Electrical Considerations for Additions, Hot Tubs, and Other Miscellaneous Add-ons
If you are looking to add on to your house, install a hot tub, or even put a window unit air conditioner in your home, you must first consider if your panel and your incoming electrical power can handle the demand. It is a common misconception that you can just simply add another circuit. Take for instance, if one has a panel that consists of fuses, typically, it does not provide the required amount of amperage, which is what is drawn from your electrical service to run everything in your house.
Light bulbs are usually .5 amps, while ovens, dryers, and air conditioners can use anywhere from 30 to 50 amps. If you have a 100 amp service, your 50 amp oven, 30 amp dryer, and 30-50 amp air conditioner are going to use most of that 100 amps, if they are all on at the same time.
Let us assume that you use said appliances all at one time. Jennifer is baking, Tom is washing clothes, and it is 150 degrees outside. You are not going to want to jump into your hot tub and run it. Lights will dim, you can damage computers, or, even worse, cause your panel to heat up and become damaged. Heat is the number one enemy of electricity. Although electricity produces heat, the components that comprise your household electrical system are designed only to handle minimal amounts of heat. If you have a 100 amp service, and you are using 120 amps on a regular basis, you are asking for your house to burn down.
If you think that you need a window unit air conditioner, and want to plug it into a simple existing wall plug, think again. You are going to have to determine what circuit that plug is on, what else the circuit is providing power to, and if the circuit can handle a big appliance such as the air conditioner. Window unit a/c’s can require anywhere from 15 to 20 amps by themselves. If you attempt to plug it into a 15 amp plug, the breaker will trip every time you try to run the a/c. It is at this time you must realize that you will need to add a whole new circuit especially for the a/c unit. If you have not purchased your unit yet, you can find one more suitable for the room, and determine which electrical hardware you will require.
And to save money, you can just buy the required outlet, faceplate, wire, etc. yourself. For reference, some units require 3 wires. Check the unit under consideration, if it is a 20 amp 220 volt unit you will need 12-2 wire, which is #12 gage, 2 conductors. If it is a 30 amp 220 volt unit you will need 10-2 wire, which is #10 gage, 2 conductors. For a simple 15 amp 120/220 volt unit, you will need 14-2 wire, which is #14 gage, 2 conductors. Your helpful hardware store employee should know this stuff.
So, you want to install a hot tub? You are looking at a $1500-$2000 job right there. And it’s pointless to put one in if your panel and electrical service can’t handle the power requirement. Now you are looking at a $4000-$5000 job, but in the long run will be worth it, because the panels manufactured today are more efficient, and have more room for expansion. Want to make it cheaper? Purchase the panel and breakers yourself!
What you want to do is look at your existing electrical panel and count the number of breakers/fuses, noting the ampacities as well (ampacities are normally located on the face of the breaker or fuse). With fuses it may be different, though. When you have a fuse panel, it is possible that you have multi-tapped fuses (using one fuse for more than one circuit).
90% of electrical companies tend to utilize a Square D QO type panel. These panels use circuit breakers with indicators on them so you can visually see if the breaker has tripped. Ask the store attendant to show you the proper breakers. The sizes range from 10-space 50 amp panels to 40-space 200 amp panels. Depending on how many breakers or fuses you are currently using you may need the full-40. But oftentimes you will only need a 30-space 200 amp panel. Remember to check with the electrical company to determine what your existing service is now. Your best bet is to get the 30-space 200 amp panel, just in case you are thinking of adding other equipment to you abode.
I will continue with the panel changing requirements at a later time due to the lengthy article it shall become. But as far as adding on goes, just remember, you cannot use power you do not have. In the long run, if you choose to continue adding on, just keep in mind the demand factor. Your electrical contractor is obligated to tell you about these things. If he fails to mention the dangers of adding on without upgrading your electrical system, I would not advise you to allow him to work on your house. Safety is a number one priority, and must be observed by all electricians at all times. Due to fire regulations which govern our National Electrical Codes, we are to be preventive maintenance specialists in the electrical scope.
