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3 phase 480v motor with 6 leads and no schematic #193395 03/30/10 06:48 PM
Joined: Oct 2005
Posts: 141
L
LoneGunman Offline OP
Member
I have to hook up a 50hp 480v motor, the schematic is gone. The 6 leads are what's throwing me. I can make out on the tag that the motor is dual voltage. It was previously fed with 480, when it was move instead of leaving the split bolts and cutting the feeders they cut the leads instead. The six leads are numbered 1,2,3,6,7,8 or it's 1,2,3,7,8,9. I can't tell if the 6 is a 6 or if it's a 9.

None of the 6 wires were connected to each other, even though they cut the leads to remove the motor they'd have no reason to undo connection in the peckerhead that were not attached to the feeders so I'm ASSuming 1 and 7 would go to L1, 2 and 8 to L2 and 3 and 9 to L3, I'd really hate to let the smoke out of this motor if I'm wrong.

Anyone have any ideas?

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Re: 3 phase 480v motor with 6 leads and no schematic [Re: LoneGunman] #193397 03/30/10 08:54 PM
Joined: Nov 2006
Posts: 23
W
wire twister Offline
Member
If you have a copy of Uglys electrical reference it is in there, but sounds like you have it right if you want to run on 480.

Re: 3 phase 480v motor with 6 leads and no schematic [Re: wire twister] #193400 03/30/10 10:39 PM
Joined: Jun 2004
Posts: 1,273
T
Tesla Offline
Member
From Electrical Pal, pg 6-4...

Wye wound motor for 240/480 3-phase volts...

It would appear that your motor was set for 240V and the T connections were:

1 to 7 and on to T1
2 to 8 and on to T2
3 to 9 and on to T3

4,5,6 are buried down in the peckerhead, all jumpered together.

Your '6' is a nine, for sure.

To connect at 480V you'll need to pull up the 4,5,6 leads and go with:

1 to T1
2 to T2
3 to T3
AND
4 to 7 jumpered
5 to 8 jumpered
6 to 9 jumpered

As always, if the rotation is wrong, swap T1 and T3.


Tesla
Re: 3 phase 480v motor with 6 leads and no schematic [Re: Tesla] #193402 03/31/10 12:00 AM
Joined: Oct 2005
Posts: 141
L
LoneGunman Offline OP
Member
Thanks guys. Tesla, how have you been? Haven't "talked" to you in ages.

Tesla, that's what I was thinking, my father in law who's a retired maintenance electrician said the same thing. The customer swears this motor was running at 480v, I went to where they said it was hooked up and 480v is the only thing there. So either they mixed the motors up somewhere or there is a way to wire that motor for 480v with the wires I have in the peckerhead. My FIL said in 30 something years he has never came across a motor where you could run it at 480v with the wires that are in the peckerhead.

Re: 3 phase 480v motor with 6 leads and no schematic [Re: LoneGunman] #193404 03/31/10 12:44 AM
Joined: Feb 2003
Posts: 939
F
frenchelectrican Offline
Member
here the photo how this motour hook up

[img]https://www.electrical-photos.com/showphoto.php/photo/625[/img]

Hope that show ya how it run like that

Merci,Marc

Last edited by frenchelectrican; 03/31/10 12:47 AM.

Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)

Re: 3 phase 480v motor with 6 leads and no schematic [Re: frenchelectrican] #193408 03/31/10 05:17 AM
Joined: Jun 2004
Posts: 1,273
T
Tesla Offline
Member
Marc...

The leads numbering smells of a Wye winding....

It is of LG to determine which is which.

BTW is this a NEMA motor?



Tesla
Re: 3 phase 480v motor with 6 leads and no schematic [Re: Tesla] #193415 03/31/10 04:28 PM
Joined: Oct 2005
Posts: 141
L
LoneGunman Offline OP
Member
I got it, I screwed up, it was NOT a dual voltage motor so 4,5,6 were together internally, 1-9 to l1, 2-8 to l2 and 3-7 to l3.

Re: 3 phase 480v motor with 6 leads and no schematic [Re: LoneGunman] #193423 03/31/10 11:34 PM
Joined: Feb 2003
Posts: 939
F
frenchelectrican Offline
Member
I kinda figure it and it is a Wye connected motour.

I wish the motour manufacter just put in a quick note to stated that is delta or wye connected motour so we can able speed up the troubleshooting.

What I do with the motours I work on I take the stamping punch and punch either D or Y right next to the connection diagram or on pecker head one of the two.

Merci,Marc


Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)

Re: 3 phase 480v motor with 6 leads and no schematic [Re: LoneGunman] #193432 04/01/10 01:40 PM
Joined: Mar 2010
Posts: 1
J
JRobb Offline
New Member
Hi, i might be confusing the issue here a little but if the 6 leads were disconnected it implies(UK) that the motor was fed via a star/delta (wye/Delta) starter,, if so if you wire it to run in wye you will have overheating problems and if in delta excessive starting load problems,,


Re: 3 phase 480v motor with 6 leads and no schematic [Re: JRobb] #193438 04/01/10 05:24 PM
Joined: Jun 2004
Posts: 1,273
T
Tesla Offline
Member
LG, what was the driven load?

You may have to give it a soft-start intelligent controller.

Last edited by Tesla; 04/01/10 05:26 PM.

Tesla

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