I know it says wiring, but please read :)

[Tim]

As I've slowly started to replace my questionable tools with bigger/ better/faster, I've generally switched to 3 phase (table saw, planer, jointer, dp and dust collection are all 3 phase now). To this point I've just hardwired everything to an increasingly ugly panel of fuseboxes. I'll be installing a full blown 3-phase breaker panel in the coming weeks and removing all the fuseboxes, save for the main 200a disconnect. Here's the major question though: What type of outlets/plugs are generally used for 3 phase? Do most people hardwire everything? There seems to be very little if any standard 3 phase plug, and I'd be fine with my tools not being portable (who wants to load the 400lb unisaw?..). I have some hubbell plugs that came on a few of the tools (almost all bought used, almost all older than I am), so that's where I'm leaning, but they are expensive.

What type of plug/outlet would you suggest? Should I stick with hardwiring for the majority of tools and just use something like the hubbell plugs for the ones that need to be somewhat mobile? Is there some cheaper alternative?

Thanks, Tim

[Lew Hodgett]

Knowing what type 3 phase will make answering your questions meaningful.

208Y/120/3PH/4W? 240/3PH/3W? 480Y/2773PH/4W? 480/3PH/3W?

Doesn't look like you are in Canada, so forget the 575V.

As you can see, it makes a difference.

Lew

[J. Clarke]

The relevant standard is

I believe that one of the four-wire outlets (3 phases plus safety ground) is required, but I don't have the code handy. Also check your local code on the odd chance that it requires something different from NEC.

Use a plug. You want the power off to the machine whenever you're changing blades, knives, or whatever or have your fingers in the belts. The power switch alone is not enough--they've been known to fail _on_ and there's always the chance that your kid or one of his bratty friends will say "what does this do" and hit the switch at the worst possible moment. The power switch and the breaker will do from that viewpoint but using the breaker has several disadvantages:

One is that it's easy to hit the wrong breaker.

Another is that even if your shop is meticulously labelled, if you get in the habit of using the breaker as the safety shutoff then one day you'll be in someone else's shop and he'll have it labelled wrong (I've seen _far_ too many mislabelled or unlabelled circuits).

Another is that if you have to go more than three steps to pull the breaker odds are that you'll get sloppy about using it. The cord should be plugged in within six feet of the machine so that's less likely to be an issue. (note--if you're putting in outlets for the machines, place them where they are going to be quickly reachable for this reason).

Another is that the unplugged cord gives you immediate visual feedback that the tool is cold.

[Charley]

In addition to this, I would suggest that you replace your fuse panel(s) with 3 phase breakers. Using fuses on 3 phase equipment is not a good idea as loss of a phase due to a blown fuse could result in loss of the motor being powered by it. 3 phase motors don't like to run on 2 phases and the loss of just one motor could cost as much as a whole panel of breakers. 3 phase motors also each need overload protected motor starters for further protection.

Charley

[Tim]

My apologies. It's 208Y. I use the 2 120 legs for the house, and the third (stinger?) leg is only in the shop.

[Lew Hodgett]

Super, you have it made in the shade.

Get a 3PH, 4W panel board for your distribution panel.

I'd use a separate 3P c'bkr for each fixed tool (saw, shaper, plasner, etc)

Mount a 3P, non fused, safety disconnect switch on the wall within 10-15 ft of the tool and hard wire from the tool to the disconnect switch with a piece of SJO cord.

You can now padlock the safety switch in the off position when you want to work on the tool.

Since you will be operating tools that will only operate at 240/480VAC, it will be necessary to add small buck-boost transformers in order to be able to operate a 240VAC tool from a 208Y supply.

Any decent electricasl supply house will have buck-boost xfmrs in stock and can select the proper size required, if you provide the amps @ 240 VAC req'd.

Mount the B-B xfmrs at the safety switch location.

Forget about plug/receptacle for these loads, a non fused safety switch is only a more reliable installation, but will probably be less costly.

Have fun.

Lew

[Charley]

That's not 208 Y , it's split phase Delta and it's 240 V phase to phase in the USA and not 208 V . You have to be careful which phase you use when hooking up something between one phase and neutral for 120 VAC as that voltage is only available from two of the phases. 208 Y ideally has the same voltage from each phase to neutral. For 3 phase needs split phase delta works fine, but never connect voltage sensitive 120 volt equipment to it without making sure that your wiring is correct. Measure the voltage before plugging something in the first time that an outlet is going to be used. Also check to be sure that 3 phase equipment can run on 240 V before connecting it.....There is a significant difference between 208 Y and 240 split phase and some equipment cannot handle it. All 3 phase is NOT the same.

Charley

[Lew Hodgett]

What utility is still installing wild leg delta to get 120V from a

240V delta source?

Haven't seen any wild leg delta installations that don't usually date back to the late 50s.

Lew

[Charley]

"Lew Hodgett" wrote in message news:jBwGj.3657$Ew5.2811@trnddc04...

Lew,

There are more "wild leg" or "split phase" (also known as "high leg" and stinger leg") out there than there are 208 Y systems. Some electric companies prefer one over the other, but you can find both almost anywhere in the USA. There are several other methods of delivering 3 phase power, but these are the two that are most common "point of use" versions in the USA.The next most common on the list is probably the grounded leg delta system. The lowest voltage commonly available is 240 phase to phase but in this version one of the legs is grounded, so you measure 240, 240, and 0 when measuring between each of the phases and ground. You can't get 120 from this one without a transformer no matter how you try to hook up to it. The electric companies use it a lot for their main transmission lines and for delivery to larger customers who have their own transformer substations. With the right transformer you can convert any 3 phase system to whatever other 3 phase system that you need or prefer. The cost of these transformers makes doing this prohibitively expensive for a small customer, but the larger 3 phase power users do it all the time. One part of a plant might have one type of 3 phase while another will have something different. It all depends on what the needs of that area of the facility are. They will likely also have additional transformers to supply 277 V for industrial lighting requirements and 480 V 3 phase for larger machines and furnaces, plus 120 for the office areas, all supplied via trasnsformers from the main 3 phase electric service which is probably 14.7 KV 3 phase or higher.

I never realized that so many methods of delivering 3 phase power existed in this hemisphere until I began installing European made printing presses in all 50 States and the Carribean Islands. Everywhere that we had to install one of these presses it was my job to figure out what power was available at the location and then figure a way to make it power the new presses. At a few places I even had to make 3 phase power from single phase. Since these presses were manufactured to run on 220 V 3 phase Y connected 50-60 cycle, there wasn't any place in this hemisphere where we could simply just plug them in. A 208 Y service needed boost transformers to raise the voltage to

220 and a 240 Delta service needed to be converted to a Y service as well as correcting the voltage down to 220. Fortunately, the presses were designed so they would run on either 50 or 60 cycle power or my job would have been even tougher.

Charley

[Lew Hodgett]

Think I will have to take exception on that one.

I've been out of the electrical business since the early 80's; however, NONE of my electrical consultants were designing anything but Y systems, even back then.

One local utility still had some isolated locations but were phasing it out.

None of the Rural co-ops had any that I ever ran across.

The advantages of being able to create a known ground fault current when a fault occurred, thus you could deal with it in a safe way made a "Y" system a no brainer, even back then.

Still remember the Rube Goldberg schemes used by the automotives to indicate grounds in their 120V control systems.

Wire two (2), 240V pilot lights in series with the center tap grounded and the 120V control circuit ungrounded at the control x'fmr.

In the event of a ground, one of the pilot lights would go out, indicating which leg was grounded.

It worked, after a fashion, keeping those production lines going 24/7 for a lot of years.

I could understand if some of the smaller rural co-ops located out in the boonies still had some wild leg delta running, but not in a major metro area.

BTW, can relate to what a total PITA trying to install European equipment operating on 380/220/3PH/50HZ in a 480/3PH/60HZ world can be.

Early in my career, faced just that problem.

Solution was not to buy European equipment without European electrical equipment, then finish it out over here.

Lew

[Charley]

Lew,

I prefer Y systems too but, when in the installation business, you have to deal with whatever system the customer has in their location and find a way to make it work. I was the only electrical factory service rep. for North America for that European press company, so they expected me to just "deal with it" and make their product work no matter where they sold it. I also occasionally had to come up with very creative ways to correct design deficiencies in new models of the presses, while somehow keeping the customer a bit in the dark about what I was doing. Most of the time the factory was just interested in making more and didn't care if they shipped a few quality nightmares every now and then. Unless it was a total show stopper they just stuck me with figuring out how to make it work.

Charley