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07-23-2006, 12:28 AM #1
I am trying to wire up an old bridgeport M-model. It has a 1/2 HP 220/440 3 phase motor. It appears to be set up to run on 440V. I purchased a static phase converter from Grainger Supply. I understand the wiring and function of the phase converter. However when I opened up the Square D start/switch box on the mill it has a motor starter and coil that I do not understand.
The coil is clearly marked 440V. and it's removeable. Do I need to replace the coil and starter with a 220V unit. I also don't no how to switch the motor wiring from 440 to 220. I'm a lost ball in tall weeds. Can anyone help me?
Thanks in advance!
07-23-2006, 10:46 AM #2
As for the wiring from 440 to 220, that is not as big of a deal as you might think. Pull off the cover "cap" from the motor itself. THis will give you good access to the wiring. All of the wires that are used to make the 220/440 switch should have little steel bands or plastic bands around them. They will be labeled: L1, L2,.... or something like that.
Now, look at the cap you removed covering the motor. There should be a small plate with a wiring diagram on it. One diagram will be for 220 3ph and the pther will be for 440 3ph. Follow that to determine whether or not yours is wired for 440 or 220. If it needs tobe changed, simply wire according to diagram. It will only take a couple minutes to change the wiring to fit your needs.--Grant
07-23-2006, 11:41 AM #3
A two-voltage three-phase motor has three external leads, and six to twelve internal leads (a single speed motor is assumed here).
The external leads are always connected to the motor's T1, T2 and T3 leads.
The motor's nameplate may show the various connections. Otherwise there may be a connection diagram within the motor's connection box.
A static converter is a "three terminal" device. Two of those are connected directly to the motor's T1 and T3, and also to the line's L1 and L2. The starting lead (which is usually specially identified) is connected to the motor's T2.
Should the motor start in the wrong direction, interchange the connections to the motor's T1 and T3 leads, while maintaining the other connections.
07-23-2006, 02:56 PM #4
07-23-2006, 03:30 PM #5
at the Bridgeport school i was taught this.
the white man is first L1
the red man is next L2
the black man is next L3
and green goes to ground.
i hope this helps...jim
07-23-2006, 06:06 PM #6
"And my stater reads 440 Volt."
Then your coil likely needs to be changed to 220 volts.
Or, use a small 220:440 control transformer to step up the incoming 220 single-phase to 440, just for the coil.
In this case, the transformer would be on the load side of the machine's disconnect, and before the machine's "three wire" control station.
07-24-2006, 11:19 PM #7
To all thank you for the information...it was very helpful.
I changed out the starter coil to a 220 volt unit and I have determined that I need to run L1 and L3 to the phase converter. I also need to change my motor wiring from 440V to 220 V. I see the wiring diagram on the motor but now I can't figure out how to wire the forward/reverse/stop switch back into the 220V configuration. Any help would be appreciated.
07-25-2006, 09:56 PM #8
Just wanted to say thanks to all for the help on electric. I fired on my 1949 M round ram tonight and she ran sweet and is tight as can be. I used a static phase converter and have no problems with power. I played with it for about an hour cutting on some 1/2 plate I'm a very happy man.