wiring a 1 hp motor

kevin adams

kevin adams

Joined
Apr 14, 2007
Messages
239
ok, all i know less than your average carrot about electrical wiring, figured i'd run my dilemma by the pros. I have a coote grinder that i finally got mounted to my table and a buddy helped me mount the motor in such a way that with minimal effort i can change the speed by changing the pulley. No surprises there but the motor i bought was a brand new 1 horse motor that was not wired to a cord of any kind. bought a 16 gauge extension cord lopped off several feet and then had a friend that knows slightly more than i about said topic help wire it for me. Had the motor running fine everything was hunky dory but then the motor got extremely hot and while it was running even on the fastest pulleys it was relatively slow and bogged down with very little pressure. Said friend who helped me with mounting the motor told me that the extension cord i used was too small a gauge so i picked up a 12 gauge extension cord and a new switch. If i wire it as before with the new 12 guage wire will this fix the problem???. Sorry so bloody long winded. Thanks in advance!
 
If it's a TEFC motor the enclosure is meant to get hot, the case is the heat sink and radiator and the fan blows air around the case to cool it. A TEFC motor can get up to 95°C, maybe even hotter depending on the rating.

Also, make sure your drive belt isn't slipping, this would cause excessive heat buildup at the bearing and/or drive pulley.

Another quick check to see what may be up is where the heat is being generated. with a TEFC the case should get warmer than the shaft and pulley, if the opposite is occurring, then there may be something up with the drive pully being too tight, too loose or out of alignment.
 
Last edited:
Most motors like that can be wire for hi voltage (230) or low voltage (115). It sounds like it is wired for 230, but is being run on 115.

Wiring a motor is not rocket science. There should be a wiring diagram on a plate with number or color codes. I suggest you look at this and see if what you have conforms.
 
ya if you run a motor that is wired for 23ov on 110 it will get hot.
 
As Nathan and JT said , you best check the total hook up . If it is correct then yes 16 ga. for 110 volts definitly too small . For some of us electricity is simple for others not so . Be careful make sure all connections are tight . You do not need a fire or death . 110 volts will kill you fast , well maybe slow but it is unpleasant and you are still dead .
 
I just wired one today for my Coote. You gotta check whether it is running CW or CCW. You want the belt to come down from the top. I wired my backwards the first time. Thats funny though, I did it like the diagram said, but had to reverse it. It runs like a top.
 
should have said, it is running so belt comes down from top, also it sys can be run on either 115 or 230, but ill do some further checking, gonna so see if i can wire this new cord in with minimal problem, also will check to see if gets hot without belt on. One thing cal, what hp motor did you use, and did it bog down real easy?, ill go check and post what i come up wit later tonight
 
1HP can be anything ,depending on how the rating was determined. What is the amp draw? That will tell you a lot about the motor. I think you will find a lot of cheaper 1HP motors deliver more like 1/2 to 3/4HP. It should be somewhere around 12-14 amps if it is a real 1HP motor.

Make sure it is wired for 120VAC, not 220VAC
Make sure the belt is straight and not too tight or loose.
Allow the unit to come up to speed before grinding ( 5-10 seconds)

Is the motor new or used? What does the plate say on it?
Stacy
 
bladsmth said:
1HP can be anything ,depending on how the rating was determined. What is the amp draw? That will tell you a lot about the motor. I think you will find a lot of cheaper 1HP motors deliver more like 1/2 to 3/4HP. It should be somewhere around 12-14 amps if it is a real 1HP motor.
....
Click to expand...

Good point Stacy!! I always crack up when I see the shop vac display at my local Lowes hardware store boosting "...7 peak Horse Power..."

puleeze!!! That would be about 85 amps coming out of the little wall outlet.

In reality, I'm sure it's only about 3/4hp or so...

Yes Kevin, I'm sure you've got a good motor..but as already posted, I too suspect that it has been incorrectly wired for the voltage that you are running it on. Motor name plates have all of the important info on them...and it will have notes about wire hookup.

Have fun with your new machine!

-Rob
 
bladsmth said:
1HP can be anything ,depending on how the rating was determined. What is the amp draw? That will tell you a lot about the motor. I think you will find a lot of cheaper 1HP motors deliver more like 1/2 to 3/4HP. It should be somewhere around 12-14 amps if it is a real 1HP motor.


Stacy
Click to expand...

This is true in practice, but I feel it could use some elaboration.

At 100% efficiency, one HP is equal to 746 Watts. At 115 volts that would be 6.5 amps. A typical motor might be 80% efficient due to electrical and frictional losses. So some motor delivering 1 HP at the shaft would draw about 8 amps. Many 1 HP motors are rated to draw perhaps 50% more than that for short periods of time, meaning it could work as a 1 1/2 HP motor for a few moments without stalling, overheating or damage, and might even draw something like 16 amps. Although the wires and breaker may be rated for 15 amps, the temporary 16 amp overload will not overheat the wire or flip the breaker due to the short time

The limiting factor in HP rating is generally not the power the motor is capable of, but the heat it can tolerate.


Stall torque is more important to a knifemaker than HP rating because of the intermittent loads we apply to a motor
 
Last edited:
rfrink said:
Good point Stacy!! I always crack up when I see the shop vac display at my local Lowes hardware store boosting "...7 peak Horse Power..."

puleeze!!! That would be about 85 amps coming out of the little wall outlet.

In reality, I'm sure it's only about 3/4hp or so...



-Rob
Click to expand...

Not just shop vacs. Re: the new Haas isn't really 30 HP..

... The install guy said, "Nope, that's 'Haas' power, not horse power"...

It is on an 80 amp circuit...
 
thanks all, definitely appreciate the help, ya looks like the fella wired it incorrectly. i replaced the cord with 12 guage and we re wired it. And this is why i don't mess with electricity. I like my digits where they are thank you. At any rate i hope to off to a flying stop very soon.Thanks!
 
I'm having trouble wraping my mind mind around this one, I hope you guys can help,
I have a Westinghouse 1HP 115/230 V single phase,
I want to put a spdt switch in it to reverse rotation,the wires all come out of a cavity in the side and are numbered and connected with wire nuts
on the side plate it says to reverse rotation interchange leads 5 & 6 with 7 & 8 ,
there are two capaciters 7 goes to one 8 goes to the other both are conected to 3 and 9,
5 & 6 are conected to another wire 0 or D ? ,

do I need to connect 7&8 to one side of the switch 3&9 to the center and 6&5 to the other side and what do I do with the wire marked 0orD should I wire it in with 6&5 or tape it off and let it hang.
 
You must log in or register to reply here.
Back
Top