[GreenKeys] LMU 11 motor

[Duncan Brown]

I am wondering if it is a shorted starting capacitor or a short in one 
of the windings. Besides the thermal overload opening fairilly quickly, 
I could hear a "snap" in the power switch when I turned it on, so 
something is drawing a lot more current than it should.

  I did not get a chance to pull the motor while I was at the Museum 
today, so it will have to wait until next week.

I realize that I will not be able to find an exact replacement starting 
cap.  I've replaced the starting cap on a M28 KSR and ended up 
ty-rapping the cap to the LSU and running long leads into the motor box.

  Thanks,

Duncan
K2OEQ

On 02-Aug-22 16:07, John, W9DDD wrote:
>
> My swag would be open main winding, but would the start winding pull 
> enough current to trip the overload?  Perhaps?  Never thought about 
> the start winding having any function other than getting things going 
> in the right direction.  Perhaps it is the source of a lot of the 
> inrush current during starting.  Motors course was my least favorite 
> course ... well maybe thermodynamics makes it the second least favorite?
>
> Now that I think about it, if the main winding was open, then the 
> start relay wouldn't engage the start winding.  How about one of the 
> two windings being shorted?
>
> Bad start relay acts the same as bad cap in my past experience.
>
> What would happen if the cap was shorted?  No phase shift performed, 
> doesn't know which way to turn.  Would think the push would still get 
> it going?
>
>
> ---
> ----
> You said "tomorrow" yesterday.
>
> The above comments or recommendations are SWAG. Use at your own risk.
> John, W9DDD
> On 8/2/2022 12:37 PM, Duncanancy wrote:
>>
>>
>> Turned on my 28 RT today and the motor hummed for a minute and then 
>> tripped the thermal overload.
>> I can turn the motor by hand and it seems normal resistance. When 
>> powered, it just seems to wiggle back and forth. Giving a push in the 
>> proper direction does nothing.
>>
>> (On another M28 , the motor would not run until you gave it a push - 
>> then it would run. Replacing the motor start cap fixed it.)
>>
>> But on this 28RT, giving a push doesn't make it run.
>>
>> Does this sound like the motor start cap?  Any good sources for M-S cap?
>>
>> Thanks,
>>
>> Duncan
>> K2OEQ
>>
>>
>> Sent from my Kleinschmidt TT-4/TG, the US Army's first portable 
>> digital communications device, 1950-1980
>>
>>
>>
>>
>>
>> ______________________________________________________________
>> GreenKeys mailing list
>> Home:http://mailman.qth.net/mailman/listinfo/greenkeys
>> Help:http://mailman.qth.net/mmfaq.htm
>> Post:mailto:GreenKeys at mailman.qth.net
>>
>>>>> Jordan Spencer Cunningham's GreenKeys Search Tool:https://teletype.net/gksearch
>>>>> 2002-to-present greenkeys archive:http://mailman.qth.net/pipermail/greenkeys/
>>>>> 1998-to-2001 greenkeys archive:http://mailman.qth.net/archive/greenkeys/greenkeys.html
>>>>> Randy Guttery's 2001-to-2009 GreenKeys Search Tool:http://comcents.com/tty/greenkeyssearch.html
>> This list hosted by:http://www.qsl.net
>> Please help support this email list:http://www.qsl.net/donate.html
>> Message delivered tow9ddd at tapr.org
>
>
> ______________________________________________________________
> GreenKeys mailing list
> Home: http://mailman.qth.net/mailman/listinfo/greenkeys
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:GreenKeys at mailman.qth.net
>
>>>> Jordan Spencer Cunningham's GreenKeys Search Tool: https://teletype.net/gksearch
>>>> 2002-to-present greenkeys archive: http://mailman.qth.net/pipermail/greenkeys/
>>>> 1998-to-2001 greenkeys archive: http://mailman.qth.net/archive/greenkeys/greenkeys.html
>>>> Randy Guttery's 2001-to-2009 GreenKeys Search Tool: http://comcents.com/tty/greenkeyssearch.html
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to duncanancy at earthlink.net