Source for SO cord with air tube

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Barbqranch

Barbqranch

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Arcata, CA
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Plant maintenance electrician Semi-retired
I have seen on some sump pumps an SO cord that also has a small diameter air tube inside that is used as a reference pressure for a water level switch.
I have a project that would benefit from such a cord, but I have no idea where to purchase it if it is even available. Anyone know of a source?
 
It may only be available as a component to manufacturers in large quantity. (only UL listed as a registered component?)
If you need a short distance, a replacement part cord set may be the best you can do.
 
I’m thinking you saw something that someone made themselves by putting an air tube next to a submersible pump cable and slipping some heat shrink tube over it all. If it were integrated into the jacket of the cable, the air tube would need to be broken out of the cable jacket before the wires went into the pump sealing fitting. I can’t see how that would allow for a good reliable seal. If it were separate heat shrink tube though, you just end that tube wherever you need the air line to break out and continue the normal submersible cable into the standard gland fitting.

I’ve done similar, but I didn’t waste the heat shrink by going the entire length. That’s overkill. I just put 3” sections about every 2 feet to keep the tubing with the cable going down. It holds up better than tape and there is no risk of over tightening a cable tie and pinching the air line.
 
It was integral with the cable, and the plug even had an air vent hole for it. GoldDigger is most likely correct, but I was hopeful someone might have a source.
 
Jraef said:
I’m thinking you saw something that someone made themselves by putting an air tube next to a submersible pump cable and slipping some heat shrink tube over it all. If it were integrated into the jacket of the cable, the air tube would need to be broken out of the cable jacket before the wires went into the pump sealing fitting. I can’t see how that would allow for a good reliable seal. If it were separate heat shrink tube though, you just end that tube wherever you need the air line to break out and continue the normal submersible cable into the standard gland fitting.

I’ve done similar, but I didn’t waste the heat shrink by going the entire length. That’s overkill. I just put 3” sections about every 2 feet to keep the tubing with the cable going down. It holds up better than tape and there is no risk of over tightening a cable tie and pinching the air line.
Click to expand...
The whole idea of the cord described is to vent the sealed motor interior and other spaces on the opposite side of the sealing gland. This seal is to keep water out, not prevent explosive gas migration. The vent keeps the motor interior approximately at ambient pressure to reduce the chance of seal blowouts from air expansion.

Edit: Tom's explanation below seems much more likely.
 
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A sump pump I had used a diaphragm switch, the internal air line provided the atmospheric reference. This I discovered when I replaced the male plug on the cord , had to modify the cord end so the vent was exposed
 
Cable with integrated air tubes are common on submersible pressure (tank level) sensors. The air vent is necessary to accommodate changes in atmospheric pressure that mess with the zero. The sensors need to accommodate pressure changes or it may look like the tank is either more or less full than reality. Large pressure swings can actually damage the sensors if the compensation tube is blocked.

It's apparently referred to as "vented cable."

Vented Cable, Vent Tube Cable | Galaxy

Vented/Vent Tube Cables - Galaxy is a leading supplier of custom and stock vented cables, also known as vent tube cables.
www.galaxywire.com www.galaxywire.com


SceneryDriver
 
LarryFine said:
Eustachian tubes for equipment. 🤧
Click to expand...
That is just what I need.

SceneryDriver said:
It's apparently referred to as "vented cable."

Vented Cable, Vent Tube Cable | Galaxy

Vented/Vent Tube Cables - Galaxy is a leading supplier of custom and stock vented cables, also known as vent tube cables.
www.galaxywire.com www.galaxywire.com


SceneryDriver
Click to expand...

Thanks SceneryDriver, that name is exactly what I needed. I only work Thursday and Friday, so I will try to call them then. I really appreciate the info. That is what makes this list such an asset and resource.
 
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