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@consolidated.net>
>Sent: May 27, 2008 5:05 PM
>To: towertalk@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
>
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