(new) Dayton 3/4HP, 3 phase motor

HMH

Heath Hendrick
Senior User
Clearing out some of the unused equipment in my shop, and came across this surplus motor. I originally bought this to power an OWWM lathe, to be paired w/ a VFD to provide electronic speed control vs. moving the belts around all the time, but ultimately went a different way there. New and unused.

For those unfamiliar, a 3 phase motor such as this can be powered by regular single-phase (though 220V) residential power when paired w/ a Variable frequency drive, (VFD), which in this HP range should run ~$100 or so. The benefit here, is that for equipment w/ variable speed needs, (lathe, drill press, etc), the VFD, can also provide variable electronic speed control. I'm not an electrician, but have several VFD's in my shop for this exact purpose, and they are not that difficult to setup if you're moderately inclined.

3/4HP, 3 phase, 1140 RPM, 220V

A nice quality motor if you can use it.

CLAIMED, picked up at my home in Sanford, or my office in the RTP/ Brier Creek area.
 

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charlessenf

(;harles
Senior User
"to reverse rotation interchange any two line leads"
1736705363746.png
Do you know what that means?
For instance, using a 'low voltage' diagram, does one simply connect 1 to 8 and 2 to 7?
Thus, in the 'High Volt Conn' 'we connect 8 to 4 and 7 to 5?
Just curious at this point as I have no VFD on hand. Like to learn something new each day.
 

bowman

Board of Directors, Webmaster
Neal
Staff member
Corporate Member
With 3- phase, you have 3 hot leads providing power. It's been 40 years since i last touched 3-phase, but if i remember correctly, you swap wires 1 & 2, regardless of low voltage or high voltage. The difference is where the jumpers are. Low voltage 3-phase is typically 208V, high voltage in this case is 480.
 

charlessenf

(;harles
Senior User
With 3- phase, you have 3 hot leads providing power. It's been 40 years since i last touched 3-phase, but if i remember correctly, you swap wires 1 & 2, regardless of low voltage or high voltage. The difference is where the jumpers are. Low voltage 3-phase is typically 208V, high voltage in this case is 480.
There are NINE (9) contact points. In the illustration on the motor, the rotation is set in one direction and the connections to accommodate either of the two acceptable voltages is accomplished by connecting 7, 8, & 9 to either 1, 2, & 3 or 4, 5, & 6 respectively.

In this context "swap wires 1 & 2" is ambiguous. As well "The VFD does reverse for you" in non-responsive. "Wires" aren't mentioned. Instead we have 'Line' 1, 2, & 3. Which, in this case are leads from each of the three phases, no? Are you saying that LINE 1, represents Phase One, LINE 2, Phase Two and LINE 3 Phase Three and that connecting LINE 1 to the 2nd connection (Labeled 2) and LINE 2 to the First connection (Labeled 1) switches the direction of the motor?
 

bowman

Board of Directors, Webmaster
Neal
Staff member
Corporate Member
quite simply, wires=lines=phases.

For low voltage connections, lines connect to points 1, 2 & 3. Points 1, 2 & 3 are hard jumpers to points 7, 8 & 9.

High voltage connections (480V) have the leads connected to points 1, 2, & 3. Here, the hard jumpers are from points 7, 8, & 9 to points 4, 5, & 6.

The internal connections from tap points 7,8,9 represent different points in the armature windings for the motor.

When not using a VFD, if you need to change the rotation of the motor, you would swap 2 of the 3 wires. You could swap lines 1/2, 2/3, or 3/1. It doesn't matter which pair.


 

JNCarr

Joe
Corporate Member
Here's what's happening in the motor. This diagram is for the high voltage arrangement. You can see there are two sets of winding in series for each of the three phases. Example in Line 1 the current flows into (and out of on the next half cycle) T1 then from T4 to T7 then to the common. The higher voltage gets divided between the two coils. For the low voltage the two coils are arranged in parallel rather than series. So each coil "sees" the same voltage as before, but now the current gets flows through both coils independently.

As the name implies there are three different sets of voltages separated by 120 (360/3) degrees of phase angle. The relative timing of the phases dictate which direction the motor turns. So to change directions, swap any two wires ONLY at the point the "Lines" enter the motor (i.e., L1, L2, L3). The other connections remain exactly as shown for whichever voltage you choose.

1736714579678.png
1736715010426.png
 
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charlessenf

(;harles
Senior User
"Clearly," he wrote " if the orange phase were swapped with purple phase the rotation would be opposite."

Some things, I suppose I'll have to take on faith as they passeth understanding!

At least I know which wires to swap to change direction. Someday I may grasp why/how it works.

hanks for the links and splanations!
 

HMH

Heath Hendrick
Senior User
Well this thread grew some legs on a tangent, ha, (no worries there at all of course). Bumping up for anyone can use it. Cash works, but so does interesting/ figured boards, etc if more convenient/ appealing. Just nudging this back up to the top of the stack before I find another hole for this and forget I have it again, ha.
 

Mike Davis

Mike
Corporate Member
I would take you up on the trade if you’d like to bring it to my place and look through my lumber stash.
 

HMH

Heath Hendrick
Senior User
Hi Mike! Unfortunately I don't see myself getting up your way anytime soon, but if there is anyone in the Raleigh area headed your way in the foreseeable future, I'd be glad to pass it off to them, and you and I can just square-up later, or better yet just consider it a pay-it-forward situation - I'm sure you're already doing far more than your share in that regard.
 

Mike Davis

Mike
Corporate Member
Your profile says Sanford. I may be passing through Raleigh in a couple months or as you say someone may be headed this way. I’ll try to pm a few photos to see if you have any interest in some things I need to move out of the shop.

Thanks
 

HMH

Heath Hendrick
Senior User
Sounds good Mike - I'll consider this "yours", and will squirrel it away somewhere safe in the meantime - certainly reach out if you're ever in the vicinity, or I'd be happy to pass off to someone else to get it up to you.
 

woodlaker2

Ray
Corporate Member
Here's what's happening in the motor. This diagram is for the high voltage arrangement. You can see there are two sets of winding in series for each of the three phases. Example in Line 1 the current flows into (and out of on the next half cycle) T1 then from T4 to T7 then to the common. The higher voltage gets divided between the two coils. For the low voltage the two coils are arranged in parallel rather than series. So each coil "sees" the same voltage as before, but now the current gets flows through both coils independently.

As the name implies there are three different sets of voltages separated by 120 (360/3) degrees of phase angle. The relative timing of the phases dictate which direction the motor turns. So to change directions, swap any two wires ONLY at the point the "Lines" enter the motor (i.e., L1, L2, L3). The other connections remain exactly as shown for whichever voltage you choose.

View attachment 233951View attachment 233952
This thread reminds me of why I don't "fool" with electricity.
 

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