Power socket for a frequency converter
Publication Date: 2002-Jul-31
The IP.com Prior Art Database
Installation and service of frequency converters are improved by using a power socket. The power socket is mounted to a wall, and motor and mains cables are connected to terminals inside the power socket. Then the frequency converter is put on top of the socket. The socket may incorporate a metallic plate for earth connection, or it may incorporate a fan or a repair switch.
Power socket - A new way to install cables on a motor drive
This document describes a new installation concept for central drives in the lower end of the power range. It covers cable installation, decoupling and connection to a motor drive such as a frequency converter. The Power socket is an "add on" to the frequency converter. Such "add on"s are e.g. known from US 5,752,838. Further, US 6,320,776 describes the use of a terminal block in a frequency converter, as does US 5,598,328. In a manual "Bosch Servodyn-D", the firm Bosch has also described a socket containing terminals for a motor drive, the socket being placed on a wall and the motor drive pushed into the socket.
The "Power socket" idea has its roots in a demand to improve user friendliness by fast replacement of failing units, by better and easier EMC decoupling and good mechanical relief of installation cables on the frequency converter. The idea about fast replacement of failing units comes from a frequency converter type FCD 300 where all cables are installed just once. In the case where the electronics breaks down, a top part is rapidly replaced without long stop in production.
Cables are installed in the bottom part
The top part is replaced in case of brake down
Figure 1 - FCD 300 with top and bottom part
The power socket is adapted to a standard frequency converter, and is an option to the frequency converter. As will be shown, the socket - besides the terminal function - also incorporates a load- bearing function as the frequency converter is mounted on top of it.
The frequency converter is replaced in case of breake down
Motor- and mains cables are installed in the bottom part
Figure 2 - The new Power socket - a frequency converter is mounted on top of it.
When using this concept it must be made sure, that the future products are backwards compatible especially in size (footprint), i.e. that old costumers which are not interested in using the "Power socket" also in the future can use the products. One has to consider the space available under the frequency converters mounted in the existing installations.
Also, the costumers demanding "Cold plate" and "Durchstecker" (Flanged heat sink) frequency converters shall be considered. They could get "Power socket" in shorter version (without the back part - the apparatus with forced convection use it just as air channel). In these cases "Power socket" would be used as a kind of plug block because these apparatus ("Cold plate" and "Durchstecker") are first to be mounted on/through the wall of the cabinet, but there is still the possibility of installing the Power socket on the wall at first, and then sliding a frequency converter down on the socket. One has to remember that cold plate units still have to be fastened thoroughly to the wall (contact plate) because of heat transfer.
Expected areas of improvement
We expect the following areas t...