Re: RE: (ET) snow blower

["Christopher Meier" <mr23 mn rr com>]

>From a reply sent to me by RJ Kanary,

This reply is going to be based on assumptions, and you know how dangerous
that can be ! I own two snow throwers, [and have never used them, due to a
gravel driveway, and close neighboring yards], plus a spare motor. 
Observing
the arrangement of the terminals on the motor, I would assume that they are
series wound motors. If that be the case, dynamic braking would be a
difficult task to achieve.


RJ Kanary @ Bandi Bros. Inc.
Member TRNi  Since 1998
ASE® Certified Master Auto Technician
Member Tech Line Associates Since 1987
rjkanary nauticom net


----- Original Message -----
From: "Bob Murcek" <RMURCEK geisinger edu>
To: <elec-trak cosmos phy tufts edu>
Sent: Tuesday, October 23, 2001 11:47 AM
Subject: Re: RE: (ET) snow blower


> The PTO relay in the tractor provides the switching for a braking
function, right?  So I'm wondering why it wasn't used on the snowthrower.
Does the thrower have a series motor?  Does dynamic braking work with a
series motor?
>
> >>> Shawn C Passwater <Passwater_Shawn_C cat com> 10/23/2001 12:25:37 PM
>>>
>
> Joseph,
> I use to work for a Automated Guide Vehicle company. The AGVs used a DPDT
> relay and a single pole relay that would parallel a resistor across the 
> PM
> motor for the lift motor and drive motors. The drive resistor was sized 
> to
> stop the vehicle within the distance of the bumper. The dynamic braking
was
> needed in case the drive motor or lift motor brake would fail.  This same
> resistor was used to soft start the lift motor. The DPDT relay would
> energized with the resistor in series with the
> lift motor for .5 -.7 secs. The control would  energize the single pole
> relay jumping out the resistor (resistor and spst was in parallel).
> I can get you  the wattage and resistor sizes that was used for 24 and 48
> volt AGV's.
>
>
>
>
>
> Shawn Passwater
> Caterpillar
>
>