4 pole, screen protected, drip-proof IP23, self-exciting, self-regulating and brushless with fully connected damper windings, salient pole rotors, A.C. exciter and rotating rectifier unit. The insulation system is Class ’H’. All windings are impregnated in either a triple dip thermo-setting moisture, oil and acid resisting polyester varnish or vacuum pressure impregnated with a special polyester resin. Electrical design in accordance with BS5000 Part 3, VDE0530, UTE51100, NEMA MG1-32, CEMA, IEC34-1, CSA22.2 and AS1359.
6 and 12 wire*1 reconnectable windings provide a wide range of 3 phase voltage. The exciter field system remains at full strength, sustaining a high level of short circuit current at the ac generator output terminals by means of the excitation voltage via AVR powered by the independent winding, Permanent Magnet Generator (PMG) as a standard feature in the MGS genset, which is electrically isolated from the main alternator stator windings.
The fully sealed, three phase*2 RMS voltage sensing AVR maintains the voltage within the limits of +/-0.5%*3 from no load to full load including cold to hot variations at any power factor between 0.8 lagging and unity allowing for a 4% engine speed variation, suitable for applications with greatly unbalanced or high non-linear loads associated with UPS systems. The AVR has built-in protection against sustained over-excitation, caused by internal or external faults. This de-excites the generator after a minimum of five seconds. THF (as defined by BS4999 Part 40) is better than 2 % and a TIF (as defined by ASA C50.12) is better than 50. Radio interface: Suppression is in line with the provision of BS800 and VDE Class G and N.
Note. *1 . 12 wire reconnectable windings are the features up to Code H6 models. *2, 3 .Up to Code K5 models have single phase voltage sensingand the voltage regulation within +/-1.0%, for 4% engine speed variation. Turbo-filter is standard and paper element dry type air-cleaner is available as an option.