Should I Spend $3k for 3-phase?

[Tom Vermont]

Hello,

I've tried searching, but haven't quite found a simple answer...

I am building what I would call a large garage, but most of you would call a shed, 26x38. One garage bay will be for cars, one for motorcycles, and the extra depth will be a small workshop. I will have a 7.5HP 80 Gal compressor, an EV charging station, an HD-9 4-post lift, and possibly a welding area. Way down the line, I might get a small milling machine.

There is 3-phase power running along the street. For $3k over the cost of 1-phase service, I could run 240V 3-Phase. Although no American-spec EV currently takes advantage of 3-phase charging that I am aware of, this would allow me to "future-proof" my garage for electric cars, to some degree. For $80, Bend-Pak can wire the HD-9 for 3-phase, but I'm not sure there is any advantage.

Is it worth it? I have to tell my GC what I want on Monday.

Thanks, Tom

 

[Stuart in MN]

If you intend on getting some machinery with large electric motors it would be useful. I doubt it would help in the future for any electric vehicle charging. Otherwise, for normal garage stuff (lights and outlets) I don't see any advantage.

 

[James-W]

Unless you have machines with large electric motors that run pretty much all the time, I doubt you would ever see the day when the savings equalled the cost to get it installed. I am not knocking 3 phase power, I think it is wonderful. But unless you need it on a regular basis I doubt paying an extra $3K to get it it would prove to be economically worthwhile.

 

[sberry]

You don't need it.

 

[Tom Vermont]

OK, sounds like it's a nix... I thought there were 3-phase chargers for EV's in some markets that could charge a car in 3 hours?

 

[walta]

I think 208 3 phase volts is a better choice because it gives you much better options for powering your 120 volts circuits.

Some 240 3 phase panels can run 120 v loads but it is often not ease and you get fewer 120 circuits.

Almost any new 240 volt motor will be labeled for 208.

The only down side to 208 is you lose some wattage / performance with resistive heaters. Think 208/240 V water and space heaters.

Walta

 

[walta]

Be careful if the building will have a separate meter 3 phase power may make the service be billed as a commercial account at higher rates

Walta

 

[kaffine]

While I would love to have 3 phase from the power company at my home shop the power company charges an extra $75 a month for 3 phase residential service. I don't have that much of a use for it. The kWHr charge is the same.

For the $3k you could buy phase converter or VFD if you have a need for 3 phase for machinery.

Electric cars in the US are unlikely to come with 3 phase on board chargers any time soon if ever. Other countries they do just not in the US. In order to take advantage of 3 phase to charge a car faster would require a DC fast charger setup when I looked into it they seemed to go for more than $10k. They do have single phase DC fast chargers as well though may be limited in power compared to the 3 phase options. The on-board charger in my car is 11.5kw, DC fast chargers I looked at were up to 50kw. Takes about 6 hours to fully charge at home with the built in charger, with a DC faster charger it would be 1.5 to 2 hours. Not worth the extra cost for me.

 

[Lassen Forge]

For 3 grand to me it would be a no brainer - you can do more with 3Ø, you don't know the deals I passed on because 3Ø is so prohibitive to get up here, and a phase converter, while it works, isn't as usable (or honestly as cheap) as being dropped off by the Powerco. It would allow me to use more power cheaper (even with the surcharge, which if you use enough, or have a rural farm or business, is waived, at least here...)

If you have an EV it just makes that much sweeter... All our EV chargers at work are 3Ø, and it gives you an option (if you're a publicly accessible business, and can propose it well) a Tesla Supercharger. (IIRC they're 480 or 600V 3Ø... )

 

[checkthisout]

Not needed. 3k buys a lot of stuff.

 

[ard]

I wonder what it really costs to add one wire and a 3P panel....

 

[sberry]

2 wires, 2 trannys at idle forever for nuthin. We need to re read the op, 2 car garage. It would be different if he was going in the machine shop business or running grain elevators. Or a fleet of electric taxis.
He doesn't need this.

 

[rtz]

http://www.manzanitamicro.com/news/68-new-54kw-3-phase-isolated-charger-released

Or if you have a stout solar install:

http://store.evtv.me/proddetail.php?prod=dcdcchargestation

 

[Stuart in MN]

If you have an EV it just makes that much sweeter... All our EV chargers at work are 3Ø, and it gives you an option (if you're a publicly accessible business, and can propose it well) a Tesla Supercharger. (IIRC they're 480 or 600V 3Ø... )

The Tesla Superchargers that are out in public may or may not be three phase, but their chargers for home use are not. (since you mention 600 volts I assume you're in Canada.)

Remember, we're talking about a residential two car garage here.

 

[Tom Vermont]

Thanks for all the help Gents. I've emailed my GC and told him to delete the 3-phase. I can certainly make better use of the funds elsewhere.

Cheers, Tom

 

[sberry]

Forums are great for information but they do not always give great advice. There is so much info and opinion it becomes confusing for those who are that way to start with.
Yes there is a place for 3 phase, some need it, some it would make sense for, those that want to collect used industrial equipment. I wish i had it, over the years it has been a problem but,,,,,,,,, the guy that posted this doesnt, already going to be an issue with a hoist. Modern welding equipment uses less all the time.
If he came here with the idea that he was going in the fab business and was going to stuff a place with used industrial equipment then I would be all for it, but anyone implying that it's worth it to this poster really doesn't know what they are talking about, is contributing to confusion instead of clearing it up.

 

[sz0k30]

sberry,

Whenever I see your responses to questions, you usually seem to be the voice of reason in a sea of confusion. Thanks!

 

[sberry]

I have done this so many wrong ways that it looks familiar. I have over wired, over piped way more than under, in fact never had it too small and have owned and used some of the same stuff for decades, even replaced stuff I had originally installed and can remember where I argued with the guy I asked for advice that I needed inch instead of 1/2.
I don't know a lot about real technical stuff but have experience around demand and even ran some tests on occasion to see how it all matches guesses, how much does 50 ft of 14 cord really effect a small wire welder. A little bit,,,, wide open.
Not every circuit needs to be calculated at 20A and 100 ft, most real work is done closer and not every applied load is 20. very few other than air compression and some minor welding and the duty cycle is way lower than the imagination. You can run 2 da sanders from a 1/2 line and barely notice the difference from 1 and so what if there is a blip in the max hp for a second.
Almost none of the future proofing I ever did paid out, I still have a lot of wire "parked" due to that and still tend to do it. I am way more inclined to use a power strip for extra outlets on minor stuff, same for cords. I aint got to build it in and quad wire every place I night need a convenience outlet. Don't really own anything common would actually overheat a 10 wire.

 

[sberry]

This is really my favorite aspect of these forums,,,, what is the real "demand" factor. I have never tripped a 100 service despite running hard a couple different times usually under distress. The only time I have ever suffered from pipe performance was once on a well type system where someone had put a sprinkler with a big nozzel on the same tail end as a large pressure washer. The helper running it did the right thing, shut off the washer and stopped work to let a lawn sprink run,,,, ha but only did it below cut on pressure which was low anyway.

 

[sberry]

I became operators of a system vs just seeing how much I can imagine being pigged thru it. I found out that it doesn't hurt to zing a board off with a 100 ft 16 cord from good service, doesn't ruin my saw I have had for 30 yrs. and now barely use.
There is a big difference in load types as to weather its irrelevant or not. I need a better cord for 100 of run for a cutting station for air comp and heavy saws than I need for a couple minutes with a leaf blower of few seconds a time for a circ saw for maintenance work.
Voltage is 10% higher than when some of these standards were created, where there would have been drop with 5 gpm for a toilet now 1.6 over the same line, not only do you not need a line bigger than was used 25 years ago can add 3 more to the same service and not notice them. Not only that but some resistance keeps the pressure in the rest of the system a little. H4ence sink and toilet supply tubes instead of full port laundry valves.
I was on the job and my Bud cam back with lots of 4 inch for internal work and a rehab,,, I caught him and said, go back for 4, works better.

 

[sberry]

I am concerned but try not to be a perfectionist contrary to some pop[ular belief but one of the things I do is got no probolem replacing old infrastructure, I don't need a lot of excuse to replace an old wire or panel. I don't care if it is legal if humanly possible will pull a new 4 wire fo0r appliances or replace any old ungrounded cable I can.
I did a lot of work I didn't do right. I have seen a lot of air comps installed with 10 cables and 30 breaker work fine for nearly forever, never 1 make the wire hot or cause any damage to it. I can think of a few more embarrassing things I did that never result in failure, some not real bright and lucky.

Most of the risk is outright human error rather than a real issue with lack of utility demand.

 

[930dreamer]

My shop is in a commercial location so I'd consider the 3 phase install.

 

[sberry]

No one is saying you don't plan for demand but I must have wired a couple dozen service to garages, never had one trip a 60 or call me for an upgrade or poor performance from a number 2 aluminum wire.

 

[kaffine]

For 3 grand to me it would be a no brainer - you can do more with 3Ø, you don't know the deals I passed on because 3Ø is so prohibitive to get up here, and a phase converter, while it works, isn't as usable (or honestly as cheap) as being dropped off by the Powerco. It would allow me to use more power cheaper (even with the surcharge, which if you use enough, or have a rural farm or business, is waived, at least here...)

If you have an EV it just makes that much sweeter... All our EV chargers at work are 3Ø, and it gives you an option (if you're a publicly accessible business, and can propose it well) a Tesla Supercharger. (IIRC they're 480 or 600V 3Ø... )

Do you happen to know what type of EV chargers they are?

 

[wyliesdiesels]

I think 208 3 phase volts is a better choice because it gives you much better options for powering your 120 volts circuits.

Some 240 3 phase panels can run 120 v loads but it is often not ease and you get fewer 120 circuits.

Almost any new 240 volt motor will be labeled for 208.

The only down side to 208 is you lose some wattage / performance with resistive heaters. Think 208/240 V water and space heaters.

Walta

Not sure what you mean here.

If the panel has a neutral bus, then it can serve 120v loads. Just dont hook up 120v loads between the stinger/hi leg and neutral.

Pretty rare to find a 240v only panel.

 

[Bretny]

The air compressor is the only thing that may require 3ph. But at $3k you can buy 2 240v 60gal...

My father had 3ph in his garage/machine shop. They were charging him about $120 a month just to have acess to the power. He cut the service off.. he had 2 mills, a cnc, 2 surface grinders and a lathe all 3 ph. This was after about 2 yrs of closing his business so the machines sat idle. You can do alot with a phase converter.

 

[matt_i]

I'd also recommend a phase converter. The beauty is that if life changes suddenly and you move, you remove the installation back to the single phase panel and take it with you to the new location, instead of paying for another utility install.

Utility 3ph can come with demand charges, the panels and breakers get way more expensive, and there's the responsibility to try to balance single phase loads across the 3 legs.

 

[tdcisco1]

google; demand meter. At work we switched to 3ph, great thing to have,the demand bills are a bit salty tho. For our use single phase would suffice.

 

[Lelandwelds]

I love bargain used industrial equipment. I like the better arc and some of the advanced features from 3 phase wire machines.

With the extra charges the utilities impose today, I would pass on the three phase. Thirty years ago the monthly cost was minor. Today, I'll pass.

 

[wyliesdiesels]

Be careful if the building will have a separate meter 3 phase power may make the service be billed as a commercial account at higher rates

Walta

Around here, 3 phase power is actually cheaper per KwHR. But there is demand charges and TOU rates which makes the bill higher than residential.

 

[nsula_country]

Not sure what you mean here.

If the panel has a neutral bus, then it can serve 120v loads. Just dont hook up 120v loads between the stinger/hi leg and neutral.

Pretty rare to find a 240v only panel.

I believe they tried to imply only 2/3rds of the panel are useable for 120v loads.

CT