FAQ Power strip

Topic: USB Hub

A USB hub is a device that distributes a USB signal to multiple USB ports. USB hubs can draw the power they require from the bus itself (bus-powered) or from its own power source, usually in the form of an external power adapter (self-powered). Self-powered hubs offer the advantage of being able to connect and power a device using up to 500 mA. Bus-powered hubs allow the hub and all of the devices connected to it to consume a collective maximum of 500 mA. The USB standard provides for the connected devices to start up in low-power mode (100 mA) and then when a higher level of power is required, they request a higher amount of power from the host before they switch into normal mode. In the case of USB 2.0, that can be up to an additional 4x 100 mA. If this requirement is not fulfilled, the device must switch itself off. If a hose (PC) is not connected, the USB ports will not be released as per USB specifications. Many USB users however, use the USB connection only as a power source and thus do not adhere to the USB standard because they request the use of more than 100 mA. This is only possible with USB hubs that do not adhere to the USB standards. In this case, the upstream (host) Bus power supply is short-circuited internally with the external power supply which does not conform to the specifications. The same 5 V supply is then connected to the downstream port without protective elements. That can, in extreme cases, damage the host’s (PC) USB connection or disturb the energy management of the computer, which can lead to instable behavior. Brennenstuhl products with USB hubs, however, adhere to the USB specifications in order to avoid this kind of damage.

What do the references to the inserts in power strips / adapters mean?

Essentially it deals with a regulation by the technical surveillance authority, which demands that all manufacturers of power strips / adapters mention this information. (VDE 0620-1) 1: do not insert in a series” power strips (multi-outlet power strips)/adapters should not be connected in a series. The reason is the increasing danger of overloading by more sockets, an additional contact transfer resistance and the associated fire hazard, as the strips are only suitable for specified power consumption. 2: “Do not operate covered” Power strips adapters should not be operated when covered. The reason is the danger from heat build-up and the accompanying fire hazard. 3: “connector volt-free only when drawn out ” Safety instructions: the power strip is voltage-free only when completely unplugged! Our power strips with switches turn off the 2 poles of stripe. This means that the strip is voltage-free when the bar is unplugged and the power switch is turned off. For safety reasons the power plug should be always be pulled before working on electrical equipment.

What connector systems are available through Brennenstuhl®?

Brennenstuhl® connector systems can be delivered to more than 150 countries around the world. You can find a detailed overview in the attached list.

How much electricity / power can be drawn from a power strip?

Basically our power grid/network in Germany is fused for 16 amperes. At 230 volts you can then take max. 230 V x 16A = 3.680 watts. Accordingly, all power strips are loadable with this power, except for, if corresponding instructions (on the type plate) specify a limited max. power rating. For example, through an integrated 10 ampere fuse.