Volts vs. Amps: How Much is Enough for Your Home?

How does a homeowner, or someone looking to buy a new home, determine if they have enough electrical power available?

To do that you will need to verify 2 things in your electrical system, the voltage rating and the available amperage. Voltage is the amount of electrical power available and amperage is the amount of current or flow available. If you compare electricity to water, voltage would be the amount of water pressure (think about that shower that has too little water pressure) and amps is the amount of water flowing (think gallons per minute)

How many volts do I need?

Modern homes are built with a 240 volt supply. If you own, or are buying, an older home it may only have 120 volts. If this is the case, unless you plan to live alone and not use many electrical appliances you will need to upgrade the electrical supply.

How many volts do I have?

To determine the voltage rating of your home, the easiest place to look is your electrical meter. Another option is to look for the number of wires that enter the conduit attached to your home (if your electrical lines are above ground). 3 wires indicate 240 volts and 2 wires indicate 120 volts. If your electrical supply is below ground you can assume you have 240 volts available.

How many amps do I need?

This questions is not as easy to answer and will depend on the size of your house, the number of electrical appliances and how many people are living in the home. Here are some general guidelines; your situation may require less or more amperage:

60 amps for a 3 bedroom house with all gas appliances (dryer, range and water heater)

100 amps for a 4 bedroom house with electrical appliances (dryer, range and water heater)

Note: add 50 amps to the above if central air conditioning is included and 200 amps for homes with electric heat.

How many amps do I have?

If your home has circuit breakers the amperage is typically marked on the “mainapostrophe breaker usually located at the top of breaker box. If your home has fuses the amperage will be marked on the fuses that are located underneath the fuse block marked “mainapostrophe. A 100 amp system will have 2 fuses each marked 100 amps.