What a Way to Blow up a Blower!

Most residential and commercial HVAC equipment use centrifugal blowers to move air through duct systems.  The rate at which blower wheels turn is usually between 1000 and 1500 rev/min, depending on the application.  The point to be made is that blower wheels turn at a fairly slow speed.  Blower wheels that are attached directly to the motors that drive them turn at the rotational speed of the motor.  But, when the blower wheel is belt driven, the speed of the blower can vary depending on the size of the pulley attached to the shaft that drives the blower wheel.  If the size of the pulley attached to the blower shaft is twice as large as the pulley attached to the motor, the speed of the blower will be half of the speed of the motor.  If however, the blower pulley is the same size as the motor pulley, the blower will turn at approximately the same speed as the motor.  If the blower wheel is not designed for such speed, the centrifugal forces created by the rotational motion will cause the blower wheel to fail in a spectacular way.  The photos attached below illustrate the results.   

Blower louvers peeled away from blower ring
Blower louvers peeled away from blower ring
View of damage to blower louvers

Jeep Wrangler and Gladiator Vehicles Recalled

Fiat Chrysler Automobiles has announced that it has recalled 2018 – 2020 Jeep Wrangler and 2020 Jeep Gladiator vehicles equipped with manual transmissions.  These vehicles contain a clutch plate within the transmission that can overheat and fracture, posing a fire hazard.  If the fractured pieces crack the transmission casing and come in contact with combustible material, a fire can result.  Approximately 33,237 vehicles are involved in this recall.  Owners should be aware of signs indicating a problem: the sudden loss of power, burned clutch smell, and extra pedal travel when shifting gears.  At present, Fiat Chrysler is working on a repair but expects to begin recalling vehicles on April 22nd of this year.  Owners of affected vehicles will receive notices of the recall by mail.  For additional information, owners can contact Chrysler customer service by calling 1-800-853-1403 and referencing Chrysler recall # W12. 

Hyundai Recalls Elantra and Elantra Touring Vehicles

Hyundai Motor America has announced that it is recalling 429, 686 Elantra vehicles for a problem with the ABS (antilock braking system) module that can cause an engine fire.  The vehicles involved in this recall are: 2006 through 2011 Hyundai Elantra manufactured between August 26, 2005 and November 23, 2010; and 2007 through 2011 Hyundai Elantra Touring vehicles manufactured between June 21, 2007 and December 6, 2010.  It should be noted that the recalled vehicles are no longer in production.  The problem with the ABS module is that moisture can enter the module and cause the circuit board to short circuit.  The short circuit CAN occur even if the vehicle is turned off.  Hyundai Motor America plans to notify owners and request that they return their vehicles to their dealers for repair.  The repair will consist of the installation of a relay in the main junction box.  The intent is to deenergize the ABS module when the vehicle is turned off.  This repair will be performed at no cost to the vehicle owner – Hyundai plans to reimburse owners for out-of-pocket expenses.  It is recommended that owners communicate with their dealers and make sure they understand what allowable charges are and what will be reimbursed.  Notification of owners and dealers will begin in April 2020.  For additional information, owners can contact Hyundai by calling 800-633-5151 and referencing manufacturer recall number 188. 

Toyota Recalls Vehicles for Faulty Fuel Pumps

Several news outlets including ABC News and CBS News are reporting that Toyota is recalling nearly 700,000 vehicles for a faulty fuel pump.  The fuel pumps can stop pumping fuel without warning and cause the vehicle’s engine to stop.  A sudden loss of engine power can result in loss of control and increases the risk of a crash.  The following vehicles are affected:  2018 and 2019 Lexus LS 500, LC 500, RC 350, RC 300, GS 350, IS 300, ES 350, LX 570, GX 460, and RX 350 models; and 2019 Lexus NX 300, RX 350L, and GS 300.  In addition, 2018 and 2019 Toyota 4Runner, Camry, Highlander, Land Cruiser, Sequoia, Sienna, Tacoma, and Tundra vehicles are recalled.  Furthermore, 2019 Avalon and Corolla are also included in this recall.  Other than the Lexus models, only certain models of the other vehicles are affected.  For additional information, owners should go to Toyota’s website, www.toyota.com,  and enter their vehicle identification numbers in the recall page to see if their vehicles are part of the recall.  Support is also available by calling 1-800-331-4331.

Space Heater Fire Cause

Recently, we were asked to investigate a fire involving a newly purchased space heater. Space heaters tend to be small heating appliances meant to heat “small” spaces inside a home or other building. In this particular case, the heater was intended for use with propane gas and rated with a capacity of 30,000 BTU/hr. The homeowner had purchased the heater from a local Home Depot store and installed the heater himself. The installation amounted to connecting the heater to a gas supply line. After approximately three days use, a fire occurred. Luckily, the fire was quickly extinguished with minimal burn damage to the floor and smoke damage throughout the remainder of the home. Upon visual examination of the gas line connection, it was noted that the shutoff valve had been attached to the heater gas line fitting. The proper position for the shut off valve was in the gas supply line from the home at the point where the line was accessed above the floor. The outlet of the valve is then supposed to be connected to that part of the gas line that is connected to the heater. However, the main problem was found to have been in the connection of the valve to the heater fitting. The shut off valve appeared to have been cross-threaded onto the fitting. The pipe joint compound used to seal the threaded connection was also scorched and was indicative as well as a confirmation of a gas leak at that point. In should be noted that since propane is heavier than air, an accumulation around the heater while it was in operation would have ignited, which is what actually happened. The photographs below show how the shut off valve was misaligned with the heater fitting and the resulting damage to the heater.

Holiday Fires

This is the time of year when everyone gets excited because Christmas is almost here.  It’s also the time when happiness can turn to disappointment in the blink of an eye.  Disasters caused by fire don’t take a holiday just because it’s Christmas.  This is a time when we need to be especially careful when hanging lights and decorating our trees.  If your strings of lights are frayed, bare or arcing, don’t use them.  If you are using ornaments that contain internal lighting, be sure that the wires are not pinched, the insulation is not cracked and that the bulbs are securely in place.  In addition, be sure that the plugs are in good condition and the prongs are not loose or broken.  Be careful using extension cords.  If you are hanging exterior lighting and you need an extension, be sure to use an extension approved for exterior use.  Do not use an interior extension cord with exterior lighting as they are typically not weather proof.  Rainwater entering the connection can easily cause a short circuit.  Keep an eye on timers and automatic switches to make sure that they turn on and off at the appropriate times.  Just some food for thought…

Wishing everyone a safe and happy holiday season.

Brake and Battery Issues Prompt GM to Recall Trucks

General Motors has recalled approximately 464,000 Cadillac CT6, Chevrolet Silverado 1500 and GMC Sierra 1500 trucks, all 2019 model year vehicles.  GM has discovered that a software error can disable the electronic stability and antilock braking systems.  According to the National Highway Traffic Safety Administration (NHTSA), dealers are supposed start repairing recalled vehicles on January 27, 2020.  The repair will consist of reprogramming the antilock brake computer.  GM has also recalled 350,000 model years 2019 and 2020 Chevrolet Silverado 1500 and GMC Sierra 1500 pickup trucks.  The problem with these vehicles is that the cable that goes from the battery to the alternator has too much glue in it.  As a result, the glue imposes a resistance to the flow of current and can cause the engine to stall, and possibly ignite.  This recall is also expected to begin on January 27, 2020.  Dealers are supposed to inspect the cables and clean the connections if necessary.  For additional information, owners can contact GM by visiting their website at www.gm.com, then scrolling to the bottom of the page and click on recalls.   Please have your vehicle identification number ready as you will be prompted to enter it to see if your vehicle is affected. 

%d bloggers like this: