Basic Circuit Troubleshooting

When your dryer, vacuum cleaner, blender, or any other appliance suddenly won’t work, most people do one of two things. Either they throw it away and pay for a new one or they pay almost as much having someone spend fifteen minutes to an hour to fix it for them.

There is a third option that has been forgotten by many. Fix it yourself. After all, most people didn’t learn about circuits in school, although maybe we should have. It’s extremely valuable information.

An appliance can look a little intimidating sitting there looking pretty in your kitchen or laundry room, but actually most are fairly simple machines made up of a collection of mechanical devices and circuits. The home appliances that we use every day are not magic boxes. They operate by basic rules. Understand those rules and, suddenly, what was a huge expense becomes an interesting puzzle. Understanding how a circuit works will give you the confidence needed to save more of your hard earned money and feel the satisfaction that comes with taking care of business.

An electric circuit is a path, or several interconnected paths, capable of carrying an electric current. Most circuits have four basic parts:

  • a power source,
  • conductors,
  • a control device such as a timer or switch, and
  • a component, such as a light bulb or motor, called the load which offers resistance to the circuit.

Wires act as the conductor, carrying electric current from the power source to the component. To provide and element of control, a switch of some sort is normally installed. And lastly, a safety device such as a fuse or breaker is used to protect against trouble.

There are three basic problems that can occur with an electrical circuit:

  1. a shorted circuit,
  2. a grounded circuit, or
  3. an open circuit.

Simple. The key is to learning how to read the signs.

Shorted circuits, grounded circuits, or open circuits can all occur within the conducting wire, component, or a control device such as a switch, thermostat, or timer. Let’s take a look at this basic circuit, enclose it in a grounded cabinet, and use it to demonstrate the three most common types of circuit problems that can occur.

First, a shorted circuit.

A short circuit happens when two bare conductors come in contact with each other. The current no longer flows through the entire circuit. It is shunted from the hot conductor to the neutral conductor and bypasses the load.

When this occurs there is only a very small amount of resistance in the circuit. According to Ohms law, for a constant voltage, represented by “E”, when resistance is lowered, “R”, the flow of current, or amperage, goes up, represented by “I”. This increase in current flow can cause the wires to heat up and is the most common cause of electrical fires.

Because the circuit is properly protected, the fuse, or circuit breaker, reacts to this increase in current, or amperage, and blows or trips stopping the currents ability to flow. To correct a short, the damaged conductors, or component, must be located and repaired. Then the circuit breaker can be reset or the fuse replaced. That was easy!

So now let’s look at a grounded circuit.

Grounded Circuit

It is a common safety practice to connect the cabinet of an appliance, or other major components, to a ground source. Electricity will always take the path of least resistance to ground. You do not want to be that path. So, this connection helps to protect the user from electrocution in the case of a short.

A grounded circuit happens when a hot wire comes into contact with a cabinet or a grounded part. When this happens, the circuit is again shunted to a neutral connection, in this case ground, the load is bypassed, the resistance decreased, the amperage increased, and you know the rest.

See, it’s pretty simple. We locate the problem, fix it, reset the breaker or replace the fuse, and bingo, you’re back in business.

Lastly, an open circuit.

An open circuit happens when a conductor, or component, breaks or burns out, opening the circuit and blocking electricity’s ability to flow. When this happens, resistance is increased so, according to Ohms law, current must decrease.

An open circuit is just like opening a control switch. No current is allowed to flow. This is the most common type of electrical problem associated with appliance repair. If any part within the circuit fails, the continuity, or electricity’s ability to flow, is broken, stopping the flow of current. Replacing the defective circuit component, or conductor, will get you going again.

At this point a few questions need to be asked:

  1. How do I know which of the three types of problems I’m dealing with?
  2. Once I know what I’m dealing with, how do I locate it?
  3. Lastly, once I’ve found the problem, how do I fix it?

There are a few things you can do right off the bat.

First, buy a volt meter if you don’t have one. A volt meter is a very inexpensive tool that will pay you back ten fold if you learn how to use it.

Understanding the basics of electric circuits can go a long way in allowing you to help yourself when it comes to many common problems around the house, including dealing with a wide variety of home appliance repairs.  Not that you’ll be able to do everything that a professional repair tech can do, but you will be able to save yourself some money on house calls.

Plus, when you do need to have someone with professional training come out and help you, you’ll be able to ask relevant, intelligent questions, and you might even be able to mooch a bit of free education off of them as they go about doing your repair.  I always love doing that (both sides of the equation, actually – both the mooch and the teacher! Lol).  It’s a great way to learn more… watch over the shoulder as someone with more experience does what you can’t do on your own.  It’s not only the way I got into the fixing things, including appliances, way back when I was a kid, it’s also an attitude I look for in all the technicians I hire at Appliance Masters – someone who is equally interested in learning as they are in teaching. Because we can all always learn from one another.

So anyway, there are a few techniques used for identifying what kind of problem you are dealing with when it comes to electric circuits, and point you in the right direction to locate it. There are two main types of circuits having the same key elements: A power source, conductors, load, and a control device.

The two types of circuits are series circuits and parallel circuits.

Series circuits are formed when two or more components, or loads, which offer resistance to the circuit, are replaced in series. When a problem such as the ones I described earlier happens, the entire circuit fails.

The other style, a parallel circuit, is when two or more components or loads are placed in parallel. In this style of circuit, depending on where the problem occurs, one component may fail while the other components remain unaffected. Many appliances use circuits that have both styles in one circuit and this is called a series parallel circuit.

Now you may be saying, “You said this was easy!” Anything worth doing takes some time and practice to master.

Now you know the four key elements of a circuit and the three most common problems that can cause your appliance to call in sick. This is a solid foundation of information to get you started.

Most appliance problems happen when a particular component fails to work properly, or a control device, like a thermostat, door switch, or timer, fails to open or close when it should. Each of these component failures gives clear signs as to the cause of the problem and where to start looking.

The easiest way to troubleshoot most appliance problems is by these symptoms, such as a dryer that will run with no heat, a refrigerator that is cold in the freezer but not the fresh food section, a washer that does nothing when it should spin, or a dead dishwasher.

These clues will tell you where to look, and with a little practice you are well on your way to experiencing the satisfaction that comes from solving your own home appliance problems.