When installing appliances or working with heavy tools you should take special precautions to use the properly rated extension cords.
Tools like Air Compressors, Welders and appliances like Stoves, Washers and Dryers will use a lot of amperage. If the extension cord you use is not thick enough the cord will heat up and could cause a fire.
A simple method for getting the AMPs your item uses is
WATTS / VOLTS = AMPS
So if you have a 400 watt power supply on your computer and it is running on regular 110 volt home power.
Divide 400 by 110 and you get 3.6 Amps
This means on a 15amp circuit you could run 3 computers safely.
but that does not account for Monitors and Printers and Desk lamps.
|
||||||||||||||||||||||||||||||||||||||||||||||||
You will notice 2 factors above. First the more amps needed the thicker the cord must be. Also the longer the cord the thicker the cord must be.
So even though you are using a small appliance if it is far away you will need a thicker cord.
If you are using a 15amp Circular saw and you are 200 feet away from your power source you better get the thicker 10amp cord even though it costs a bit more. For one thing on a cheap 14g or 12g wire your saw won’t have the power it needs and if you are using it constantly the cord will heat up and start to melt over time the cord won’t last.
This also means that if you are using a cord that is longer then you need say a 100 foot cord but you are only 20 feet from the outlet then you still need a thicker extension cord thats rated for 100 feet not the 20 actual feet.
One example of using an under sized extension cord came up when I purchased a larger air compressor. My previous compressor was rated at 2.5 hp and my new one was 5hp. Because I needed to use the compressor immediately and it was a replacement midway through a job I just plugged the new compressor into the same heavy line that I already had on site. While using the new compressor to spray paint I heard a thumping noise. I looked behind me and saw that a magnetic field was causing the extension cord to jump off of the ground about 2 feet every time the compressor started. I felt the wire and it was warm so I immediately replaced it with a different cord.
You can think of this kind of like hooking your garden hose up to a fire hydrant. Sure it may work for a few minutes but soon everyone is getting wet. Unfortunately electricity is not as kind as water.
Another problem happened when I was powering a 2.5hp compressor to run some brad nailers for trim work. Two 12g lines were used to reach about 200 feet to the house then airlines were used to run inside the house. About once an hour the compressor would kick out and it was a 2 week old compressor. Finally we ran a 200 foot piece of 10G romex with boxes on it from the generator to the compressor and the problem was solved. The Compressor wasen’t getting enough power and it started to fail.
Using this under rated cord outside would not have been an extreme problem if failure occurred. Maybe the cord would have melted and caught fire but being on dirt and road surface no other damage would have occurred. Except maybe to our equipment.
If you are powering an appliance in your home the failure of an extension cord could mean a fire in your house.
Never stack or overload power strips on an extension cord.
Power strips for Computers are to be used for one main appliance and intermittently for other appliances like printers. For instance do not plug 5 electric heaters into a power strip.