Drip Loops and Straws

Many of us are aware that X13 and Fully variable motor failure has peaked over the last few years, and I'm sure there are multiple reasons for that. One of the reasons is fairly simple and can be traced back to two simple installation and service practices that can be easily implemented.

  1. Seal all air handler/furnace/coil penetrations
  2. Use drip loops on wires entering the motor


Eliminating “Straws”

Straws are openings in the cabinet that are unsealed and “suck” moisture into the system. That moisture can cause condensation on the interior surfaces. These “straws” can be copper penetrations, drain port openings, and electrical penetrations.

The presence of straws is a bigger factor on fan coil systems and package units than on furnace/coil systems. That's because, in a fan coil or package unit, warm/moist air can more easily be drawn in after the coil and before the blower.

When unconditioned air enters into the system due to these penetrations, it can cause mold, short circuits, and corrosion. This moisture can also gather on wires and drip into electrical connections, causing issues with motors and control panels.

Make sure to seal any penetrations into the conditioned compartments of equipment with proper rubber grommets or, in some cases, silicone or thumb gum can be used.


Wire Drip Loops 

Anytime a wire enters a plug, board, or motor, it is best to either locate the connection facing down to prevent water from entering or make a drip loop before the connection point. That allows moisture to drip off of the wire before entering the connector or device.

These issues have been identified as causes of X13 and ECM motor failure, and checking these two areas can be very helpful in preventing future failure.

—Bryan

  

Related Tech Tips

Pitch on Line Penetrations
Most techs and installers know that drains need to be pitched. I use the rule of thumb that drain lines should generally be pitched 1/4″ per foot of horizontal run. One thing that can easily be forgotten is pitching wall penetrations when drilling. It's as simple as drilling with a slight upward angle if drilling […]
Read more
Combustion and Confined Spaces
All fuel-burning appliances require oxygen to burn. They require sufficient oxygen to burn clean and safe, without soot and CO (carbon monoxide). I live and work in Florida, where most of our fuel-burning appliances are 80% efficient with open combustion that utilizes air and oxygen from the space for combustion. With these low-efficiency appliances, whether […]
Read more
Boiler Basics Part 3 - Steam
This article was written by Senior Boiler Tech Justin Skinner. Thanks, Justin. Steam plays a very important part in all of our lives, whether we know it or not. Virtually every article of clothing and accessory you are wearing right now relied on steam for either manufacturing or packaging. Hospitals use large steam boilers for […]
Read more

One response to “Drip Loops and Straws”

  1. Thanks for the tip. This is going to save us a lot of problems. I’ve already sharing it! I been pulling my hair, now it makes sense. I’ve mentioned it at work about moisture in air handler. They looked at me crazy, lol. Can’t wait to to rub it in their faces. Thanks, Angel.

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

loading

To continue you need to agree to our terms.

The HVAC School site, podcast and daily tech tips
Made possible by Generous support from