3 phase care and feeding of older motors

[hex]

Hi all,

After moving I am finally getting my woodshop reassembled. The new space is in a pole barn at the new place. The pole barn has negligible power but I want to rearrange the power feed anyway. New feed will have the main breaker in the pole building and from there I will distribute to house etc. The electric company has said they would set a new transformer and my cost for that would be reasonable (basically running wire from pole underground to transformer and it's short run). So far so good. Across the road is 3 phase. I am investigating the cost to get 3 phase added into the move. So here's my question to the wreck: 120/208Y or 120/240 with a wild leg? Power company will provide either.

I have a couple of older pieces (example: a WWII vintage Buffalo drill press) that have been retrofitted with single phase motors. Am always looking to pick up old machines cheap. I still have the original motors and would like to put them back (freeing up the retro- fit motors for other uses). The original drill press motor says 240V, as it originally ran in a 240/415Y facility. I'm willing to lower my expectations for motor power if I go with 208Y, but I do worry about starting torque and premature motor death. Any real experience out there on this?

Thanks!

hex

-30-

[Lew Hodgett]

You mean there is still some place that will provide wild leg delta?

By all means, 208Y/120/3PH/4W/60HZ, it is safer.

Use buck/boost xfmr's for the 240V equipment.

Lew

[Swingman]

One of my subcontractors showed up with a strange looking rig/motor in the back of his truck the other day that he uses to run/test 3 phase motors from three wire, single phase locations, like my shop and his.

Basically it involved the use of an old throw away motor.

It's probably a pretty common practice for guys like you, but was the first time I'd seen the method/trick ... pretty slick!

(I'm easily impressed these days ... the older I get the less I seem to know!)

[Lew Hodgett]

You probably know more than you think, but if you are like me, just don't give a hoot anymore.

As the old German used to say, "The further I go, the behinder I get".

Lew

[Roy Smith]

Sure. My yacht club has a wild leg feed from Con Ed. The (3-phase 10 HP?) motor that drives our marine railway runs off it (as far as I know, it's the only 3-phase load in the whole place). The first time I put a volt meter on it, I was scratching my head.

No clue when the service was installed. My guess is it's got to date back to the 30's. Some of wiring is pretty scary.

[Lew Hodgett]

10 HP?) > motor that drives our marine railway runs off it (as far as I know, it's > the only 3-phase load in the whole place). The first time I put a volt > meter on it, I was scratching my head. >

An existing installation from way back when I can understand, but was aware that new installations would even be offered.

Lew

[hex]

I wasn't aware that you could get the delta either until the lady at the office read down her list of available voltages. The field guy from the power company was out yesterday so we could hash out actual costs etc and confirmed either delta or wye is possible for them, though 208Y would be slightly preferable.

So now I have to figure out how much of a cheapskate I am. 3phase overhead is only a little more expensive than single phase underground (and the power co's rule is that single phase has to go underground since it's classed as residential service and the goal is to cut down on tree trimming costs at residences) 3phase underground w/ ground mounted transformer get's me for a $450 more. SWMBO thinks that poles are ugly. I don't particularly care for poles, but on the other hand, the pole provides a place to put the night light and the "watch out for the transformer" issue when plowing snow goes away.

Thoughts?

hex

-30-

[Lew Hodgett]

IMHO, it should be a LOT more preferable.

Whether you go overhead or underground is a personal issue.

208Y/120 is much safer than 240 Delta, especially when you throw in the wild leg connection to get 120 service.

Sounds like you live in an area where security lighting might be an issue.

Better to have a light mounted on a utility pole than the house IMHO, but then again, that is a personal issue.

Bottom Line...........................

208Y/120 anyway you can get it.

Underground has a lot to offer, especially when it is time to sell.

You might be able to negotiate with the utility, but I doubt it.

After all, whether overhead or underground, there are costs involved.

Have fun.

Lew