The case of the exploding blender:  We were enjoying a dinner with our friends, Geraldo and Maria, over at their condo here in Guanacaste, Costa Rica recently.   After dinner was over we were sitting at the dining room table enjoying a glass of wine and some dessert.  Suddenly there was a noise like a bang or a pop that came from the area of the kitchen.  It made us all jump, as it was quite loud!

I had the best view of the kitchen from where I was sitting, and seeing nothing obvious, I remarked that someone must have hit something against the wall in the adjoining condo unit.  Geraldo, with his back to the kitchen, thought it was another round of celebratory fireworks starting up.  Then I noticed the white smoke coming from the kitchen countertop.  “Houston, we have a problem in the kitchen”.  We jumped up to investigate and witnessed some acrid smelling white smoke accompanied by some sizzling and popping coming from an innocent countertop blender.

Geraldo whisked the blender outside to cool off and finish smoldering outdoors, and then we started the post mortem.  Maria asked me the question: “Why would that happen”?  I responded in the most authoritative and educated way I knew how with, “I don’t know”?

I guessed that a capacitor must have taken a voltage spike and, in electronic terms, hit the break-over threshold and exploded.  None of us noticed anything unusual with the lights in the room prior to the blender’s little outburst, but spikes can happen in an instant, and aren’t always noticeable.

Maria then asked: “Why would it happen when it isn’t being used, or even turned on”?

When anything electronic is plugged in they still have power right up to the control board, which are all solid state electronics these days.  Not many appliances have a standard on-off switch that acts as a disconnect when not in use.

Anyhow, that got me curious, and I asked permission to dismantle the unit to see exactly what parts exploded inside.  As near as I could tell, it was a capacitor, and it literally blew itself clear of the printed circuit (PC) board when it exploded, and was melted to the bottom of the blender housing.  The PC board had a lot of collateral damage adjacent to the area the capacitor once called home.

Here’s a look at the blown capacitor.

The Damaged PC board

Both in perspective

Could this have caused a fire?  Depending on the countertop material, or the flammability of the surrounding area, I would say not too likely, but certainly possible.  In this situation the countertops were granite, the backsplash porcelain tile, and the capacitor ran out of smoke after blowing itself clear of the PC board so it’s not too likely that the unit would have burst into flames.

Again, Maria asked the question: “Should we be unplugging countertop appliances when we aren’t using them”?

Sandy has done some searching on this topic, and found the following recommendations:

According to the U.S. Consumer Product Safety Commission , “Unattended, plugged-in appliances may create an unnecessary risk of fire”.  Their recommendation is to unplug all of your countertop appliances when not in use.

They also have an excellent room-by-room home electrical safety check list that is worth taking a look at.

The most common danger with small countertop appliances can occur when the appliance cord is damaged, frayed and/or wires are exposed.  Make sure that your countertop appliances are not too close to a heat source, as this can damage the cord as well.  If one of your small appliances has a cord that is damaged, don’t attempt to repair it yourself.  Have the cord replaced.

Another potential risk with appliances in general is a product recall.  There are a number of websites that provide updates on the different types and manufacturers of appliances large and small.  Here are a few sites that you can check:

http://www.saferproducts.gov/Default.aspx

http://housewares.about.com/od/productrecalls/

After doing a little digging, it appears that there are greater fire risks associated with large appliances, like a dishwasher, range or fridge.  The reasons for this appear to be the increasing complexity of appliance design and electronics, and concerns with the growing number of appliances or appliance parts that are being manufactured abroad where control systems may not be as rigid as in the U.S.

Bottom line for myself, having witnessed what we did that night, I think I’ll make a point of trying to remember to unplug all of my small countertop appliances if I’m leaving the house unattended for a period of time.

How about you?  Have you ever experienced a similar problem with an appliance?