... models, with 50Hz or 60Hz frequency, Single bearing or Double bearing, brushless, Self-excited. Abounds with almost every model ... Insulation and ProtectionInsulation: H, Protection: IP22 IP23 is for optional but the rated power will decrease 5%. Voltage ... genetator sets3) Balance rotor with single or two sealed ball bearings available,4) Convenient installation and easy maintenance, easy access ...