Wiring up motors.

[rjmockster]

I'm no expert electrician or anything but I was asked a question by the maintenance manager today at a job I'd just started with (industrial maintenance mechanic). He ased me how I would wire a motor, I replied "a layer of fiberglass tape, rubber tape, then vinyl tape over a crimp cap". He seemed surprised with my answer and then said "what if the motor is over 50 R's"? I could'nt answer that one, I guess I just don't remember ever using the slang term "R's". Can you tell me what he's talking about? I'm sure it's a simple question but I really don't know! I would really appreciate it if some one could tell me what he was referring to when he used the term "R's" in relation to wiring up an electric motor.

 

[shaun]

Re: Wiring up motors.

the only thing that I can think of is "rpm" And his first question (in my opinion) was about how you would phase the motor. For example, L1=black wire, L2=red wire, L3=blue wire and white is your neutral and green is your ground. that is for a 3-phase low voltage motor. Hope this helps

 

[luke warmwater]

Re: Wiring up motors.

Motor would be rated in HP (horsepower).

R's?? maybe, 50 ohms?
Maybe he's talking about a 1ph, resistance start?
If so, the answer would be: connected in series with the starting winding.

Now, if he wanted the correct winding connections then:
Y motor=
HIgh Voltage 6-9 5-8 4-7 3-T3 2-T2 1-T1
Low Voltage 6-5-4 9-3-T3 8-2-T2 7-1-T1

Delta Motor=
High Voltage 4-7 9-6 8-5 2-T2 3-T3 1-T1
Low voltage 4-8-2-T2 9-5-3-T3 6-7-1-T1

You shouldn't have a neutral for the 3ph motor.

If he liked your answer, with cambric tape etc., then maybe he wanted to hear that you would use Polaris taps inside the "motor terminal connection box." (Moderator's note: Edited to replace a crude slang term with one that sounds nicer.)

[ April 18, 2004, 09:23 AM: Message edited by: charlie b ]

 

[bennie]

Re: Wiring up motors.

If this man has a motor over 50 R's, offer him a trade off of 50 B,s and look for another job.

 

[charlie b]

Re: Wiring up motors.

Or here?s a novel and bold approach: Ask him what he meant by ?50 Rs.?

 

[iwire]

Re: Wiring up motors.

Originally posted by charlie b:
Ask him what he meant by ?50 Rs.?

No, to easy.

 

[luke warmwater]

Re: Wiring up motors.

Originally posted by luke warmwater:
"motor terminal connection box." (Moderator's note: Edited to replace a crude slang term with one that sounds nicer.)

Sorry, Charlie. So used to it, I didn't realize it.

 

[tom baker]

Re: Wiring up motors.

I don't promote products, but there is one that I like for motor terminal connection called Motor Stub Boots by T&B. They are rubber boots that slip over the motor leads, and can be reused. one for 4 AWG is about $8.00 each, so is very cost effective when compared with split bolts, tape and labor.
Go here to see them:
http://elec-cat.tnb.com/tnbcat/tnbcat/webcat_search_results_dsp2.build_part_home_page?p_catalog_code=SHRK&p_category_hier_id=SHR66&p_part_nbr=MSC8&p_search_indic_flg=T

[ April 18, 2004, 06:40 PM: Message edited by: tom baker ]