Multiple plug outlets must be plugged directly into mounted electrical receptacles; they cannot be chained together. Make sure the extension cord or temporary power strip you use is rated for the products to be plugged in, and is marked for either indoor or outdoor use.
Another difference between indoor and outdoor extension cords is the plug type used. Many indoor extension cords have a two-prong plug, and outdoor extension cords come with a three-prong plug. A three-prong plug is only used with an outlet that has a ground slot.
The thicker the copper wire, the more electricity it can carry. However, because transmitted power diminishes over distance, longer extension cords require heavier wire to deliver the full current rating required by an appliance. The wire can never be too big, but it can be too small.
It does not matter if they plug direct or by an extension cord. The key is not to draw too much power. I use it to plug in a desk lamp, pencil sharpener, the transformer for a desk phone and multiple cell phone chargers. It does not matter if they plug direct or by an extension cord.
Do not run extension cords through walls or ceilings. This may cause the cord to overheat, creating a serious fire hazard. Do not nail or staple electrical cords to walls or baseboards. Make sure that cords are not pinched in doors, windows, or under heavy furniture, which could damage the cord's insulation.
Unfortunately,once in place, extension cords tend to become permanent wiring and a fire hazard. Solutions: Several safe solutions exist. In many cases, a power strip energized by an extension cord or another power strip can simply be replaced by a power strip with a power cord of adequate length to reach an outlet.
Disconnect the power plug (by pulling the plug, not the cable) if the power cable or plug becomes frayed or otherwise damaged. It is dangerous to handle the plug with wet hands. Doing this may result in receiving an electric shock. Unplug the power cord from the wall outlet before you move the machine.
Extension cords that are not listed, labeled, or rated for permanent (long term) use are all temporary wiring devices. If you need to permanently connect an electrical device, you should use approved wires and/or cable assemblies installed in an approved manner.
Extension cords are only for temporary use and are not to be left plugged into wall outlets when not being actively used. This plugs into a wall outlet and is considered a power strip even though it doesn't have a cord. Do not plug an extension cord or power strip into it.
Take the time to choose the proper extension cord for the equipment being used. Damage may not be visible at first glance. Extension cords must be plugged directly into wall outlets. Do not “daisy chain,” that is, plug extension cords into surge protectors or other extension cords (see photo 9 below).
Temporary wiring is not to be used as permanent wiring. For example, there is a 90 day limit for an extension cord and other temporary wiring devices used for holiday lighting at a given location, as established by the NEC and by OSHA in its electri- cal standards.
Match your cord to the work environment, whether indoor or outdoor. Outdoor-rated cords have durable covers to protect from weather and damage. You can use an outdoor-rated extension cord inside; however, using indoor power cords outside could lead to overheating or exposure to moisture.
Not Safe—Daisy Chaining Power Strips. The proper use of a power strip usually does not cause a hazard. It's the improper use that can cause safety issues, such as creating a potential electrical failure and/or a possible fire hazard. An example of using power strips unsafely is when they are “daisy chained” together.
If a power strip has 10 outlets, it's safe to assume you can go ahead and use them all, right? Not necessarily. This means plugging one power strip into another power strip to markedly increase the number of outlets. Power strips are not designed to be used this way, and doing so can result in a fire.
Its generally suggested not to use an extension cord for a permanently plugged in appliance like a refrigerator. If you must a refrigerator can draw a peak power of 4 to 8 amps when cycling on and you should use one with a 3-conductor (grounded) 16 ga. and have jacketed cable for protection (not the zip cord ones).
Most modern residential circuits are 15 or 20 amps, so we're looking at a max load of either (15A x 120V =) 1800 watts or (20A x 120V =) 2400 watts before the breaker trips. The breaker will be labeled either 15 or 20.
Extension Cord Ratings
|Extension Cord Wire Gauges, Amperage Rating, and Wattage|
|Wire Gauge||Amperage Rating||Wattage Rating|
|#18||5 Amps||600 Watts|
|#16||7 Amps||840 Watts|
|#14||12 Amps||1,440 Watts|
A power strip (also known as an extension block, power board, power bar, plug board, trailing gang, trailing socket, plug bar, trailer lead, multi-socket, multi-box, multiple socket, multiple outlet, polysocket and by many other variations) is a block of electrical sockets that attaches to the end of a flexible cable (
Orange electrical outlets carry a universal meaning in the electrical world: it's an isolated ground receptacle. In addition to being orange, these outlets typically have a green triangle marking. A green dot specifies that it's a hospital-grade isolated ground outlet.
The red outlets (sometimes referred to as sockets) in hospitals and medical facilities indicate that they are on emergency backup power. The bright red color helps nurses, doctors, and hospital staff quickly and clearly identify where to plug in critical equipment during an emergency situation.
Black, Red and Blue are used for hot wires and White is used as the neutral wire in a 120/208 V circuit. Brown, Orange and Yellow are used as hot wires and gray is used as the neutral wire in a 277/480 V. For grounding, regardless of the voltage, Green is used.