B4V

Housing
Rigid frame, rugged welded steel fabrication (EN 10025 - S235 JR). Frame is provided with side ribs to increase the strength. Marelli Motori motors for continuous duty operation are designed to meet vibration levels per IEC 60034-14, ISO 10816-1 and BS 5000-3.

Shield
Made of grey cast-iron (EN 1561 – GJL 200) up to 500 frame size motors.
Made of hot-rolled structural steel (EN 10025 – S235 JR) from size 560 and above.

Shaft
General data - Made in carbon steel (EN 10083 – 2 C40 – TN) up to 450 frame and hot-rolled structural steel from 500 frame (EN 10025 – S355 JR). 
Shaft design - Cylindrical shaft with key.

Main terminal box

 Mounted on side (right or left to be selected).
Made of formable steels EN 10130.

Internal Fan

 Made of aluminum alloy up to 400 frame.
Made of hot-rolled structural steel above (EN 10025 – S235 JR).

Heat Echanger
Construction

• mounted on top of the machine
• double tube made of CuNi 90/10
• copper fins housing
• equipped with water leakage detector
• certified by registers of shipping in compliance with Rules for Classification of Ship
• coolant can be both fresh or sea water
• suitable to be treated with corrosion inhibitors, PH regulators and anti freeze as appropriate to site conditions.

Exchanger data

• designed pressure 6 bar
• test pressure 10 bar
• max glycol: 30%
• type of water: fresh water or marine (salt) water
• flanges: PN6 – PN10 – Special (ANSI).

Cooling System
IC 81W as per IEC60034-6. Primary fluid (water) is flowing by external water system. Internal air is flowing by a fan mounted on the shaft of the generator at the driven side.

Degree of protection
IP 44 as per IEC60034-5. (Available up to IP 56)

Mounting
IM B3, V1 and V10 as per IEC60034-7.

Certificate
Marine Survey Certificate supplied with the machine.
Shaft, housing (propulsion) and exchanger are certified by the Marine Classification Society.

Stator/Rotor core
Laminated and enamel-insulated on both sides to minimise eddycurrent losses. The stator winding is made of flat copper or round copper wire depending on the machine size.
The completely wound stator pack is thereby impregnated in an epoxyresin VPI. The subsequent heat treatment hardens the resin.

Rotor
Squirrel cage rotor type.
Depending on machine size, the rotor construction is either a solid shaft or welded ribbed shaft. The rotor winding can be either a pressure die cast aluminum or a copper bar construction.

Bearing
Antifriction bearings grease lubricated (ball or roller type) or oil lubricated sleeve bearing.
The theoretical lifetime of bearings, L10h according to ISO 281/1 standard, of standard horizontal construction generators, without external forces (radial and / or axial) is in excess of 50.000 hours. On request, the lifetime of bearings, L10h can be in excess of 100.000 hours.
Locating bearings are on the D end side and floating bearings on the ND end side.
Both bearings are fitted with a regreasing system.

The used grease is removed through a valve locked in the outer bearing cover. Sleeve bearings available as an option. 
On request special bearings are designed where high radial and axial forces are applied. All configurations are designed to withstand the following marine inclination.

Static

List: 15°
Trim: 5°

Dynamic
Rolling: ±22.5°
Pitch: ±7.5°

Dedicated constructions available for different values.

Impregnation system

 Stator and rotor are VPI treated with an unsaturated polyester amide resin which is polymerisation in oven.

Insulation system
Low voltage
Stator: F class insulated with a synthetic enamel. (H class insulation available on request)

Protective treatments
Marine dedicated protective enamel is applied on the winding.

Optional features

• Dual/multiple winding configuration
• flanged shaft or special shaft end on both sides
• increase protection degree up to IP 56
• encoder
• vibration sensors
• special frame design to suite the application
• special bearings (sleeve or angular contact bearings)
• reinforced winding for VFD operation
• insulated bearings design for VFD application
• shaft earth brush for VFD application
• other options available on request.