I have a li-ion battery with good bms to prevent overcurrent. I figure out to make so called long (would short be better ?) cumulative compound winding for a dc motor.
I know that in principle I must have thick series field winding and smaller diameter shunt winding.
I have 72 volts li-ion battery which can output lot of amperes.I have NTC thermistors for 50 amperes continious current. Inrush current could be high and I think that with this high voltage I can use perhaps 11 gauge ( ?) wire (2.3 mm diameter more familiar unit to me) about roghly 25 foot for armature winding (3 pole armature) because inrush is short time not continious and thick series field winding.

My question is: what would be roughly suitable lenght and diameter or gauge of long shunt field wire?
Easier and not important queston is series field lenght and diameter.

 

My question is: what would be roughly suitable lenght and diameter or gauge of long shunt field wire?
Easier and not important queston is series field lenght and diameter.

Even easier question would be - how high is up? You are the one designing this so you need to use YOUR parameters to decide. It can't be done by us guessing what you need.

 

Even easier question would be - how high is up? You are the one designing this so you need to use YOUR parameters to decide. It can't be done by us guessing what you need.

very clear statement. One thing is not clear. You must be an official represantive of a group us, which is this us?

 

You must be an official represantive of a group us, which is this us?

Most of the regular posters here. I'm not official of anything what soever.

 

This line of talk (initiated by you) is hardly most fruitful. Anyway, my experince is that most people are willing or even happy or proud to share their experinence and knowdelge. I was just asking some rule of thumb coming from experience. Minority of people are thinking that sharing knowledge takes this amout of knowledge away from them. You should know that it is not good to talk on behalf of others (using us) better to use I or me.

 

I think the point SB is making is that you have supplied no details of the motor. Is this a motor you are rewinding ? I do not have the knowledge to design a motor but I realise that to calculate winding information you would need to know many details such as motor speed, motor output power, magnetic properties of the laminations, size and shape of the laminations and probably other things. I don't understand how you have come to the conclusion that a compound wound motor is the most suitable design to meet your requirements.

Les.

 

This line of talk (initiated by you) is hardly most fruitful. Anyway, my experince is that most people are willing or even happy or proud to share their experinence and knowdelge.

Do you (if you didn't already know what your building) truly think an answer could be given for the question in your first post? If so your a better man/woman than me. Asking me or any member here to guess the size and scope of your project from the first post is not doable, at least by mere mortals.

Designing anything electrical by guessing and comparing to "normal" values used is a failure waiting to happen. If you have a motor or several motors of different sizes try measuring the values and see how far that gets you.

I do like sharing knowledge and expertise, that's why I come here all the time. And complaining about me using the term"us" is ridiculous, or your not an English as first language speaker which might explain the rebuff.

Trying to start a disagreement or argument with a member of a forum, me or anyone here, is not going to make you look good or get you any help.