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View Full Version : Motor label says 1HP and 12A?



CCWKen
09-09-2005, 07:35 PM
I just got a drill press yesterday and the motor says 1hp. It also says that it's 12A @ 120v. Whut up wit dat? Yea, I know it's a Harbor Freight but for $150 I couldn't resist.

Isn't that closer to 2 horsepower? Are motor ratings starting to go the other way now? Harbor Freight is now listing a replacement motor at 3hp and the ad says it's the same motor that compressor manufacturers list as 5hp. Is HF starting to "get real" with their horsepower ratings?

Oh yeah, here's the DP:
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=43389

[This message has been edited by CCWKen (edited 09-09-2005).]

meho
09-09-2005, 07:42 PM
Maybe it's just a 1 HP motor that is so inefficient it uses as much power as a 2 HP one http://bbs.homeshopmachinist.net//smile.gif

Forrest Addy
09-09-2005, 09:25 PM
Don't get fooled by overzealous applications of the 746 Watts per HP formula.

12 Amps is about right for a 1 HP motor. Small motors (1 HP IS small in the scale of these things) have large power factors leading to large seeming Amp numbers on the lable plate. My Marathon and my Baldor catalogs both show 12 Amps as a typical figure for single phase 1 HP motors connected for 120 Volts.

Asian motor makers sometimes skip a vital step. Open your motor up and see if the stator windings are dipped and baked into an immivable mass. If you can separate the individual wires with a questing thumbnail the motor needs to go to the shop.

It may last without the dip and bake but sooner or later the windings buzzing against each other will chafe through the insulation and short, frying the motor. Spend a few bucks now and save replacing the motor later. No, it does no good to bitch at HF. They're only minimum wage employers and importers of cheap stuff.

Bill Pace
09-09-2005, 10:09 PM
I too bought this drill press after seeing the price and looking at the tool. I cant comment on your query about the motor as I replaced my motor within a few days with DC variable speed. What I wanted to comment on is my most favorable impression of this machine. I've now had it about 6 wks and used it a fair bit, and doggone if it just aint a real nice machine. Fit, finish, tightness, appearance, etc, ---- I'm just very pleased with it.......I hope you will be too.

P. S.
Do as Forrest suggests and dump that orig motor, I think the chinese are maybe cleaning up their act a bit on fit and finish , but their motors still suck. I went with a treadmill motor & controller, off ebay, and got about $75 in it and an EASY convert.......sure is sweet too.

Bill

J Tiers
09-09-2005, 10:34 PM
You can figure on about 50-60% efficiency in VA for motors.... cheap ones, anyway.

Yeah, chinese motors seem to suck. They have a real problem making things per the spec, at least the cheaper vendors.

We have some SMPS transformers wound over there. Getting them to use wire with decent insulation is hard. You look at their wire, and the insulation is so thin it seems hardly there...

We specify double-coated magnet wire, and three layers of kapton tape in certain places.

Samples come back with super-thin clear insulation, and single layer tape. We complain, they agree. Then later we find them right back to the old way after making the parts right for a while.

We specify vacuum dip varnish. I think they use a paintbrush, because inside the transformer there isn't any varnish..... Same deal.


[This message has been edited by J Tiers (edited 09-09-2005).]

Lee Paul
09-10-2005, 01:44 AM
<font face="Verdana, Arial" size="2">Originally posted by Forrest Addy:
.


If you can separate the individual wires with a questing thumbnail the motor needs to go to the shop.

</font>

Forrest, I'm presuming that your recommending that the motor be "repaired" or otherwise "improved" by recoating or redipping the windings. Just out of curiousity, what "might" the cost be for such an operation.

I understand that the costs will vary based on many circumstances. Least of which is the amount of repair required. I'm just trying to get an approximate handle on it, for ballpark purposes.

Thanks..........

Forrest Addy
09-10-2005, 02:49 AM
The few times I had an otherwise good Asian motor dipped and baked I handed the man a clean bare stator and he dipped it and baked it for $20 on condition he could fit it into a batch. If your time is short or you hand him a whole motor so he has to do the assy/dssy expect to pay more.

The varnish is simply that: a baking varnish that's quite fluid. When the item is dipped into the varnish and allow to soak overnight the stuff impregnates the windings. Then it's allow to drip for a few hours and then baked into waht amounts to a rigis mass.

Insulating varnishes vary widely depending on insulation class. The motor guy will check the label plate before dipping but it wouldn't hurt you to check for yourself and bring up the class of varnish when you take in your motor.

Lee Paul
09-10-2005, 07:49 AM
Thanks Forrest,

I'm guessing the "field" windings would need additional protection also, but your explaination gives me some reference to (at least) approach the issue with.

Obviously, I'd need to contact the "shop" and find out for sure.....

Regards......LP

jimmstruk
09-10-2005, 09:57 AM
Hi, Check a real catalog on electric motors such as Grainger and note the amps draw on a quality motor running on 120 volts. Many 1hp motors draw 10+ amps on a 1750rpm rating JIM