motor blown

[recore]

Hello,
My brother in law asked me to move a 3 phase switch for a saw dust vacume at his factory. Im an electrician but I dont have much experiance with motors. I said no problem (how hard could it be, its just a switch) Well now the motor does not work anymore. I dont know what happened. its a 3 phase motor. He has a high leg in his panel, maybe I mixed them up and this is the problem. Honestly im clueless. Also, after that one burned up I put in a rec for a single phase vacume he had laying around (I made sure not to use the high (208v) leg, but this one seemed to burn up too. I did not connect the ground thinking that the box would ground it, could this be the problem? This situation is turning into a nightmare can someone please shed some light on this situation.

 

[bphgravity]

Re: motor blown

I think it may be advisable for you to get a more qualified and trained electrician for the work being performed. You are doing an aweful lot of supposing, which is not the best mindset when installing electrical systems.

This is not meant to offend you or call into question your qualifications. I consider myself a very qualified and trained electrician, yet I am completely aware of the particular installations I have not obtained the adequate education and experience for.

 

[charlie b]

Re: motor blown

I have to agree. We all have our limitations.

For my part, I could not begin to help you, without first asking a hundred questions. I would need to see the one-line diagram and the panel schedules for the panels from which you took the power. I would need to know about the wires you selected, the conduits or other raceways you use to route the wires, and the points of connection at each end (especially the equipment grounding conductors and the single-phase circuit?s neutral conductor). I would want to check the panels for internal wiring errors (e.g., grounds and neutrals mixed), and to check the voltage present at the two components that burned up. But I am an engineer, not an electrician. So all I could give you is a probable cause of the failures.

An electrician who has experience in motors could do all of the above, and more, and could learn the cause of the failures (not just the ?probable? cause), in a few minutes of walking about the factory. I think your brother-in-law needs to spend the money to have the job done over, this time by an electrician with motor experience. I also think it would be worth your time to watch and learn from your fellow electrician.

 

[recore]

Re: motor blown

is there anybody out there?

 

[charlie b]

Re: motor blown

Originally posted by recore: is there anybody out there?

What do you mean by this question? You have had two reasonable replies. Are you not satisfied with what has been posted so far?

 

[recore]

Re: motor blown

disregard the last message my computer just updated the poll.

Thank you for your advice, although it does not help me specifically. I think I will take your advice. I guess sometimes you just have to accept that you can't do everything, no matter how much you know, you never know everything.

But for my own personal knowledge, do you know of any good books on motors that might help me expand my knowledge?

 

[recore]

Re: motor blown

why would the type of conduit be important?

 

[recore]

Re: motor blown

Im sorry Charlie B, this is the first time I have ever used this message board and I didn't know How to refresh. So when I came back to my computer this evening there was nothing there.
I did not mean to offend you.

 

[hurk27]

Re: motor blown

Recore to allow an easier way to keep up with topics in all the threads here is a link that you can click then just save the page to you favorites
Then copy it out of the favorites folder and paste it to your desk top. It makes keeping up with all the topics allot easier:

Mike Holt Code Forum

And here is your most recent post that you can save also as above, to keep up with all you have posted:
Recent post by Recore

[ November 25, 2004, 02:58 AM: Message edited by: hurk27 ]

 

[recore]

Re: motor blown

thank you hurk

 

[charlie b]

Re: motor blown

Originally posted by recore:This is the first time I have ever used this message board and I didn't know How to refresh.... I did not mean to offend you.

I was not offended, but merely confused. Please be assured that you are most welcome to participate in this Forum. I believe that, as an engineer, I have learned more from the electricians on this Forum than they have learned from me.

You can "refresh" in two ways.

First, use the "refresh" feature of your Internet browser. I almost always type my comments in a separate Word document. Then I copy and paste the comment onto the Forum. Sometimes, when I am ready to post a comment, I hit the browser's refresh button immediately before posting. That way, I can tell if anyone else has already answered the question, or if my answer would be a duplicate.

Secondly, you can select "my profile" at the top of the page. On the upper left, select the line "Update New Post Indicators." That resets the entire list of posts, so you can see what items have been recently posted.

 

[spsnyder]

Re: motor blown

Sorry to disagree with you Charlie B, but I think I alone have learned more from you than you could have learned from others . Thanks for your continued insights.

 

[midget]

Re: motor blown

Why would you want to look at the conduit/raceways the wires where ran threw, Charlie?

 

[bgisborn]

Re: motor blown

Recore, I haven't seen your service so be careful with my advice.

I have some questions.
Does one of the legs have orange tape on it?
Do you see 4 conductors in the feeder?
Measure the voltages leg to leg and each leg to ground.
Now, before I go further. You say this 3 phase motor has a switch?
Normally a 3 phase motor has a starter. The starter is actuated by a sp momentary switch's control voltage.
You can "switch" a 3 phase motor by breaking only two legs but I hate this method. Anyway, such a switch would have to have 2 poles.
Regardless of what you saw at the service there should only be 3 wires to the motor. My guess is that you have a feeder with a wild leg. Don't worry about this. Just try to find where the starter is. I suspect you tripped the overloads.
As a reult you have no control voltage. Unless you screwed with the feeeder or starter you should be able to wire the the motor ACCORDING TO THE WIRING DIAGRAM on the motor unless you see 3 and only 3 leads from the motor. After wiring, check your rotation. If wrong, change any 2 motor leads that you have just connected. I hope that's clear.

Bob

 

[bgisborn]

Re: motor blown

Recore, if you tried to wire this motor from scratch and have only installed a "switch" to control it. Please find an electrician to help you. My last post assumed that there was a motor control in place and that you were just moving the assembly. Please do not put this motor in without a properly wired motor control. You could kill someone. I revisited your post and this thing with the "switch" has me really worried.

Bob

 

[bowman]

Re: motor blown

switch? how many wires at the "switch" what voltage..... maybe accidently took the stinger to the coil and burned the coil/ trans??????

I agree w/ previous posts need a clearer picture of whats there