Catalina 34

General Activities => Main Message Board => Topic started by: rmbrown on April 16, 2017, 07:19:02 PM

Title: Masthead Wiring Stress Relief
Post by: rmbrown on April 16, 2017, 07:19:02 PM
I'm rewiring my mast this weekend... for the second or third time for but this time for real!

I can't find anything telling me how to relieve the stress on all that hanging wire.  Any recommendations of what I can do at the top so the electrical connections and mechanical fasteners at the mast head aren't taking the full load of all that hanging wire?
Title: Re: Masthead Wiring Stress Relief
Post by: KWKloeber on April 16, 2017, 09:40:52 PM
 Mike,

Wiring, whether in a mast or anywhere else must have ZERO strain on connections (terminals, connectors, terminal strips, busbars, etc.).   I can't speak to your particular situation, where the wires exit etc. but you need to use possibly a combination of methods and strain reliefs.  Plastic squeeze-together strain reliefs where wires exit a hole in the mast; forming a zip tied loop to use to "hang" a wire bundle; nylon or rubber-lined cable clamps, etc.

kk
Title: Re: Masthead Wiring Stress Relief
Post by: Craig Illman on April 17, 2017, 05:52:59 AM
I think I remember an overhand knot of the wires around the bolt that connects the port and starboard upper shroud fittings. Sorry, I don't have a picture.

Craig
Title: Re: Masthead Wiring Stress Relief
Post by: Ron Hill on April 17, 2017, 02:37:21 PM
Guys : The Catalina factory used an overhand knot around the bolt that holds the mast head into the mast spar!!
I did the same when I redid the mast head wiring fixtures and adding a TV antenna.  Wrote a Mainsheet tech note article on pulling the mast and that rewiring.

A thought
Title: Re: Masthead Wiring Stress Relief
Post by: Dave Spencer on April 17, 2017, 04:14:38 PM
Thanks Ron,
I'll look up your tech note article as I'm looking at modifying some of the equipment and therefore the cables at my masthead. 
I can't imagine how Catalina would have tied a knot around the bolt holding the masthead on because the masthead must be off to get access to that area so the bolt wouldn't be in place. 
Currently on my mast, the wind instrument cable is secured with a clamp on the top of the masthead casting.  My anchor light is poorly secured with a knot in the cable at the base of the fixture.  The VHF coaxial cable enters my mast from the side about a foot below the masthead and looks to be poorly secured by only a friction fit bezel.  Definitely room for improvement.
Title: Re: Masthead Wiring Stress Relief
Post by: KWKloeber on April 17, 2017, 05:05:34 PM
Remember that it was OEM wired with no weight on the wiring, so things can be "finagled."

I used these where I have cables thru the mast:

(https://www.heyco.com/Strain_Relief_Bushings/img/4-22_114.jpg)

They don't need to be tight (pinching the cables,) tied a knot or used a zip tie outside it. 

I covered exposed wires so that UV is working on something sacrificial (HST, silicone tape, etc,) rather than on the wiring/insulation itself.

kk
Title: Re: Masthead Wiring Stress Relief
Post by: Dave Spencer on April 17, 2017, 06:03:33 PM
Thanks Ken,
That looks like the "friction fit bezel" that I referred to in my previous post. 

Title: Re: Masthead Wiring Stress Relief
Post by: Noah on April 17, 2017, 06:48:25 PM
I used wiring glands at ever penetration.