw, it is spec'ed to run on 208v 3 phase so no problems there. A Miller 252 MIG Welder is also designed to run on 208v. So it shouldn't be a problem for you to install this power setup and these tools in your shop.



gafftaper said:


> 2) Dumb question here. If my Dewalt sliding compound miter saw is a 120v saw, am I going to have a hard time running it on 110.
> I know I should really understand all this better. I'm certainly getting a crash course this week.



We commonly talk of US electricity as 110v, 115v, or 120v (sometimes even 130v). It is really essentially the same. If your electrical installers are saying 110v, chances are you will end up with something between 115v and 120v. 115v and 120v are really the most common, so you shouldn't have any issues with your tools there.


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## Grog12 (Aug 15, 2007)

icewolf08 said:


> We commonly talk of US electricity as 110v, 115v, or 120v (sometimes even 130v). It is really essentially the same. If your electrical installers are saying 110v, chances are you will end up with something between 115v and 120v. 115v and 120v are really the most common, so you shouldn't have any issues with your tools there.



By the same token you hear 208v talked about as 208v-220v. As a previous poster said thats within your safe range...

My own post was about 230 and above dropping down to 208 which I don't particually feel safe with.


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## icewolf08 (Aug 15, 2007)

Well, here are a few more notes that I thought of. First off, as Ship said, most commonly 208v is not single phase, it is "split phase" In that you are using two hot legs from a Y transformer to get the voltage up. In a ∆ (delta if the symbol doesn't show up) system you can get 208v from a single phase which would be a different wiring than from the Y system. The wiring for 220/240v and 110/120v and for 208v single phase would essentially be the same, hot, neutral, and ground. Whereas the 208v split-phase is hot, hot, neutral, ground.

Given that, you probably don't want to connect a device designed for 220/240v to a 208v single phase as you will definitely loose performance, and you really don't want to connect it to split-phase as it may not be designed to handle that.

The other thing I thought of for gaff is that having the 120/208v Y system in your theatre is probably the best option. It is the most common for use to connect power distros and can easily provide power for things like moving lights.


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## gafftaper (Aug 15, 2007)

Thanks everyone. I think I'm starting to understand. It's really rather insane that we don't just have one set of standard voltages in this country.


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## Grog12 (Aug 15, 2007)

gaff please edit your post to say world not country...because honestly I'm over the whole weird ass overseas voltage and plug thing. I'd gladdy accept someone elses plug if we could have a worldwide standard.


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## gafftaper (Aug 15, 2007)

Grog12 said:


> gaff please edit your post to say world not country...because honestly I'm over the whole weird ass overseas voltage and plug thing. I'd gladdy accept someone elses plug if we could have a worldwide standard.



Hey I'm willing to let Kim Jung Ill have whatever crazy power system he wants. I just don't want to deal with buying expensive power tools and not being 100% sure they will work in my shop.


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## icewolf08 (Aug 15, 2007)

Here are two graphics I just did up for the different 3-phase systems we talked about. I will put them in the wiki later on.


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## gafftaper (Aug 15, 2007)

icewolf08 said:


> Here are two graphics I just did up for the different 3-phase systems we talked about. I will put them in the wiki later on.



That's great the Wiki could use a good article on multiphase power.


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## Van (Aug 15, 2007)

gafftaper said:


> That's great the Wiki could use a good article on multiphase power.


 
I like mine. Not dissin' < wow I'm hip!> Icewolfs I just like the layout of these I found. a little bit easier to read for some newbs I've found.


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## Grog12 (Aug 16, 2007)

So Van how do you get 230v + power in the 3 phase differential? Does it start hitting +1.25/-1.25 or does it end up being a different system?


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## icewolf08 (Aug 16, 2007)

Grog12 said:


> So Van how do you get 230v + power in the 3 phase differential? Does it start hitting +1.25/-1.25 or does it end up being a different system?



The quick answer to your question is yes, you need 240v service to get 240v. So you either need to have a 120/240v delta transformer for incoming power from the main line, or you could use a step-up transformer, or you could have a 240v Y transformer (I just don't remember what your phase to phase voltage is in that case).

The measurement on Van's graph that indicates 240v is a peak to peak measurement which doesn't exist in reality. It doesn't measure and usable voltage as you don't really have voltage between a phase and itself.


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## Footer (Aug 16, 2007)

icewolf08 said:


> The quick answer to your question is yes, you need 240v service to get 240v. So you either need to have a 120/240v delta transformer for incoming power from the main line, or you could use a step-up transformer, or you could have a 240v Y transformer (I just don't remember what your phase to phase voltage is in that case).
> The measurement on Van's graph that indicates 240v is a peak to peak measurement which doesn't exist in reality. It doesn't measure and usable voltage as you don't really have voltage between a phase and itself.



Wow, we are now argueing about whos graph is better, I didn't go to business school for a reason...


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## gafftaper (Aug 16, 2007)

I barely understand either one so they must both suck... or maybe it's just me that sucks. Hmmm... yeah it's probably just a personal problem never mind


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## Van (Aug 16, 2007)

Again i wasn't running down Icewolfs. Mine simply represents the fact that the sine wave travels to both side of the 0 phase, or nuetral. Yes it's impossible to have potential between a phase and itself, However the graphs I posted show potential between the phases, which are demonstrated as being " Out of Phase", with each other, and the nuetral, which is the baseline down the center of the chart. that's all. It's a slightly different visual clue, and whereas Icewolfs is an end on visual of the same graph,essentially.


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## derekleffew (Aug 26, 2007)

icewolf08 said:


> ...
> 
> Given that, you probably don't want to connect a device designed for 220/240v to a 208v single phase as you will definitely loose performance, and you really don't want to connect it to split-phase as it may not be designed to handle that. ...



What I'm seeing more and more with video projectors designed to run on 200-240v is the use of a buck/boost transformer at the unit that takes the 208V and boosts it to 232V. 

Recently had a "nationally televised awards show" where the building power was 205-207V, 3phase, and long (>100') 12/3 cable runs were "starving" the Super Troupers, which are 220V single-phase devices. Adding buck/boost transformers brought their voltage up to 230V, and solved every problem.

Had a similar problem with SX3K Synchrolites on a another show. In my building the voltage across any two hot legs is generally 212-213. In April, when most of the county started using A/C in a big way, voltage dropped to 205-207. Nevada Power swore that wasn't true, we were mistaken. Considering we meter power after every tie-in, I think we know what we're talking about. We added 3phase 30amp buck/boost to the Synchro's, and they were very happy. Synchro's are supposed to be auto-ranging from 190-240. Oddly, the last two shows, voltage has been back up to 211-213, where it usually is. I guess Nevada Power finally found the "vitamin-enriched" hamster food.

I'm not saying you should put a buck/boost transformer on a power tool. Never done that, never needed to. I have never seen a performance degradation running a 220V single-phase motor at 208V. I would prefer a 208, 3phase table saw other large wood-working tools.

gafftaper, Sounds like you'll be fine with what's been spec'd.


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