MECHANICAL SPECIFICATIONS

1. CONSTRUCTION

All GSA type synchronous alternators are designed as brushless and rotating-field machines Alternators consist of three main components, which are the main machine with exciter pole, exciter machine with external pole and permanent magnets, voltage regulator.

Main stator which is made of high quality siliceous laminations is mounted by means of supporting ribs in a sheet steel body. Main stator grooves and main rotor poles are designed to ensure low distortions and main stator windings have a shortened pitch to reduce the harmonic effects on the waveform.

The rotor is designed as salient-pole type, damper windings are placed into the rotor as a standard feature for parallel work and unbalanced loads. Fan, the main rotor assembly, exciter rotor and the rotating diodes are fitted to shaft . The entire rotor is dynamically balanced.

The exciter rotor has a three phase winding. The exciter rotor leads are connected to the rotating diodes arranged in three phase bridge configuration. Diodes are protected against voltage peaks by surge suppressor. Diodes and suppressor are easily accessible from rear shield.

The terminal box, which houses the voltage regulator, main terminal and potentiometer, is mounted on the steel body. Cast iron rear shield carries exciter stator. The flange of drive machine can be bolted to the outer face of the front shield of double bearing alternator or to the SAE adaptor of sigle bearing alternator. In double bearing alternator, alternator shaft is mounted to the drive machine’s shaft by flexible coupling, in single bearing alternator coupling disc is directly mounted to the driver machine’s flywheel. Our standard production is suitable for direct coupling. If the belt driven pulley application is necessary, please contact to our company for further information.

2. SHAFT

The shafts of the alternators are made of high quality steel. Each shaft-end is equipped with a centering-thread according DIN 332, form D for fitting belt pulleys, couplings, bearings etc. The driven shaft ends of double bearing alternators  are delivered with key according DIN 6685, sheet 1.

3. COOLING

Air intake is designed in order to obtain optimum air flow for cooling the coils. Appropriate cooling prolongs the coiling life. The fan is designed appropriately for high efficiency, minimum power loss and low noise level. Air inlet and outlets are placed to obtain uniform cooling of the alternator.

4. DIRECTION OF ROTATION

GSA type alternators can rotate in both directions without effecting the air suction. When looked at the back cover of the alternator the U-V-W placement in the output terminal will correspond to a counterclockwise direction.

5. OVER SPEED

The alternators are designed so that they are capable of running at 20% of the rated speed for 2 minutes as specified in VDE 0530.

6. OUTPUT TERMINAL

Six poled output is Y-connected as a standard. The stator output can also be delta-connected. In case of a delta connection the output power calculated by multiplying the power in the alternator's label with a coefficient. Please consult our company for this application.

7. BEARINGS AND LUBRICATION

GSA 27 type alternators are equipped with life-lubricated, maintenance-free bearings. In GSA 34, 42 and 53 type alternators regreasable  ball bearings are used with grease regulator. The amount of grease in the bearings is regulated automatically and over heating is prevented.