Abstract: An enclosure for housing electrical equipment includes a bottom part, a wall part and a roof part. The bottom part, the wall part and the roof part define an interior chamber for housing the electrical equipment. The wall part includes at least one first air channel connected to the interior chamber, and the enclosure includes at least one fan for circulating air from inside the interior chamber through the at least one first air channel. The bottom part includes at least one second air channel connected to the interior chamber, and the enclosure includes at least one fan for circulating the air from inside the interior chamber through the at least one second air channel.

Abstract: An electronic apparatus includes an extruded metallic frame with walls which are integrated parts of the extruded metallic frame, at least one extruded flow channel in at least one of the walls for passing a cooling fluid within the respective wall, an inlet arranged outside the electronic apparatus and an outlet arranged outside the electronic apparatus for providing a flow path via the at least one extruded flow channel, and detachable covers which are attached to the walls for sealing off at least one electric component space from an outside of the electronic apparatus.

Abstract: A method and apparatus are disclosed for monitoring accumulation of dirt on an air filter of a ventilation system including the filter and a fan controlled by a frequency converter. An initial value for an operating parameter is determined. A present operating point is determined based on a characteristic curves, and the mechanical power and rotational speed of the fan. A present value for the operating parameter is determined based on the present operating point, and accumulation of dirt is determined on the air filter based on the initial and present values of the operating parameter.

Abstract: A method and an arrangement are provided in connection with a photovoltaic power generator composed of series-connected photovoltaic modules. The method includes determining a maximum power point voltage (UMPP) and a maximum power point current (IMPP). The method also includes determining the ambient temperature (Tamb), calculating an estimated maximum power point voltage (Uest) by using maximum power point current (IMPP) and the determined ambient temperature (Tamb), comparing the estimated maximum power point voltage with the determined maximum power point (UMPP), and determining on the basis of the comparison whether the generator is operating under uniform conditions or in conditions with two maximum power points.

Abstract: A method is provided for detecting the correct rotational direction of a centrifugal apparatus. The method includes rotating the centrifugal apparatus in a first direction, acquiring first frequency data relating to the step of rotating the centrifugal apparatus in the first direction, rotating the centrifugal apparatus in a second direction, which is opposite to the first direction, and acquiring second frequency data relating to the step of rotating the centrifugal apparatus in the second direction. The method also includes detecting the correct rotational direction of the centrifugal apparatus based on comparing the first frequency data with the second frequency data, the comparison being carried out with respect to at least one significant frequency range. In each of the at least one significant frequency range, a smaller magnitude is interpreted as an indication of the correct rotational direction.

Abstract: The disclosure relates to a gas permeable wall for preventing dirt present in a gas flow from passing through the gas permeable wall with the gas flow. In order to minimize maintenance, the gas permeable wall is a circumferential wall of a cover, and an outlet from the cover is provided for passing on gas having entered the cover through the circumferential gas permeable wall. A support is provided for attaching the cover rotatably to a device, and a drive unit is provided for rotating the cover.

Abstract: A method and apparatus for optimizing energy efficiency of a pumping system includes at least one pump that controls a fluid level in a reservoir. The method includes a system identification stage and an energy efficiency optimization stage. The system identification stage includes determining pump characteristics for the pump, operating the pump with a range of flow rate conditions, determining a set of data points, and calculating energy efficiency optimization characteristics. The energy efficiency optimization stage includes determining a present static head value, choosing a value for a pump control parameter, and operating the pump on the pump control parameter.

Abstract: Method and apparatus of splicing a paper web, in which a paper web from a new reel is spliced to a paper web from an emptying reel and a position of glue or two sided tape in the surface of the new paper reel is marked. The method includes receiving a command for splicing, determining the splicing time instant, accelerating a rotation of the new paper reel, detecting the glue or tape, controlling, based on the detected glue or tape, the rotation of the new paper reel in such a manner that the rotation speed of the new paper reel and the position of the glue or tape are as required at the splicing time instant, and splicing the paper web at the splicing time instant.

Abstract: A method and arrangement are provided for reducing the amount of condensed moisture inside an enclosure which encloses at least one piece of electrical equipment which is configured to receive electric power from outside the enclosure in a first electrical magnitude range (0 . . . maxinput) and to feed electric power to outside the enclosure in a second electrical magnitude range (minoutput . . . maxoutput). Electric power received on at least one portion (a, b, c) of the first electrical magnitude range (0 . . . maxinput) being outside the second electrical magnitude range (minoutput . . . maxoutput) is utilized for heating the condensed moisture for exhaustion thereof.

Abstract: A capacitor fastening for fastening a capacitor to a panel, whereby the capacitor, when mounted in place, is positioned in the panel, fastened at its lower part. The capacitor fastening includes a retainer in the panel at the mounting point of the capacitor for preventing lateral movement of the capacitor in at least one selected direction; a tightening plate arranged above the panel and to be fastened to the panel, which tightening plate has a hole substantially corresponding to the diameter of the capacitor above the mounting point of the panel; and a wedge between the panel and the tightening plate for tightening the retainer of the panel and the edge of the hole in the tightening plate from opposite directions against the capacitor.

Abstract: The disclosure relates to a motor drive including electric power supply devices for supplying electric power to an electric motor, a memory for storing parameters, a controller for controlling the power supply according to the parameters stored in the memory, and an interface for connecting a computer to the motor drive. In order to enhance configuration of the motor drive, a configuration program is stored in the memory, and the interface provides the computer with access to the memory for executing the configuration program with the computer and for changing the parameters stored in the memory with the computer executing the configuration program.

Abstract: A method and controller for operating pumps wherein each pump is modelled by a QH model indicating a high-efficiency region, a high-H region and a high-Q region and a rotational speed limit. A controller dynamically maintains a current set of operating pumps and controls their rotational speed (n). In steady-state operation, wherein the pumps operate in the high-efficiency region and below the rotational speed limit, all pumps of the current set are controlled together. If the pumps operate in the high-Q region or beyond the speed limit, a new pump is added to the current set, started and brought to a speed that produces flow. A balancing operation (12-3) follows the pump addition operation, wherein the speed of the pumps of the current set are adjusted for equal heads. If the pumps operate in the high-H region, a pump is removed from the current set of pumps.

Abstract: A stator winding is disclosed for a multiple-phase alternating current machine with several parallel winding groups (U1, V1, W1; U2, V2, W2; U3, V3, W3), each of which can be supplied with separate power sources. Locations of the winding groups can be cyclically shifted when moving from one pole to another. The number of parallel winding groups (U1, V1, W1; U2, V2 ,W2 ;U3 ,V3 , W3) can be higher than two, and the number of poles of the alternating current machine can be an even figure that is a multiple of the number of winding groups.