Most of the motors I repaired did not have the limit switches because they were early models. There was one the limit switch was broken and another that had limit switches that I could only attribute to excessive use that overheated and the windings to the point that the enamel broke down (of course, with no certainty). Lightning strikes were much easier to see.
Some of the early Kenpro units did not employ the protective limit switches.
The Kenpro KR-5400 did not have limit switches in either the azimuth or elevation rotors. The Kenpro KR-5600 employed limit switches only on the Azimuth rotor. The Yaesu G-5400 employed limit switches only on the Elevation and employed a thermal switch on the Azimuth rotor. The Yaesu G-5600 employed limit switches on both the Elevation and Azimuth rotor.
The Kenpro KR-5400 and 5400 employed the motor capacitors in the control box. The Yaesu G-5400 moved only the Elevation motor capacitor to the rotor, but left the Azimuth motor capacitor in the control box. The Yaesu G-5600 moved both motor capacitors from the control box to the Elevation and Azimuth rotors.
During Field Day when I had to swap from a Yaesu to Kenpro controller I had to utilize jumpers to add the 100uF capacitor to make the Kenpro Azimuth motor work. Everybody looked at this black plastic capacitor I jumpered on the back of the control box and I just told them it was my Flux Capacitor until some Engineer requested an explanation for its purpose.
73's, Tim - N8DEU
----- Original Message ----- From: "Clive Wallis" list1@g3cwv.co.uk To: "Tim Cunningham" n8deu@att.net; "amsat" amsat-bb@amsat.org Sent: Sunday, October 16, 2011 5:52 AM Subject: Re: G5500 Elevation Rotator Short Circuit?
Thanks Tim.
I'm not aware of any problems with my controller or computer. I notice that there are micro switches to protect against over-run, and wonder why these didn't protect the motor, if one of the circuits had stuck on.
BTW have there been any improvements with the sealing against rain water on this model? It seems better than the previous model, in this respect.
73 Clive G3CWV
On 13/10/2011 21:46, Tim Cunningham wrote:
All of the failures were specifically attributed to either a stuck relay in the control box, a manual switch sticking (not releasing) on the front rotor control panel, and a software or computer crash that continued to drive one of the up, down, left, or right control lines.
73,
Tim - N8DEU
----- Original Message ----- From: "Clive Wallis" To: "amsat" amsat-bb@amsat.org Sent: Sunday, October 09, 2011 11:50 AM Subject: [amsat-bb] Re: G5500 Elevation Rotator Short Circuit?
Many thanks Tim for your comments. From what you've said it sounds like a faulty motor. In the ones you've repaired have you been able to determine the cause of motor over heating?
The problems I've had in the past have always been due to water getting into the units.
73 Clive G3CWV
Hitchin, North Hertfordshire, UK