Practically all of your listings will have an electrical system. Whether working with buyers or sellers, it pays to understanding the basics.

These days, every house or apartment is going to have an electrical system of one sort or another. Understanding the basics of these systems will help you evaluate homes and knowledgeably answer questions from prospective buyers.

Electricity typically is generated at a power plant and travels to transformers, which lower the voltage to a level that local distribution systems can handle. From there, electricity travels over local distribution systems to individual homes.

One problem in this method of delivery is that quite a bit of electricity is lost in the process of traveling from the plant to its final destination. An alternative is generating electricity on site by solar electrical systems, wind turbines, or generators.

So what else do you need to know about electric systems? While it's best to leave the big questions to electricians, these are some basics that you should know.

1. Does the home have 220 volt service?

If the home was recently built, the answer is almost always yes. Most houses today have two 110 volt wires and one neutral wire running into the house from the local distribution system. These wires can run underground or above ground. If there are two 110 volt wires running to the house, then the house has 220 volt service and appliances, such as dryers and air conditioners.  

Older houses were usually built with 110 volt service; if the electrical system hasn't been upgraded, it won't be possible to use some models of appliances (though alternatives can be found).

It's possible to upgrade a house from 110- to 220-volt service. How much it costs to upgrade will depend on the particular house and the location. If a buyer is interested in upgrading, an electrician can give an estimate for what the work will entail.

2. What's the difference between a fuse and a circuit breaker?  

Fuses and circuit breakers are both found in the electrical panel (or sub-panel) of a house. They both serve the purpose of cutting the flow of electricity when a circuit gets overloaded-a potentially dangerous situation. Circuit breakers will be found in most houses built after the 1960s or in older buildings that have had their electrical systems upgraded.  

Fuses have a thin strip of metal that literally blows when there's too much electricity flowing through it. When this happens, the fuse needs to be taken out and replaced.

Since the 1960s circuit breakers have been used instead of fuses. They are more convenient, as they just need to be flipped back on if they are tripped. Unlike a fuse, they don't need to be replaced.

Both circuit breakers and fuses are rated according to how much electricity can flow through them before they trip and shut down the circuit. A 15- or 20-amp fuse is typical for regular light fixtures and such. If the right fuse or circuit breaker isn't used, it can cause a dangerous situation. Clearly, if a fuse or circuit breaker becomes problematic, an electrician should be called in to look at it.

3. Where's the main panel?

This is where all the circuits in the house originate from and it's usually near where the electric power enters the building. It will be filled with circuit breakers (or fuses in an older building). The main panel has a rating that determines the total amount of current that can flow out to the circuits at one time before the main circuit breaker shuts the entire system down.

Most moderately sized older houses have 100 amp service, though a smaller house might only have 60 amp service. Larger new houses are often built with 200 amp service to accommodate all the electronics used these days. If a buyer is thinking of adding on to a house or just modernizing an older house, one consideration will be if the electrical system is big enough to handle the additional electrical requirements. It's possible to upgrade the main panel to handle more amps. Again, an electrician can give a buyer an idea of how much work this will be in a particular house.

4. Are the outlets grounded? 

These days most electrical outlets that you see accept three prong plugs. This means, almost always, that the outlet is grounded. A grounding wire, which connects to the round third hole, protects against electric current escaping from the circuit and causing shocks.

Older houses might only have two prong outlets, meaning there's no grounding protection in the circuits. Upgrading an electrical system to include grounding wires involves opening the walls and can be a significant amount of work. How much work it is depends on the size, construction and layout of the house.

GFI outlets (GFI stands for ground fault interrupter) are typically required by building codes when installing an outlet near a water source or a damp location. These are the three prong outlets that have two buttons on them reading test and reset. Since water and metal handles and spouts conduct electricity, it makes a ground fault particularly dangerous in wet locations such as a bathroom. A ground fault is where the electricity goes astray despite the grounding wire. If this happens the GFI quickly cuts the power. GFI outlets are also called GFCI, or ground fault circuit interrupter.

Knowing how to talk the talk about a listing's electrical system will help to put a little spark in your sales pitch. The important thing to remember is that for a price, electrical systems can be upgraded and expanded to meet the needs of the buyer as well as building code requirements.

Posted on August 2008.