Power Strips

Power Strips: Expanding Power Outlets

A power strip, often called an extension block or power bar, allows multiple devices to be connected to a single wall socket. They are especially practical in situations where extra outlets are needed. In addition to basic models, there are various types available, each with their own advantages:

• Standard power strips: Available in variants with different numbers of sockets, for example from 3-way to as much as 12-way. They are suitable for devices with low to medium power usage, such as chargers, lamps, or computer monitors.
• Power strips with switch: To manage energy consumption, some models have a central on/off switch that controls the power supply to all connected devices at once. For more control, there are options where each socket can be switched individually.
• Power strips with USB ports: Modern power strips often integrate USB-A and USB-C ports for added convenience. This allows mobile devices like smartphones and tablets to be charged directly, without the need for extra adapters. Some versions support fast charging technologies such as Power Delivery (PD).
• Surge protection: To protect sensitive electronics, power strips with built-in surge protection are available. These minimize the risk of damage from unexpected voltage spikes in the network.
• Special models: There are also specialized power strips, such as wall-mountable variants, compact desktop models, or strips with a flat plug, handy for placement behind furniture. For outdoor use, a power strip with a suitable IP rating is essential.

Extension Cords: Bridging Distances

An extension cord is used to bridge the physical distance between a power outlet and an electrical appliance. It consists of a flexible cable with a plug on one end and a socket on the other. The right choice depends on the required cable length and the power of the connected devices.

Length and Cable Thickness: Effects on Power Transmission

Extension cords come in various lengths. The length and especially the thickness of the copper wires (core thickness, expressed in mm² or AWG) determine the maximum power that can be safely transmitted. A thicker cable (lower AWG number, higher mm²) can carry more current and is more suitable for heavy-duty appliances and longer distances. The table below shows the indicative capacities:

Voltage drop may occur with longer cables. Choose an appropriate thickness for the required length and load.

Extension Cords for Indoor and Outdoor Use

Outdoor extension cords are specifically designed to withstand various weather conditions. These cables are recognizable by their robust rubber or neoprene coating and a higher IP rating (at least IP44). The most common types that handle different loads and environments include:

• H05RR-F: A lighter rubber cable, suitable for limited mechanical stress. It’s a good choice for household appliances and light tools, and can temporarily be used outdoors under minimal stress.
• H05RN-F: A sturdier rubber cable with a neoprene sheath. This cable is more resistant to oil, chemicals, and greater mechanical stress. It’s suitable for kitchen appliances, medium-duty industrial tools, and outdoor use with minor chemical exposure.
• H07RN-F: This is the heavy-duty rubber cable, designed to withstand heavy mechanical loads, oil, chemicals, UV radiation, and harsh weather. It is typically used on construction sites, in agriculture, and for mobile power needs where durability is crucial.

For more in-depth information on protecting electrical devices from external influences, see our article on IP ratings and cable types for outdoor use.

Cable Reels: Power and Storage for Long Distances

Cable reels offer an organized solution for using and storing long extension leads. They often feature multiple sockets and are particularly practical on construction sites, in large gardens, or at events requiring flexible and powerful electricity supply.

Important Features and Considerations for Reels

• Wind and unwind mechanism: The reel’s design makes it easy to neatly roll and unroll the cable, minimizing tripping hazards and extending cable lifespan.
• Thermal protection: Many reels are equipped with built-in thermal protection that interrupts the power if overheating occurs. This is a vital safety feature as a coiled cable under load may overheat due to the so-called 'coil effect.' For appliances above 1000 watts, always fully unwind the cable reel before use.
• Robust construction: Professional reels often have a sturdy metal or impact-resistant plastic frame. This provides resistance to intensive use and various environmental factors.
• IP rating and certifications: Pay attention to the IP rating, especially for outdoor reels. An IP44 rating means splash-proof. Products with CE, KEMA-KEUR, GS, VDE or TÜV marks guarantee quality and safety.

Safe Use of Power Distribution: Practical Tips

Regardless of type, safety is paramount when using power strips, extension cords, and reels to prevent risks of overload and fire. Following these tips promotes a safer working environment:

• Avoid overloading: Always check the maximum wattage that the power strip, extension cord, or cable reel can handle. Add up the wattage of all connected devices. If this exceeds the capacity of the item or the electrical circuit, overheating, short circuit, or fire may occur. High-power devices (such as kettles, heaters, power tools) should be plugged directly into a wall socket wherever possible.
• No 'daisy-chaining': Never connect multiple power strips or extension cords together. This greatly increases the risk of overload and danger.
• Correct environment: Use extension cords and power strips indoors only in dry environments. For humid areas or outdoors, only products with the proper IP rating (at least IP44 for splash-proof) are suitable.
• Check for damage: Regularly inspect cables and housings for cracks, wear, melted spots, or discoloration. Damaged items should not be used and must be replaced.
• Fully unwind reels: Always fully unwind cable reels before use, especially with high-powered devices. This prevents heat buildup in the coiled cable.
• Temporary use: Power strips and extension cords are intended for temporary use. For permanent power points at a location, having a fixed wall socket installed by a certified electrician is the safest solution.
• Cable management: Keep cables tidy and clear of walkways. Avoid running cords under carpets or through doors, as this can cause heat build-up and cable damage.

For general guidelines and more information on electrical safety, see our article on electrical safety at home and in the workshop.

Choosing the Right Installation Material

Selecting the right power strip, extension cord, or cable reel depends on your specific needs. Consider how many connection points are needed, the total power demand of the connected devices, the distance to be covered, and the environment (indoor or outdoor). A thoughtful choice ensures reliable power wherever needed.