How do you avoid cracked wires on tunze motorblocks?

[Reefpharmer]

Hello fellow reef aficionados...
This isn’t a thread to bash tunze specifically as I think they make a Fantastic almost bulletproof pump. My only real negative issue w their products (and others w wires inside the tank) is that the wires get hard and over time tend to crack and break near the motor blocks where they are bent to go out of the tank. I really don’t know how to avoid it or fix it. I don’t want open wires inside the tank.
fwiw I have multiple tunze pumps which I am using. My question is how do I avoid the cord issue?

 

[fishguy242]

hi i use 2 part marine epoxy from home depot ,down side is white

 

[Reefpharmer]

To epoxy the broken cable ? Is there a way to avoid it completely?

 

[fishguy242]

or even before broken,the bend,and lights do a number on it ,have considered plastic auto wire loom but never tried ,won't stop the bend at the pump,would work over edge of tank,to stop dry rot from lights

 

[homer1475]

I've used silicone before. Seemed to still do the same thing, but held up much longer.

I don't honestly think there is a way to stop it. It's either dry rot, or just breaking down from UV exposure. Either way I'm not sure, but it happens to anything that gets put into the tank with a wire on it eventually.

 

[Reefpharmer]

Kable Kontrol® Convoluted Black Split Wire Loom Tubing - 1/4" to 3-1/2" Diameter

Order convoluted wire loom by the foot in diameters ranging from 1/4 to 3-1/2 inches. This black split wire loom tubing is resistant to fluids and chemicals.

www.cabletiesandmore.com

Would something like that curtail uv damage?

 

[Water Dog]

Perhaps you can put shrink wrap on the portion of the wire that is submerged in the tank. Have it act as a protective barrier against water and UV damage.

 

[Reefpharmer]

Anyone know whether this type of tubing is safe in the tank? It’s plastic so I’m going to guess perhaps it is but never know...
I’m not sure how to tag people here, maybe Randy know whether this type is safe?
3/8 in. x 10 ft. Flexible Tubing

Gardner Bender 3/8 in. x 10 ft. Flexible Tubing FLX-3810T - The Home Depot

When wires become entangled they are safety hazards, for both the equipment and the owner. Gardner Bender offers a variety of products for protection and neatness. As the needs of professional electricians

www.homedepot.com

 

[kyleinpdx]

Anyone know whether this type of tubing is safe in the tank? It’s plastic so I’m going to guess perhaps it is but never know...

3/8 in. x 10 ft. Flexible Tubing

Gardner Bender 3/8 in. x 10 ft. Flexible Tubing FLX-3810T - The Home Depot

When wires become entangled they are safety hazards, for both the equipment and the owner. Gardner Bender offers a variety of products for protection and neatness. As the needs of professional electricians

www.homedepot.com

More than likely fine, but I'm also very doubtful split loom will do anything. There are three things here you want to minimize:

1. Saltwater: will dehydrate the plastic sheathing and begin to breakdown the polymers comprising that sheathing right from the get-go.
2. UV exposure: will further cause that plastic or rubber/polymer sheathing to become brittle and crack
3. Physical abrasion, tension on the wires, etc: will cause physical strain on the connection points and anywhere else there is uneven pressure (such as at the bend exiting the tank).

You may be better off snipping the male electrical plug at the wall end and feeding the power wire through some airline tubing or other silicone tubing and epoxying it at the pump body and soldering it male end back on. Doing something like this will prevent direct exposure from the tank water, the tubing will lessen the UV exposure to the power cable itself through absorption and refraction and hopefully provide a little rigidity and structural integrity so you're not relying on that bend in the wiring to support the weight of the pump and the wire running to the electrical outlet.

Something like that is the direction I'd take.