----- Original Message -----
From: "Joe" <w5asp@earthlink.net>
To: <towertalk@contesting.com>
Sent: Thursday, August 08, 2002 3:22 PM
Subject: Motor Start Capacitors
> While this is nothing new to many of you, there are a number of real
> advantages in putting the motor start capacator on the tower at the
rotator.
>
> First of all, that's where it ought to be. Check most any industrial
> electric motor installation and you will find the motor start capacitor on
> or near the motor itself. Putting it several hundred feet away is hard to
> justifiy in so far as good engineering practice goes.
>
> Second, many users think that the "black and white" wires (Terminals 1 &
2)
> are the primary motor current carrying wires ... otherwise why would they
> be of a heavier gage. Wrong ... these two wires simply provide currrent
to
> the brake solenoid. The current to the motor windings uses only one of
> these wires along with two of the other smaller gage wires. By freeing up
> two of the wires in the normal 8-conduction rotor cable by putting the
motor
> start capacitor on the tower, it allows the two extra wires to be
paralleled
> with the "return" leads from the two motor windings, which reduces power
> loss and assists the motor in turning more reliably.
>
> Finally, capacitors designed for use with industrial motors are very
rugged.
> The ones that come from a source like Gainger are expected to live in the
> cruel, harsh external world. (Go look at you outside A/C unit's fan motor
> cap.) If properly installed, they will outlast most amateur antennas.
We've
> had them on towers for over 15 years with no failures.
>
> We took care to use quality stranded electrical wire and to ":pot" the
> connections with electrical quality RTV. They are mounted with the
> connections down and placed just beneath the rotor plate. It's worked for
> us.
>
> Joe, W5ASP
>
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