Cascading multiple sockets
The number of electrical devices is constantly increasing in the private, professional and public sectors. In the office or home office, PCs/computers, 1 or 2 monitor(s), loudspeakers, printers and lights are usually connected to a multiple socket. As a rule, socket strips can handle a maximum load of 3680 watts (230V x 16A). If too many devices draw power from a multiple socket and the recommended consumption is significantly exceeded, there is a risk of fire. Connecting multiple sockets in series (cascading) is absolutely taboo, as the amount of electricity from the connected devices quickly add up to far too high a consumption and, if used improperly as defined by DIN VDE 0100 Part 420 Paragraph 4.1, represents a fire hazard in electrical systems. The situation is different with stationary multiple sockets. You can read about the conditions under which these can be cascaded or connected in series in the following article.
Is it forbidden to cascade / connect multiple sockets in a row?
Yes, the cascading of multiple sockets with household plugs (e.g. type F CEE 7/3, SchuKo®) is not permitted in Germany according to DIN VDE 0620-2-1:2016. The function of upstream safety elements cannot be guaranteed with multiple socket strips operated in this way. The standard requires the attachment of warnings to mobile multiple sockets ("Do not plug in one behind the other").
Can non-changeable / stationary power strips be cascaded?
Stationary mounted multiple sockets with extension option in the passage level - power input and power output via installation plug connector according to EN 61535 - can in principle be cascaded, since it is then a linear extension and not branches. Socket strips can be integrated as fixed equipment in a plug-in installation. The feeding of the system is not decisive for the possibility of cascading.
In terms of standards, multiple sockets with a passage level according to DIN VDE 100 are in fact interpreted as equipment, so feeding in via a type F plug is not an exclusion criterion for the cascading of multiple sockets. However, the power supply for the system supply line with plug type F must not be provided via another multiple socket.
When are multiple sockets considered fixed equipment?
In addition to installing the infrastructure in the building, socket strips must also be considered as equipment, which as such can also be part of the fixed installation. For equipment for fixed installation, the connection option must meet the requirements of the installation regulations in accordance with DIN VDE 0100 for fixed installation.
These requirements are met by integrating installation connectors into the multiple sockets. These can be regarded as fixed equipment if they are installed permanently and immovably (e.g. by means of clamping devices or screws) or remain inaccessible and immovable for the layman during normal operation. In this way, the installation can be extended to the maximum permissible cable length, provided that the total connected load of 3,500 watts and the maximum current of 16 A are not exceeded.
Which connectors are suitable as an interface to stationary equipment that is part of the fixed installation?
In principle, all certified installation connectors according to EN 61535 are suitable. The scope of this product standard for installation connectors is the permanent connection in the construction of electrical systems.
These requirements are also part of the DIN VDE 0100 Part 520 installation regulation. The use of installation connectors is therefore regulated in accordance with EN 61535.
At the product level, BACHMANN uses gesis® and GST18® from Wieland Electric as the standard interface in a plug-in installation.
Bachmann - STEP modular multiple socket strip
Bachmann's STEP socket units have a power input and a power output, each integrated in the end caps on the front. The built-in GST18 connectors from Wieland are particularly tried-and-tested connectors for office use and have the appropriate coding and connector latching in accordance with the valid standard. In addition, other plug-in connection systems can be implemented on request.
The modular socket strip STEP can be used in a variety of ways; for example for mounting under table tops, in cable ducts and partitions. Various fastening options are available for installation. In the online shop you can buy the different versions of STEP (base, aluminum, security modules). We would be happy to advise you by telephone or e-mail at F for questions about the multiple socket strips from Bachmann.
Checklist for the permanent installation of multiple sockets
- Professional
The installation is carried out by a qualified electrician or a qualified and cyclically instructed person. - Installation
The entire installation, including multiple sockets, the connecting and supply lines and plug connections, is not exposed to any mechanical stress. At best, equipment and cables are installed in accordance with the VBG/BSO “Guidelines for Electrical Installation in Office Furniture”. - Connector
All multiple sockets, the connecting and supply lines as well as plug connections are equipped with installation plug connectors according to EN 61535. - Local party
The components of the system are stationary (permanently, immobile or inaccessible). - Care
The system supply line is supplied via a type F plug on a permanently installed socket (flush-mounted, in the cable cable, floor box or similar), or via a permanent connection. - Standard
All relevant parts of the VDE 0100 series of standards are taken into account and demonstrably complied with (total cable length, type of laying, conditions for protection, etc.). - Impedances
The maximum permissible loop and mains impedance must not be exceeded in the overall system. - Resistance
The maximum permissible protective conductor resistance (< 1 ohm) must not be exceeded. - voltage drop
The maximum permissible mains voltage drop of -5% must not be fallen below.