Re: [CAD_CAM_EDM_DRO] Re: Wire Size for BPT Steppers

Hi Marty,
RE twisted pair wiring. The twisted pair only does some good if the
wires are carrying opposite and equal currents. This is true enough for
pairs connected to single motor winding, i.e. bipolar connections. For
unipolar you want either 3 wires twisted or a twisted pair for each half of
the winding. With that said the wires do not have to be twisted IF no low
voltage signal wires (SUCH AS LIMIT SWITCHES) run near and parallel. The
bigger the wire the better so use the recommendations below and the finer
the strand in the wire, the better since this improves flexability and
improves the very high frequency characteristics.

----- Original Message -----
From: "cnc_4_me" <cnc4me@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Wednesday, July 24, 2002 3:28 AM
Subject: [CAD_CAM_EDM_DRO] Re: Wire Size for BPT Steppers


> --- In CAD_CAM_EDM_DRO@y..., "Marty Escarcega" <escarcega@c...> wrote:
> > Seems like an uninteresting topic, but I would like to know whether
> > or not the 18 gauge twisted pair unshielded control cable I have
> > located will work on my Bridgeport NEMA 42 Steppers. There was
> > enough of the old cable to see that it was 16 gauge and not twisted
> > pair. Of course that was running the higher currents and voltages
> of
> > the original BOSS control. I will be using the G201's and a 70VDC
> > 8amp power supply.
> >
> > Thanks?
> > Marty
>
>
>
> --- In CAD_CAM_EDM_DRO@y..., "Marty Escarcega" <escarcega@c...> wrote:
> > Seems like an uninteresting topic, but I would like to know whether
> > or not the 18 gauge twisted pair unshielded control cable I have
> > located will work on my Bridgeport NEMA 42 Steppers. There was
> > enough of the old cable to see that it was 16 gauge and not twisted
> > pair. Of course that was running the higher currents and voltages
> of
> > the original BOSS control. I will be using the G201's and a 70VDC
> > 8amp power supply.
> >
> > Thanks?
> > Marty
>
>
> First i think from reading the forums that bridgeport also used 7 or
> 8 amps for thier steppers.
>
> Second, there are lies, dam lies, and specifications...If you do a
> search for wire current specs on the net you can get any answer you
> want.....But from experance i can give you the following advice...For
> the type of wiring you are doing, multiple conductors in a jacket and
> panel wiring with many wires in a bundle, i would take the
> conservitive aproach and use these ratings. 10Ga-20amp, 12Ga-12amp,
> 14Ga-8amp, 16Ga-5amp, 18Ga-3amp....
>
> For comparison, house wiring would have a different rating because of
> the amount of air space around the conductors and the allowable
> voltage drop. Typical 120vac house wiring For shorter runs of wire
> would be 10Ga-30amp, 12Ga-20amp, 14Ga-15amp.
>
> Personally i would say 18Ga is to small, 16Ga is ok, and 14Ga would
> be conservitive.
>
> As for twisted pair, i would not know how to use it...Twisted pair
> usuaally implies one of the twisted wires is connected to ground,
> possibly that would help noise emmisions. Otherwise 2 power leads
> from stepper could be twisted but i do not know what the outcome of
> this would be....
>
>
> WallyK
>
> P.S. The hardware store usally carries 4 conductor ruberjacketed
> cable....This cable may be of a finer strand then the 18Ga you want
> to use and is probally more flexable....A better choice then typical
> stiff pvc cable....Also the rubber cable can be had in a oil
> resistant rating...
>
>
> Addresses:
> FAQ: http://www.ktmarketing.com/faq.html
> FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
>
> OFF Topic POSTS: General Machining
> If you wish to post on unlimited OT subjects goto:
aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if
you have trouble.
> http://www.metalworking.com/news_servers.html
>
> http://groups.yahoo.com/group/jobshophomeshop I consider this as a
sister site to the CCED group, as many of the same members are there, for OT
subjects, that are not allowed on the CCED list.
>
> NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM.
DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
>
> Post messages: CAD_CAM_EDM_DRO@yahoogroups.com
> Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@...
> Moderator: jmelson@... timg@... [Moderator]
> URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
> bill,
> List Mom
> List Owner
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>