Beware of Acucraft Wood-Burning Fireplaces

Not many people know that Underwriters Laboratories certifies manufactured fireplaces.  Underwriters Laboratories is a testing organization that tests and certifies many products for use in residential, commercial and industrial applications.  The UL label is a consumer’s indication that a product has been tested and found safe for use by the consumer.  Specifically, manufactured fireplaces have to meet the requirements of UL 127 before certification is approved by Underwriters Laboratories.  In an effort to safeguard life and property, codes organizations, such as the International Mechanical Code, have incorporated the standard.  Municipalities that adopt the International Mechanical Code use the code as a means to determine if a mechanical installation is safe.

A situation was recently brought to our attention involving an Acucraft manufactured wood-burning fireplace.  The fireplace was purchased for $9000.00 for use in a renovated bonus room.  During the renovation, a structural issue arose that required a building inspector to visit the property.  Upon doing so, it was discovered that a permit for the installation of the fireplace had not been issued by the city.  Upon further inspection, the mechanical code inspector discovered that the fireplace did not meet the code requirement for the fireplace to have been certified according to UL 127.  As a result, work on the project was halted.  The useless fireplace is shown below.

 

Acucraft Uncertified Wood-Burning Fireplace

 

Acucraft was later contacted and verified that their wood-burning fireplaces were NOT subjected to any testing protocol such as UL standard 127.  As a result, the homeowners are left with an expensive fireplace that the local codes department will not approve and therefore cannot be used.  Acucraft wood-burning fireplaces can be seen on their website at www.acucraft.com.  It is understood that Acucraft does not sell its products through a retail network but instead, sells directly to the customer.  Before buying a product, be sure that the product meets applicable code requirements in the local area where it will be installed and that the installing contractor obtains the necessary permit for the installation.

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Watch Those Connections!

Some appliances such as stoves and dryers, do not come with line cords when the appliances are purchased.  As a result, consumers have to make separate purchases in order to use their new machines.  When attaching the cords to the appliance, pay close attention to the way the manufacturer requires that the line cords are connected.  For many do-it-your-selfers, this is no big deal.  It shouldn’t be a big deal for a professional electrician either.  However, we are all human and subject to making mistakes.  Case-in-point: the following dryer fire.  Although minor as residential fires go, the damage could have been much worse.  The photographs shown below illustrate how the manufacturer called for the installation of the line cord and the subsequent way, the cord was connected.

The manufacturer’s schematic drawing shows how the “hot” (red and black wires) lines of the line cord were to be attached to the L1 and L2 terminal block terminals.  The common line or white wire was to be connected to the N terminal on the terminal block.  Lastly, the green wire or earth ground, was to be connected directly to the appliance housing.  The photograph below shows how the white and black wires were reversed on the terminal block.

 

 

Since the common and earth ground points are electrically the same point, the dryer was, in effect, energized through the housing.  Anything in contact with the dryer housing, such as the exhaust duct, will also become energized.  Dryer ventilation ducts are usually coils of steel wire wrapped with a thin layer of vinyl or aluminum material.  As current flows through the steel wire, the external covering is heated.  If not stopped, the heat will cause the covering to melt and possibly ignite.

Wheel Separation in 2016 Ford Taurus-Possible Recall?

One of our recent investigations involved the separation of the left front wheel and whether it was the cause of a two vehicle accident.  The scenario was such that the driver made a right hand turn and felt the vehicle pull to the left.  The driver also stated that he lost control and hit a parked car.  Typically, in these types of impacts, the wheel is pushed into the wheel well.  But, in this case the wheel separated from the car.  Upon examination, it was determined that the threaded connection holding the strut to the frame was broken as well as the clamping part of the lower steering knuckle.  The failed parts are shown below.

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Failed strut threaded connection

DSC01042Clamping part of lower steering knuckle found broken

It should be noted that the steering arm tie rod was also bent and broken and that a stabilizing rod connected to the strut was separated from its knuckle joint.  If either of these connections is broken, then the wheel will become unstable.  Are there other instances where drivers have experienced similar situations?  Is this a condition that warrants a recall?

Combined Heat and Power

I just completed a webinar refresher on combined heat and power systems.  If you don’t know or have never heard of a combined heat and power system just picture a jet engine that doesn’t move.  The heat coming out of the exhaust is used to make steam.  On the other end, the rotating fan is connected by shaft to a generator and produces power.  Another type of system uses a boiler to make steam.  The waste heat from the flue gas is reclaimed using a heat exchanger to make additional steam.  The primary steam is then routed to a turbine which in turn, turns a generator and makes electric power.  The secondary steam is sent to whatever process will utilize the steam, such as an absorption chiller, for air conditioning.  Most CHP systems are well suited for industrial applications where large quantities of steam and power are required. However, smaller systems are also made and suited for light commercial applications.  Advertised efficiencies run between 70 and 75% depending on manufacturer.  These machines are fairly reliable and so, in the course of my practice, I have only encountered one instance where a gas turbine (jet engine) failed to perform as required.  Two engines were installed in a university setting and used to provide steam and power to various campus buildings.  Shortly after installation, it was noted that one of the gas turbines was not performing as warranted by the manufacturer.  After review of the design of the entire system, it was determined that one of the gas turbines was not performing according to its design specifications. The claim was finally resolved when the manufacturer agreed to replace the machine with a new gas turbine.

Lathe Chuck Injury Due to Faulty Lathe Operation

One of the more interesting cases that we have been assigned had to do with a personal injury suffered as a result of an airborne chuck.  The injury occurred after an individual purchased a chuck and spindle adapter for use with a Shop Smith lathe that was manufactured back in the late 40s or early 50s (see photos below).

 

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Chuck and pin wrench used to tighten chuck onto spindle adapter

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Antique Shop Smith Lathe

After attaching the spindle and mounting the chuck, the owner started the lathe and tested the operation.  Everything went well until the machine was turned off.  As soon as it was, the spindle shaft stopped but the chuck kept spinning and spun itself off the adapter.  The chuck went airborne, bounced off parts of the lathe and hit the owner’s hand causing severe injury.  The investigation came about as a result of the owner’s allegation of a defective product, ie, the chuck was defectively designed and had no means of stopping if it separated from the spindle adapter.  The chuck is designed to be tightened against the spindle adapter using special wrenches.  According to the owner, he claimed that he “tightened the chuck as tight as he could” before starting the lathe.  During the examination of the lathe, the lathe was started and run without the chuck attached.  When the lathe was turned off, it immediately became clear that there was something wrong when the spindle shaft did NOT coast to a stop.  It was also clear that the abrupt stop provided the torque necessary to cause the chuck to spin off the spindle adapter.  In addition, it was also noted that if the chuck was to stay attached to the spindle adapter, the torque applied during tightening had to be greater than the torque causing separation.  After working the math, it was determined that the owner could not have tightened the chuck was much as he claimed.  As a result, it was further determined that the owner unfortunately caused his own injury by ignoring the problem of abrupt stopping of the spindle shaft.  The lawsuit was subsequently dismissed.

Power Steering Recall

Roughly two years ago, Chrysler recalled approximately 442 Dodge Ram pick up trucks for a problem with the electric power steering (EPS) module.  The recall applied specifically to 2015 -2016 Ram 1500 trucks manufactured between January 22, 2015 and September 13, 2015.  The problem had to do with short circuiting of the EPS circuit board that would cause the loss of power steering and increase the risk of a crash.  Since that recall was put in effect, reports have been received that indicate that the short circuit is not enough to cause the 100 amp fuse, that is supposed to protect the module, to open.  As a result, the short circuits are causing wiring to overheat and ignite resulting in vehicular fires.  It should be noted that overheating of the wiring has not been addressed and is not part of the original recall.  The original recall is identified as NHTSA campaign # 16V16700 and Chrysler recall # S19.  A copy of the recall is attached below.  The second page shows a wiring diagram and the connection between the EPS module and battery through the 100 amp fuse that is in question.  Also shown is the connection between the battery and the power center.  If a fire occurs, the origin appears to be in the area of the battery and power center, both of which are located on the driver’s side of the engine compartment above the left front wheel well.  Complaints regarding vehicular fires related to this recall should be reported to NHTSA through their website at www.nhtsa.gov.

Recall & wiring diagram0001

Recall & wiring diagram0002

Long Hydraulic Hoses Cause Trencher Fire

Heavy equipment used on construction sites are subject to all kinds of conditions.  Those conditions include, bad weather, rocky terrain, and remote locations.  All of these factors can play a part in determining whether a vehicle will ignite and burn.  We were recently asked to examine a trenching machine that was destroyed by fire.  The machine that was examined is shown below.

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One of the most common causes of heavy equipment fires is hydraulic fluid leaks.  It is well known that hydraulic fluid is flammable and will ignite with the correct mixture of air and an ignition source.  Such sources can include engines and transmissions as well as electrical devices.  Although these are some of the more common factors, sometimes unusual circumstances can also lead to a piece of equipment being destroyed.  In the case of the fire damaged trencher, one of the findings included hydraulic hoses being long enough to reach the ground.  As a result, while the trencher was in operation, dirt was actually burying the hoses.  At the same time, the movement of the machine, as the trench was dug, was pulling the hoses through the dirt and causing the hoses to tear.  Hydraulic fluid leakage was not only inevitable but, so was the possibility of fire.  When hydraulic hoses have to be replaced, the lengths of the hoses are a maintenance issue.  It is extremely important that hoses of correct length are installed,  If the hose is short and fits tight between connections, the stress imposed by forcing the hose to stretch coupled with the stress of pressurization, can cause premature failure.  Likewise, a hose that is longer than necessary will move around and possibly make contact with solid objects that can wear or cut the hose jacket, weakening the wall.  As in this case, the dirt and rocks contributed to the weakening of the hoses found beneath the conveyor section, on the ground, and the subsequent release of hydraulic fluid that ultimately ignited and destroyed the trencher.  The hoses that were found are also shown below.

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