Towertalk
[Top] [All Lists]

[Towertalk] Secrets of UST Controls

To: <towertalk@contesting.com>
Subject: [Towertalk] Secrets of UST Controls
From: tavan@tibco.com (Rick Tavan)
Date: Thu, 31 Oct 2002 10:56:47 -0800
If you have a US Tower crankup that sometimes refuses to move, you may 
enjoy the following trouble-shooting tips. YMMV since some control boxes 
may be different from mine, but this is what I learned from their 
electrical expert:

Inside the control box on the tower, there are up/down relays on either 
side of the main power relay. These are above the white time delay 
relays. On the outside of each relay is a little plastic button. Depress 
that button to energize the motor directly, bypassing both the time 
delay relay and the limit switch. If you have a problem with the time 
delay relay or limit switch, this will work. If you have a problem with 
the up/down relay or the motor, this won't help.

If you have a remote control, you can take it out of the circuit as 
follows: Disconnect all seven wires from the remote control. Connect a 
spare AC pigtail with hot (black or red) to C3, neutral (white) to C4 
and ground (green) to ground. (I don't see why you couldn't do this with 
jumpers off the main power terminals, but the electrician described a 
separate pigtail.) Connect a jumper from C3 to C6. If you have a problem 
with the remote control box or its cable out to the tower, this should 
work. If the problem is at the tower, this won't help.

Safety precautions: Disconnect all power while making these connections. 
Simulate time delays when using the up/down bypass pushbuttons to avoid 
reversing the motor too quickly. Be careful not to touch the terminals 
of the up/down relays when reaching around to push a bypass button. 
Observe all the usual precautions for working with towers and power 
circuits.

No, I have not solved my intermittent tower-won't-move problem. When the 
electrician called, it was working all by itself after 24 hours of 
futile efforts. But the next time it fails, these hints should help me 
figure it out.

73,

Rick N6XI




<Prev in Thread] Current Thread [Next in Thread>