Using extension cords Don't plug multiple cords together. Don't run extension cords under rugs or furniture. Never tape extension cords to floors or attach them to surfaces with staples or nails. Don't bend or coil cords when they're in use.
Extension cords can overheat and cause fires when used improperly. Overheating is usually caused by overloading or connecting appliances that consume more watts than the cord can handle. Damaged extension cords can also cause fires. Extension cords should only be used temporarily.
Do match up the plug and extension cord on a polarized cord (one hole on the plug is larger than the other). Do keep extension cords away from water. Do use GFCI (ground fault circuit interrupter) protection when using extension cords in wet or damp environments. Do keep extension cords away from children and animals.
Extension cords always conduct electricity when plugged into an outlet, even if it is not being used. Therefore, always unplug the cord when you are finished with it.
According to the Energy Saving Trust, any switched on charger that is plugged in will still use electricity, regardless of whether the device is attached or not.
Having an extension cord on a bed isn't a likely hazard if the cord is in good condition and not overloaded. Modern electrical devices, including extension cords, have safety features tested to ensure they are safe for practical uses, even using one on a bed.
In general, extension cords should not exceed 100 feet in length. However, by plugging one extension cord into another, the maximum cord length can be easily exceeded. If the job requires more than a 100-foot distance, a temporary power distribution box is required.
The rule of thumb is to choose an extension cord that can handle more power (amperage, current) than your device requires. If you connect multiple devices, add their current requirements to calculate the maximum amperage of the cord you need. —That's the upper limit the extension cord can safely conduct.
It occurs most often in motion applications, where constant flexing and repetitive motions can cause stress and deform the cable, often destroying the core. As a cable moves within a cable carrier or on a robot arm, for example, its conductors also move, shifting from the original stranding design.
While it's fine to use an outdoor power cord indoors, never use an indoor-rated extension cord for an outside job— doing so could cause electric shock or create a fire hazard.
Source: CPSC. Consumers should immediately stop using male-to-male extension cords, according to the Consumer Product Safety Commission, which said that the products can cause electrocution, fires, and carbon monoxide poisoning.
Rating Indicator — Look for the letter “W” on the cord or on the packaging. That's the letter used to identify cords that are designed for outside electricity use. Insulation — Extension cords rated for outdoor use have additional insulation around the wires in the cord.
If any part of the extension cord is hot while in use, it is a warning sign that it may be overloaded. Check if the extension cord is properly rated for the products that are plugged into it. Also, inspect the cord along its entire length to ensure it has not been damaged.
Testing should be conducted on each piece of equipment every three months, as well as before first use or return to service after repair. In order to ensure a grounding wire is electrically continuous throughout the extension cord or power tool, a continuity test must be conducted.
Using extension leads safely
Power-hungry appliances such as kettles, toasters and microwaves shouldn't be on the same extension. Always use a fused 'inline' type – not the plug-in cube type – but be really careful not to overload it.
Use one extension lead per socket only, otherwise the risk of overloading the wall socket and the extension lead plugged into it!
How Do You Know How Many Things You Can Plug Into One Outlet? As a rule of thumb, it's safest to stick to a maximum load of 1,500 watts per outlet or circuit. The number of things you can plug into one outlet depends on the wattage of each device or appliance you want to plug in.
The appliance draws a current higher than the ampacity of most extension cords. This will heat the cord and is a fire risk. The length of the cord could result in a voltage drop which the appliance cannot tolerate.
Thankfully, an extension cord is a pretty basic device with no complicated circuity inside, so you should expect minimal or zero damage if your extension cord got wet, so long as it's powered off quickly and dried off completely before usage.
When you leave your charger plugged in, even if your phone is not connected to it, the charger is still using power from the outlet. This means that all of that wasted energy is going into heating up your home and making the air more polluted.