[TowerTalk] Tower Control

[NPAlex at aol.com]

Dan,
Limit switches for tower control are usually pretty straight forward  circuit 
interrupt devices.  There is the rest of the control circuitry  however that 
needs to be considered. Your winch was stated as being a  Dayton AC model.  
The next question is point of control, is it just a  forward reverse switch at 
the tower, or do you plan on controlling it  remotely?  
 
In the remote case some form of limit switch is essential, but usually  
easily accomplished because you already would have UP and DOWN control relays  
located at the tower.  In this case the UP limit switch interrupts the UP  relay 
coil, and the DOWN relay coil upon lowering the tower.  These  relays would be 
low voltage types (24vac or less) which then requires the  cabling and limit 
switches to operate at low voltage.  Running 115 vac  through a limit switch, 
and the connecting cable may not meet code in many  areas.  So low voltage 
UP/DWN motor control relays may be mandatory.  
 
If local control, you should have visual control and with the possible  
addition of a couple of paint marks to indicate the max up or down positions  that 
may be all you need.  I would only use a spring loaded center off  control 
switch which requires "hands on" to maintain power.  However even  in LOCAL 
control conditions I would recommend using motor direction control  relays as in 
the remote case.  One additional safety item required in such  a system is a 
time delay circuit for each motor control relay.  5 sec delay  is usually 
adequate, and the reason the time delay is to allow the motor to come  to rest before 
applying the reverse voltage.  If you do not delay the  activation of the 
relays, and the relay activates while the motor is still  rotating, it will 
continue to run in that same direction, why? because the start  or reversing 
winding is switched out while rotating, so it does not know you  wanted to change 
direction of rotation.
 
So plan on a couple of 24v DPDT relays, maybe a Power ON relay, two 5 sec  
amperite delay switches, 24vac transformer and a wx proof box at the tower  to 
house it all in.
 
Regards,
Norm W4QN
==================================

>From: Dan <dandiy at consolidated.net>
>Sent: May 27, 2008  5:05 PM
>To: towertalk at contesting.com
>Subject: [TowerTalk]  Connecting limit switches on a tower winch
>
>I came across this  reflector after doing a search on tower winches.
>
>I mounted a  Dayton AC winch with forward reverse to my Hy Gain HG55SS Crank
>up tower.  It works like a charm, but I want to mount two limit switches  on
>it.
>
>I have two Allen Bradley 802T switches, the same  used on some commercial
>solutions. 
>
>Since I cannot  afford a $2000 solution from the commercial tower companies,
>I hope  someone on this reflector has done what I want to do, or can provide
>me  with a wiring diagram on how to go about this.
>
>Any help would be  greatly appreciated.
>
> 
>
>Dan 
>
 



**************Get trade secrets for amazing burgers. Watch "Cooking with 
Tyler Florence" on AOL Food.      
(http://food.aol.com/tyler-florence?video=4&?NCID=aolfod00030000000002)