Cut Those Tree Limbs!!!

I just completed an assignment where contact between a power line and a tree limb caused damage to several home appliances. We all know that power lines are sometimes routed through tree branches between the transformer and the weatherhead on a residential or commercial building roof.  It’s also no secret that electricity can travel through a tree.  In this particular case, contact with the limb came about as a result of rubbing so that when the wire insulation had worn off and the conductor was exposed, a short circuit to ground was created.  When this happens, current is going to go in all directions.  It is possible to energize the neutral side of a building’s electrical system so that current is fed into an appliance in the wrong way which causes damage.  Although electric utilities sometimes take on the responsibility for pruning tress, home and building owners should be proactive in helping to maintain the safety and reliability of power distribution.  As this article is being written, the northeast is being “slammed” with a huge winter snow storm.  It’s no stretch of the imagination to conceive of the number of power lines that will come down as result of broken tree limbs.  But, keeping tree limbs pruned and off power lines can mean the difference between staying warm and waiting several hours if not days for utility crews to make repairs.  Remember, unless you are in an extremely isolated area, the transformer that feeds you home or business, also feeds your neighbor’s homes and businesses.

What’s Going on With Carrier and Goodman?

 

For a number of years, the Carrier Corporation has been manufacturing air conditioning equipment and selling their products all over the world.  Virtually everyone in the HVAC industry and a large part of the consuming public is familiar with the Carrier name.  To a lesser extent, the Goodman Company has also been manufacturing air conditioning equipment.  Although the Goodman Company is not was well known as Carrier, the two companies manufacture some of the same products.  Case in point: packaged terminal air conditioning units or PTACs as they are more commonly known.  These are units that are commonly found in motel rooms.  Recently, both companies recalled some of their PTAC units, Carrier on December 22, 2015 and Goodman on February 17, 2016.  But, the most troubling commonality is that the recalls are for the same problem.  That is, both companies recalled their products because their PTACS were equipped with line cords that could overheat and pose a burn hazard to consumers.  The only reason that line cords overheat is because they are sized too small for the unit’s load; i.e. the unit is drawing more current than the line cord can handle.  How does that happen?  This problem is not something that has been recently discovered.  It is not something that belongs to new technology innovations.  Any company that has been manufacturing an electrical device for any length of time has to know full well what the consequences are of undersized wiring for a specific load.  So, again how do companies like Carrier and Goodman get it wrong?  If the problem can’t be in the lack of knowledge, it has to be in the manufacturing process.  Maybe it’s time for some worker retraining.