[amsat-bb] Re: elevation rotor

[i8cvs]

----- Original Message -----
From: "Luc Leblanc" <lucleblanc6 at videotron.ca>
To: <amsat-bb at amsat.org>
Sent: Sunday, September 14, 2008 9:18 PM
Subject: [amsat-bb] Re: elevation rotor

> On 14 Sep 2008 at 20:57, i8cvs wrote:
>
> > ----- Original Message -----
> > From: "Gerry" <ve4gtb at mts.net>
> > To: <amsat-bb at amsat.org>
> > Sent: Saturday, September 13, 2008 11:48 PM
> > Subject: [amsat-bb] elevation rotor
> >
 > > > My Kenpro KR-500 elevation rotor has quit working. Has anyone the
> > > voltage outputs on the wiring terminals to the rotor. Like to check
> > > the controller before taking  the rotor down.
> > >
> > > 73
> > >
> > > Gerry VE4GTB / KD7MDB
> > >
> >
> > Hi Gerry, VE4GTB / KD7MDB
> >
> > In a separate message I have sent to you the schematic diagram of the
> > KR-500 so that you will be able to check the controller with easy.
> >
> > 73" de
> >
> > i8CVS Domenico
>
> HI Domenico
>
> It will be his second copy...HI next time i will copy the message to the
> BB!
>
> "-"
> Luc Leblanc VE2DWE
> Skype VE2DWE
> www.qsl.net/ve2dwe
> WAC BASIC CW PHONE SATELLITE
>
Hi Luc, VE2DWE

Since Gerry is requesting to know the voltage outputs on the wiring
terminals to the rotor it follows that in addition to the schematic
diagram it is necessary to add to him the following informations:

With all 6 wires of the control box connected to the rotor the voltage
measured at the rotor between 1 and 3 must be > 6 volt DC
By the way if the rotor is stuck and cannot rotate but the DC voltage
measured between 2 and 3 is ranging betwen 0 and 6 volt depending on
the actual elevation position it is a good indication that probably the
500 ohm potentiometer inside the rotator has not an open circuit in
some place of it.

While running UP the voltage measured between the common of the
motor numbar 6 and numbar 5 must be about 24 Volt AC and if the
voltage measured between 4 and 5 is about 24 volt AC it indicates that
the electrolitic capacitor C3 is not short circuited and both windings
of the motor are OK

While running DOWN the voltage measured between the common of the
motor numbar 6 and numbar 4 must be about 24 Volt AC and if the
voltage measured between 4 and 5 is about 24 volt AC it indicates that
the AC electrolitic capacitor C3 is not short circuited and both windings
of the motor are OK

If the motor don't runs in any of both direction UP and DOWN disconnect
the wires of the control box from terminals 4-5-6 of the motor and measure
the ohmic resistance of the motor windings as follows:
Between terminals 4 and 6 the value of the ohmic resistance must be 5 ohm
Between terminals 5 and 6 the value of the ohmic resistance must be 5 ohm
Between terminals 4 and 5 the value of the ohmic resistance must be 10 ohm

If the motor still don't run check the unpolarized electrolitic capacitor C3
70uF 50VAC located inside the control box and measure it's capacity in uF
because even if the voltage across it as measured between terminals 4 and 5
is 24 volt AC it can be an open capacitor.

If C3 is OK put an AC ammeter in series to terminal 5 and measure
the current flowing into the motor while running UP and do the same
with the ammeter in series to terminal 4 while running DOWN

In both situations UP and DOWN the AC current must be about the same.

The AC motor has a disc brake (27) and a disk pad ( 28) acting as a
friction-clutch but with time the wear of the disc make the friction
of the disc very weak so that the motor runs but the rotator has not the
torque necessary to rotate the antennas.

I hope this helps

73" de

i8CVS Domenico