[TowerTalk] US Tower Up/Down Raising Fixture (MD-750) Motor Switch

[Richard (Rick) Karlquist]

As built, the switch on the control box energizes the coil
of a relay that carries the motor current.  That is the
relay that can stick.  Are you saying you are going to
run the motor current (not just the relay coil current)
through your remote switch and bypass the built in relay?
Not following you...

73
Rick N6RK

On 1/1/2019 1:21 PM, Patrick Greenlee wrote:
> I did not propose a relay.  I was thinking of up-sizing the wire 
> sufficiently to obviate a relay.  I concur with your low opinion of the 
> A/C contactors.  I have replaced some of those too. Brute force 
> switching and HD wire run.  Reliable and not prone to failure.
> 
> Patrick        NJ5G
> 
> On 1/1/2019 1:03 PM, Richard (Rick) Karlquist wrote:
>> On 1/1/2019 10:45 AM, Patrick Greenlee wrote:
>>> As you mention, upsize the wire and operate in the dry.  This assumes 
>>> that you aren't at the ragged edge of too much wire loss now. 
>>> Probably not but you could grab a meter and make sure.
>>>
>>> Patrick        NJ5G
>>>
>>
>> The trouble with what you describe is that if the relay
>> sticks on, you are too far away from the tower to
>> kill the power and stop the motor.  The type of relay
>> used is the same as is used in air conditioners, and
>> AC relays are famous for sticking on.  On my HDX-5106,
>> the relay has stuck on twice.
>>
>> 73
>> Rick N6RK
>>
> 
>