Balancing; Assembly Of Adaptors And Discs For Mjb - MarelliMotori MJB 160 Nstrucciones Y Advertencias De Seguridad

Do not touch power terminals during and immediately after the insulation resistance check because the winding is in voltage.
To measure the insulation resistance, proceed in the following way:
Concerning the windings of the main stator (see diagram), the insulation resistance measurement must be conducted taking care to
detach the connections leading to the regulation devices (voltage regulator or other devices) or to any other group devices. The
measurement is taken between one phase and ground with the remaining two phases also connected to ground (the operation must be
conducted on all three phases).
Concerning the exciter-stator, detach the + and – cables from the regulator and measure the insulation resistance between one of
these two terminals of the winding and ground.
Concerning the rotor windings, measure the insulation resistance between one terminal of the winding of the main rotor on the rectifier
bridge and the rotor ground (shaft).
The values measured are recorded. If in doubt, also measure the polarisation index. (§ 4.8)
In order to prevent risks of electric shock, connect the windings briefly to the ground immediately after measurement.
In order to be able to make a correct comparison of the measured insulation resistance values, they are referred to 20°C.
A correction coefficient is applied for different temperatures:
( )
( )
= ⋅
R K R
°
isol c
20 C
Example: R = 50 MΩ at the winding temperature of 30°C;
mis

4.2 Balancing

Unless otherwise indicated the rotor is balanced dynamically with a half-key fitted on the shaft extension, in compliance with IEC 34-14.

4.3 Assembly of adaptors and discs for MJB 160

For the MJB 160 type only, in case the assembly of adaptors and discs is carried out directly on the shaft-end, proceed as follows:
- Deeply clean the machined surfaces for the coupling of the adaptor and frame, and make sure that they are not damaged.
- Fit the adaptor up on the frame with n°6 screws M10X50 (cl 8.8), washers and nuts. Put on the screws some drops of LOCTITE
243 (picture 1), and cross-tighten them through a 48Nm torque wrench (picture 2).
- Deeply clean the shaft-end by means of a detergent.
- Make sure that the disc's contact surface is not damaged.
- Insert the spacer "A" in the shaft, the coupling disc and the washer "B". Tighten the parts with n°6 screws M10 class 12,9
supplied in the kit (picture 3), put on the screws some drops of LOCTITE
75Nm torque wrench (picture 4).
Photo 2
48Nm
Photo1
SIN.UM.805.6
Twinding (°C)
mis
T
Kcorrection
Photo 3
A
T 15 20
Kc 0.69 1
⋅ (R = 2 ⋅ 50 = 100 MΩ
(R ) = K )
isol 20°C c mis 30°C
®
243 (picture 1), and cross- tighten them through a
B
6
25 30 35
1.42 2 2.82
Photo 4
75Nm
963857153_F
ENGLISH
40
4
®