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Mechanic Design

General design

The alternators consist of the main internal-pole generator and the external-pole exciter machine. The entire design is configured for highest reliability, quality and durability.

Stator and bearing housings

The stator housing is a solid welded construction. The stator core is made up of low-loss laminations, pressed together by means of pressure plates to form a compact unit.

The stator insulation system is based on temperature class “H” materials for low voltage alternators and class “F” for medium voltage alternators, according to EN 60034-1 / VDE 0530-1. The winding overhangs and connections are supported by fastening elements and firmly linked by mechanical means to guard against loads caused by electro-dynamic forces. An auxiliary exciter winding located in the main stator slots provides power to the automatic voltage regulator. The exciter machine stator is fixed in the non-drive end bearing housing.

The bearing housings are also made of rigidly welded construction with integrated machine feet, in order to ensure a perfectly stiff fixing to the foundation.

Rotor and bearings

The main salient-pole rotor is made up of steel laminations or steel plates that are hydraulically pressed together. A copper damper cage, electrically interconnected within the pole shoes and from pole to pole, is installed as standard. The main salient-pole rotor winding is made from copper profile and protected against deformation caused by centrifugal forces by suitable and generously sized spread supports. The exciter rotor consists of dynamo lamination with the three-phase winding incorporated into its slots.

The rotor windings comply with temperature class H in accordance with DIN EN 60034-1 and VDE 0530-1. As a standard for all frame sizes, high-quality sleeve bearings are used. Depending on operation mode and speed, oil cooling by embedded water cooling snakes or by separate oil supply system can be arranged. Case-related, at small machines or at some vertical designs, also antifriction bearings or a combination of sleeve and antifriction bearings may be selected. Oil supply and oil cooling systems complete with electric or shaft-driven mechanic oil pumps and monitoring for reliable operation are part of our scope of supply.

Terminal boxes

Connection boxes for power termination are usually located on top of the NDE bearing housing at IP23 generators or on the side of the NDE bearing shield at totally enclosed alternators with top-mounted coolers. Enclosure type for all terminal boxes is IP54.

The main terminal box is performed with 4 studs: 3 terminals for power connection L1-L2-L3 and 1 terminal for neutral connection. The neutral point is connected of the 3 neutral side winding ends after passing the neutral current transformers that are usually included for measuring and/or protection features. If required, the terminal box can be modified for housing further CTs or VTs.

All low voltage and signal connections are performed in an auxiliary terminal box located at the frame side.

Enclosure type

EN 60034-5 / VDE 0530-5
Standard design is IP23. Application of air inlet/dust filters as well as higher protection mode as IP43, IPR 44, IPR 54, IP44 and IP54 etc. are available on request.

Cooling mode

EN 60034-6 / VDE 0530-6
Standard design is IC01, direct air-ventilated. IC31 (cooling air channel connection), IC0161 (top-mounted air-to-air heat exchanger), IC8A1W7 (top-mounted water cooler) or any other solution can be offered on special request.

Design

EN 60034-7 / VDE 0530-7
The basic design modes are IM1001 (B3) and IM1101 (B20) for horizontal mounting and IM 3011 (V1) for vertical mounting.

Principally we confirm for WKV alternators: Every requested design our customers need is possible!